82
Amine-templated
anionic metal-organic frameworks with the 4,4'-(hexafluoroisopropylidene)
bis(benzoic acid) ligand
Wang, Xiqu; Liu, Lumei; Conato, Marlon; Jacobson, Allan J.
Three compds. with anionic metal-org. frameworks [M3(hfbba)4]2-, M = Mn2+
or Co2+, H2hfbba = 4,4'-(hexafluoroisopropylidene)bis(benzoic acid), were
synthesized by solvothermal techniques in the presence of different amines.
Their structures were detd. from single crystal x-ray
data. All three structures are based on linear trimers of metal oxide
polyhedra. (C6H11NH3)2Mn3(hfbba)4, 1, has a 3D
structure with large cages that are filled by pairs of cyclohexylammonium
cations. ((C4H11)2NH2)2Co3(hfbba)4, 2, has a complex
layered structure with intralayer lateral channels. One half of the
dibutylammonium cations are located inside the channels and are orientationally
disordered, while the other half of the dibutylammonium cations are located in
the interlayer spaces and are ordered. (H2tdpip)Co3(hfbba)4,3,
tdpip = 4,4'-trimethylenedipiperidine, also has a layered structure with the
H2tdpip cations located between the layers. The magnetic
properties of all compds. were detd. from 10 to 300 K.
81
Covalently
interconnected and separated vanadosilicate shells
Wang, Xiqu; Liu, Lumei; Jacobson, Allan J.
Four new compds. contg. vanadosilicate clusters have
been synthesized by hydrothermal reactions. The clusters are derived from the
[V18O42] Keggin cluster by substitution of V=O caps by Si2O(O,OH)2
species. In Cs9[(V15Si6O46(OH)2Cl)(V2O4)](H2O)6.2, 1,
the [V15Si6O46(OH)2] cluster shells are covalently interconnected by VO4
tetrahedra to form an infinite layer. In
((CH3)4N)4[V15Si6O42(OH)6(H2O)](H2O)20, 2, and ((CH3)4N)4(V(H2O)6)2/3
[V15Si6O42(OH)6H2O)](H2O), 3, sepd. [V15Si6O42(OH)6] cluster shells are
interlinked by hydrogen bonds to form frameworks with wide channel systems. The
sepd. cluster shell in ((CH3)4N)4((CH3)2NH2)((CH3)2NH)
[V14Si8O42(OH)8(HCO2)](H2O)4.7, 4, has four Si2O(OH)2 species in a tetrahedral
configuration. The 2D structure of 1 and 0D structures of 2-4 complement the
known 1D and 3D structures formed from such vanadosilicate shells.
80
Breathing
and Twisting: An Investigation of Framework Deformation and Guest Packing in
Single Crystals of a Microporous Vanadium Benzenedicarboxylate
Wang, Xiqu; Eckert, Juergen; Liu, Lumei; Jacobson, Allan J.
The structural
details of the compds. V benzenedicarboxylate VO(bdc)·Guest,
where the Guests are the absorbed six-ring mols.: benzene, 1,4-cyclohexadiene,
1,3-cyclohexadiene, cyclohexene and cyclohexane, were detd. from
single crystal x-ray data. Crystallog. data are given. All of the six-ring guest mols. show a high degree of ordering inside the channels of
VO(bdc). The interactions between the guests and the host framework are
dominated by van der Waals bonding. The six-ring mols.
are all packed in two columns in the channels, either
in herringbone or close to parallel patterns. The packing changes the space
group symmetry of VO(bdc) from Pnma to the
noncentrosym. space group P212121. The VO(bdc) framework deforms to closely adapt to the shape and
thickness changes of the double columns of the guest mols. In addn. to the well
studied breathing deformation, a twisting deformation mechanism that involves a
cooperative rotation of the octahedral chains accompanied by bending of the bdc
ligand is apparent in the detailed structural data. More quant. information on
the remarkable flexibility of the VO(bdc) framework
was obtained from ab initio calcns.
79
Influence
of Ligand Geometry on the Dimensionality of Sn(II)
Benzenedicarboxylate Crystal Structures
Wang, Xiqu; Liu, Lumei; Makarenko, Tatyana; Jacobson, Allan J.
Four new divalent tin benzenedicarboxylates
(bdc) were synthesized by hydrothermal techniques, and their structures were
detd. from single crystal x-ray data. A chiral complex
layer is formed by Sn(II) and 1,2-bdc. In [Sn(1,2-bdc)] (2), such layers are stacked in a AA pattern, leading
to a chiral and polar structure with the space group symmetry C2, while in
[Sn(1,2-bdc)] (1) the same layer is alternately stacked with the mirror-image
layer, leading to a structure with the space group C2/c. The 1-sided
coordination of Sn(II) combined with the 120° angle of the carboxylate groups
in 1,3-bdc results in the tubular structure of [Sn(1,3-bdc)] (3). The tubes are
connected by very weak intertube Sn-O bonds. The compd. [Sn3O(1,4-bdc)2]
(4) has a 3-dimensional framework structure based on Sn3O triangular secondary
building units that are cross-linked by the 1,4-bdc ligands. Strong
π-π interactions occur between the neighboring Ph rings.
78
Hydrothermal
synthesis, structures, and optical properties of lanthanum stilbendicarboxylic
acids
Gil-Mateo,
Paola; Jacobson,
Allan J.Wang, Xiqu
Three stilbenedicarboxylic acids La4(SDC)6(H2O)8 (1), (LaX)4(SDC)6(H2O)8 (X=Ce (2), Eu (3),
5%), (SDC = 4,4'-stilbenedicarboxylic acid) were synthesized by hydrothermal
reactions and their structures detd. from single crystal X-ray diffraction. Compds. 1, 2 and 3 crystallize in space group P21/n, with
lattice parameters a = 19.816(9) Å, b = 5.456(3) Å, c = 19.901(2) Å, β =
108.59 (1)°. LaO8 polyhedra are cross-linked by 2 SDC
ligands forming infinite layers perpendicular to the layer stacking direction.
Lanthanum oxide hydrate infinite layers are linked by 2 SDC ligands. The
fluorescence properties and emission decays of solid samples were analyzed. Compds. 2 and 3 exhibit a red shift at the excitation wavelength
with respect the H2SDC ligand. Emission decays were fit best by a single
exponential function for all the compds. Emission lifetime of compd. 1, 2 and
H2SDC were estd. to be 3.68 ns, 1.95 ns and 2.75 ns.
77
Acentric
and Centric Interpenetrations of an Anionic Framework Mediated by Cation Sizes:
The Alkali-Metal Tin(II) Benzenedicarboxylates
A2Sn2(bdc)3(H2O)x (A = Li, Na, K, Rb, Cs)
Wang, Xiqu; Liu, Lumei; Makarenko, Tatyana; Jacobson, Allan J.
Alkali-metal tin 1,4-benzenedicarboxylates,
A2Sn2(bdc)3(H2O)x, A = Li, Na, K, Rb, Cs, in single crystal forms were
synthesized by using a hydrothermal technique and characterized by x-ray
crystallog. The compds. all
have cubic crystal structures based on a very open anionic [Sn2(bdc)3]2-
framework which is 8-fold interpenetrated noncentrosym. (space group I23) in
Li2Sn2(bdc)3(H2O)2 (1), K2Sn2(bdc)3 (3), Rb2Sn2(bdc)3 (4) and Cs2Sn2(bdc)3 (5),
but centrosym. (space group Pn.hivin.3) in
Na2Sn2(bdc)3(H2O) (2). The ion size and coordination requirements of
the alkali ions play an important role in the interpenetration of the anionic
framework and the symmetry of the structures.
76
AlF·1,4-benzenedicarboxylate: synthesis and absorption properties
Liu, Lumei; Wang, Xiqu; Jacobson, Allan J.
AlF(bdc), bdc =
1,4-benzenedicarboxylate, a new member of the family of MX(bdc) compds. was synthesized under solvothermal conditions. It is formed
without H2bdc in the channels and substantial absorption capacity is obsd. in its as-synthesized form. AlF(bdc)
does not absorb water at ambient temps. and shows
absorption properties similar to VO(bdc).
75
Open
layers based on metal-oxide chains linked by cyclohexanedicarboxylate ligands
Kim, Inn-Hoe; Wang, Xi-Qu; Jacobson,
Allan J.
Three layered metal-oxide org. compds., In(OH)(1,4-chdc)
(1), Cr(OH)(1,4-chdc) (2), and In(OH)(1,2-chdc) (3), (H2chdc =
cyclohexanedicarboxylic acid) were synthesized and characterized by
thermogravimetric anal., IR spectroscopy, and X-ray diffraction. All three
structures are formed by stacking electro-neutral layers in a simple AA
sequence. The layers are built by crosslinking -OH-M-OH-M- chains with the chdc
anions. Unlike the flat 1,4-benzenedicarboxylate
ligand which was previously shown to connect similar metal-oxide chains into
porous 3D frameworks, the bent chdc ligands link the chains to form open layers
with narrow intra-layer channels. From a mixt. of cis- and trans- conformations of 1,4-chdc, only the
e,a-cis conformation is incorporated in 1 and 2.
74
Synthesis
and structures of novel lanthanide benzenedicarboxylates
Gil-Mateo, Paola; Wang, Xiqu; Jacobson, Allan J.
Three novel lanthanum
benzenedicarboxylates La2(BDC)3(H2O)4 (1), La4(BDC)3(OH)6 (2) and
La3(BDC)2(OH)5 (3) (BDC = 1,4-benzenedicarboxylate) were synthesized by
hydrothermal reactions and their structures detd. from
single crystal x-ray diffraction. All three compds. are 3-dimensional framework structures consisting of layers
of LaOn polyhedra cross-linked by BDC ligands along the layer stacking
direction. In 1 the layers contain sepd. [LaO6(H2O)2]
polyhedra that are bridged by the carboxylate groups of the BDC anions. Compds. 2 and 3 both have highly condensed lanthanum
oxide-hydroxide polyhedra. In 2 the layers are wavy and consist of [LaO5(OH)4] and [LaO4(OH)5] polyhedra that share common
corners, edges, and faces. In 3, the layers are similar but comprise [LaO3(OH)5] and [LaO4(OH)5] polyhedra.
73
Syntheses
and structures of Ta2(WO2)0.87H0.26(PO4)4 and
Ta2(MoO2)(PO4)4.
Rungrochaipon, Pesak; Wang, Xiqu; Jacobson, Allan
J..
Department of Chemistry, University of Houston, Houston,
TX, USA. Materials Research Bulletin (2009), 44(3),
688-692. Publisher: Elsevier Ltd., CODEN: MRBUAC ISSN: 0025-5408. Journal written in English. AN 2009:142365 CAPLUS
(Copyright (C) 2009 ACS on SciFinder (R))
Abstract
Tantalum
hydrogen phosphate, b-TaH(PO4)2, has a three-dimensional structure that is stable
to remarkably high temp. (.apprx.600 °C)
presumably due to the presence of strong hydrogen bonds. Impedance measurements indicate a low cond.,
2.0 ´ 10-6 S/cm at 200 °C in 5% H2. In
further studies aimed at enhancing the cond. by aliovalent doping, we have
investigated systematically the synthesis of compds. in
the TaH(PO4)2-W2P2O11 system at 380 °C. As a result, a new
phase, Ta2(WO2)0.87H0.26(PO4)4, was identified and
subsequently the molybdenum analog Ta2(MoO2)(PO4)4 was also prepd. The structures were detd. by
single crystal X-ray diffraction techniques.
The structures of Ta2(WO2)0.87H0.26(PO4)4 and Ta2(MoO2)(PO4)4
can be formally derived from the structure of b-TaH(PO4)2 by the replacement of two P-OH protons with an
MO2 2+ (M = Mo and W) group together with a change in the orientation of some
phosphate tetrahedra.
72
On the optimization of bond-valence
parameters: artifacts conceal chemical effects. Wang, Xiqu; Liebau,
Friedrich. Department of
Chemistry, University
of Houston, Houston, TX,
USA. Acta Crystallographica,
Section B: Structural Science
(2009), B65(1), 96-98.
Publisher: Wiley-Blackwell, CODEN: ASBSDK ISSN: 0108-7681. Journal written in English. AN 2009:68837 CAPLUS
(Copyright (C) 2009 ACS on SciFinder (R))
Abstract
We recently proposed that calcd. bond-valence sums, BVS, represent a non-integer structural
valence, 'structV', rather than the integer-value stoichiometric
valence, stoichV. Therefore,
the usual attempts to 'optimize' bond-valence parameters r0 and b by adjusting
them to stoichV are based on the false assumption that numerical values of structV
and stoichV are always equal.
Bond-valence calcns. for
several compds. with stereoactive cations SnII,
SbIII and BiIII reveal the balanced distribution of the
bonding power structV between atoms of each structure.
71
Stoichiometric valence and structural
valence--two different sides of the same coin: "bonding power". Liebau Friedrich; Wang Xiqu; Liebau
Waltrude Institut fur
Geowissenschaften, AG Kristallographie, Universitat Kiel, Olshausenstr. 40, 24098 Kiel, Germany.
liebau@min.uni-kiel.de
Chemistry (Weinheim an der Bergstrasse, Germany) (2009), 15(12),
2728-37. Journal code:
9513783. E-ISSN:1521-3765. Germany: Germany, Federal Republic of. Journal; Article; (JOURNAL ARTICLE) written in
English. PubMed ID 19191239 AN
2009195311 MEDLINE (Copyright (C) 2009
U.S. National Library of Medicine on SciFinder (R))
Abstract
Recent
studies use the term valence to describe two distinct aspects of the phenomenon
bonding power of an atom. Measured in
valence units, one valence term, the classical chemical valence, has integer
values and is derived solely from the composition of a compound. The second one, used mainly by solid-state
physicists and crystallographers, has non-integer values. It is determined from structure data, which
are derived from diffraction experiments, spectroscopy, or quantum-chemical
calculations. To distinguish clearly
between these two types of valencies, the descriptive terms stoichiometric
valence and structural valence and the respective symbols (stoich)V and (struct)V should be used. For the majority of crystalline structures,
values of (stoich)V and (struct)V, both measured in
valence units, differ by less than 5%.
However, for p-block atoms with one lone electron pair, differences
between (stoich)V and (struct)V of up to 30% have been
reported.
70
A
bond-valence investigation of two series of isostructural lanthanide compounds. Liebau, F.; Wang, X. Institut fuer Geowissenschaften, AG
Kristallographie,
Universitaet Kiel,
Kiel, Germany. Acta Crystallographica, Section B:
Structural Science (2008), B64(3),
299-304, S299/1. Publisher:
Wiley-Blackwell, CODEN:
ASBSDK ISSN: 0108-7681. Journal written in English. AN 2008:601651 CAPLUS
(Copyright (C) 2009 ACS on SciFinder (R))
Abstract
Since the days of Pauling it has been
tacitly assumed that the valence, which is distributed between the bonds to
neighboring atoms, is the stoichiometric valence, stoichV, which has integer
values. It is shown here that this is
not true. Instead, bond-valence sums
(BVS) calcd. for lanthanide (Ln) atoms of a series of
garnet-type compds. LnIII3TeVI2LiI3O12 deviate significantly from stoichV. Values of (BVS)Ln of
this series, plotted vs. the element no. ZLn, show the same irregular sequence
as: (i) the third ionization potentials of Ln atoms, (ii) the valence values
previously calcd. with quantum-chem. methods for
lanthanide metals and sulfides, and (iii) the exptl. efficiencies of the
reactions between LnI and SF6 in the gas phase.
This indicates that in the Ln3Te2Li3O12 series the BVS values of the Ln
atoms, which are 'rattling' in rather large and rigid voids of the structure, reflect the electronic structure of Ln. It is, therefore, concluded that BVS
represent a non-integer valence, which is based on the electronic structure of
bonded atoms, rather than stoichV. For
this non-integer valence the term 'structural valence' and the symbol structV
have been proposed. In another series of
lanthanide chelates the (BVS)Ln values deviate even
more from stoichVLn = 3 v.u. than in the garnet-type series. In the chelates the Ln atoms are 'squeezed'
in rather small voids so that the electronic effects of Ln acting on (BVS)Ln are overridden by stronger steric effects exerted by the
org. ligands.
69
Octahedral Tilting in MM'X4 Metal-Oxide
Organic Layer Structures. Vougo-Zanda, Marie; Anokhina, Ekaterina V.;
Duhovic, Selma; Liu, Lumei; Wang, Xiqu; Oloba, Oluwakemi A.; Albright, Thomas
A.; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
Three
metal-oxide org. frameworks have been synthesized and characterized: vanadium
1,4-benzenedicarboxylate, V2O2F0.6(OH)1.4(BDC)×0.4H2O (1); indium
1,4-benzenedicarboxylate, In2F2.2(OH)1.8(BDC)×1.6H2O (2); and
aluminum 1,4-benzenedicarboxylate Al2F3(OH)(BDC) (3). The three-dimensional structures of 1, 2, and
3 have the same framework topol. as the previously
reported vanadium (III) 1,4-benzenedicarboxylate, VIII2(OH)2F2(BDC). The frameworks consist of inorg. layers constructed from corner sharing ML6 octahedra (M = V,
In, Al and L = OH, F) linked by BDC ligands.
The structures are related to a general class of perovskite-related
layer structures with compn. MM'X4. The layers show characteristic distortions
that can be related to tilting of the ML6 octahedra. In particular the structure of 1 consists of
O-V distances that strongly alternate along the b axis. The electronic consequences of this
distortion then create a tilting of the 1,4-benzenedicarboxylate
ligand about the a axis. Crystal data:
1, orthorhombic, space group Pmna, a = 7.101(2) .ANG., b = 3.8416(11) .ANG., c
= 20.570(6) .ANG.; 2, orthorhombic, space group Cmcm, a = 7.490(4) .ANG., b =
21.803(1) .ANG., c = 8.154(4) .ANG.; 3, monoclinic, space group P21/m, a =
10.7569(8) .ANG., b = 6.7615(3) .ANG., c = 7.1291(3) .ANG., b = 76.02(1)°.
68
Tossing and Turning: Guests in the Flexible
Frameworks of Metal(III) Dicarboxylates. Vougo-Zanda, Marie; Huang,
Jin; Anokhina, Ekaterina; Wang, Xiqu; Jacobson, Allan J. Department of Chemistry, University of
Abstract
Single
crystals of Ga(OH)(C8H4O4)×0.74C8H6O4 (2)
and Ga(OH,F)(C8H4O4)×0.74C8H6O4 (3) were obtained under
hydrothermal conditions. The structures
of 2 and 3 have the same topol. framework as the
previously reported Al 1,4-benzenedicarboxylate (BDC), Al(OH)(C8H4O4)×0.7C8H6O4
(1). Crystallog.
data and at. coordinates are
given. The frameworks are built by
interconnecting M-OH-M chains (M =
67
Preparation
of porous metal organic framework materials for the removal of sulfur compounds
from hydrocarbon fluids. Jacobson, Allan J.; Liu, Lumei; Wang, Xiqu. (The University of Houston
System, USA). PCT Int.
Appl. (2008), 46pp. CODEN: PIXXD2
WO 2008021194 A2
20080221 Designated States W: AE,
AG, AL, AM, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, CA, CH, CN, CO, CR, CU,
CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU,
ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY,
MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PG, PH, PL, PT,
RO, RS, RU, SC, SD, SE, SG, SK, SL, SM, SV, SY, TJ, TM, TN, TR, TT, TZ. Designated States RW: AT, BE, CH, CY, DE, DK,
ES, FI, FR, GB, GR, IE, IS, IT, LU, MC, MT, NL, PT, SE, TR, BF, BJ, CF, CG, CI,
CM, GA, ML, MR, NE, SN, TD, TG. Patent written in
English. Application: WO 2007-US17729 20070809.
Priority: US
2006-836806 20060810. CAN 148:265700 AN
2008:224053 CAPLUS (Copyright (C) 2008 ACS on SciFinder
(R))
Patent Family Information
Patent No. Kind Date Application
No. Date
WO 2008021194 A2 20080221 WO 2007-US17729 20070809
WO 2008021194 A3 20080424
W:
AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, CA, CH, CN,
CO, CR, CU, CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,
HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, LK, LR, LS,
LT, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PG,
PH, PL, PT, RO, RS, RU, SC, SD, SE, SG, SK, SL, SM, SV, SY, TJ, TM, TN, TR, TT,
TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW
RW: AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI,
FR, GB, GR, HU, IE, IS, IT, LT, LU, LV, MC, MT, NL, PL, PT, RO, SE, SI, SK, TR,
BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR, NE, SN, TD, TG, BW, GH, GM, KE,
LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, ZM, ZW, AM, AZ, BY, KG, KZ, MD, RU, TJ, TM,
AP, EA, EP, OA
Priority Application
US 2006-836806P P 20060810
Abstract
An absorbent compn. for desulfurizing a hydrocarbon fluid is made of at least
one compd. of a class of porous metal org. compds. of
the general formula MOADA, where M is a tetravalent metal or a mixt. of tetravalent metals, O is an oxygen atom, and
66
Crystal growth of AlPO-5, AlPO-15, and AlPO-21
from aluminum foil. Rungrojchaipon, Pesak;
Wang, Xiqu; Jacobson, Allan J.
Department of Chemistry, University of
Abstract
Single
crystals of AlPO-n (AlPO-5, AlPO-15 and AlPO-21) were grown using Al metal as
the aluminum source and appropriate org. amines as templates. The influence of synthesis conditions on the
crystal size has been studied by systematically changing temp., the org.
template and the gel compn.
65
Influence of Ligand Geometry on the Formation of In-O Chains in
Metal-Oxide Organic Frameworks (MOOFs). Vougo-Zanda, Marie; Wang,
Xiqu; Jacobson, Allan J. Department of Chemistry, University of
Abstract
Three
indium-oxide org. frameworks, In2O(1,3-BDC)2 (1), In(OH)(2,6-NDC)(H2O) (2) and
In(OH)(2,7-NDC)(H2O) (3, H2BDC = benzenedicarboxylic acid and H2NDC =
naphthalenedicarboxylic acid), were synthesized and characterized by TGA, IR
spectroscopy, and single-crystal x-ray diffraction. Previously, the authors reported the
structure of In(OH)(1,4-BDC)×(0.75H2BDC) (0), where the framework is
built by interconnecting In-OH-In chains with the BDC anions to form large
diamond-shaped 1-dimensional channels filled with guest mols. Compds. 0-3 all
contain In-O(H) chains, but the coordination and
geometry depend on the nature of the dicarboxylate ligand. Compd. 0 contains In-O octahedral centers
that connect to form a single trans octahedral chain,
while in compd. 1, they connect to form a more complex double chain of
octahedra. Both
compds. 2 and 3 contain chains of connected pentagonal bipyramidal InO6(OH2) units. In
2, these units share trans vertexes that are cross-linked by chelating 2,6-NDC anions, whereas in compd. 3, cis vertexes are shared
to form chains that are linked by the 2,7-NDC anions.
64
(6,3)-Honeycomb structures of uranium(VI)
benzenedicarboxylate derivatives: the use of noncovalent interactions to
prevent interpenetration. Go, Yong Bok; Wang, Xiqu; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
Four two-dimensional coordination
polymers contg.
the uranyl cation (UO22+), (NH4)UO2(BDC)1.5.2.5H2O (1), KUO2(NDC)1.5.2H2O (2),
[C(NH2)3]UO2(NDC)1.5.2H2O (2b), and UO2(HBDC-Br)2 (3) (BDC =
1,4-benzenedicarboxylate, NDC = 1,4-naphthalenedicarboxylate, BDC-Br =
2-bromoterephthalate) were synthesized by hydrothermal reactions. Compds. 1-2b have
the same honeycomb (6,3) net but with 2-fold
interpenetration in 1 and without interpenetration in 2 and 2b. The use of 2-bromoterephthalate yields compd.
3 with a (4,4) net.
The structures of 2 and 2b show that the interpenetration can be
prevented by the addn. of a bulky substituent to the ligand. Maintaining the desired topol.,
however, requires a careful choice of the substituent group. Compds. 1, 2, and 2b
have a similar structural arrangement to that of benzenetricarboxylic acid
(trimesic acid, H3BTC). In H3BTC, the
six rings are formed by H bonding and the interpenetration is more complex than
that in 1. Crystal data: 1, triclinic,
space group P.hivin.1, a 10.453(8), b 12.316(9), c 13.441(10) .ANG., a 78.49(1), b 82.17(1), g 85.57(1)°, and Z = 4; 2,
monoclinic, space group C2/c, a 12.7795(9), b 19.728(1), c 15.379(1) .ANG., b 92.247(1)°, and Z = 8; 2b,
monoclinic, space group C2/c, a 12.7214(8), b 19.645(1), c 17.065(1) .ANG., b 98.896(1)°, and Z = 8; 3,
monoclinic, space group P21/c, a 7.873(5), b 18.358(14), c 6.893(5) .ANG., b 115.96(2)°, and Z = 2.
63
Intercalation of organic molecules into vanadium(IV) benzenedicarboxylate: adsorbate structure and
selective absorption of organosulfur compounds. Wang, Xiqu; Liu, Lumei;
Jacobson, Allan J. Department
of Chemistry,
University of
Abstract
The guest acid mols. of hydrothermally synthesized [V(O)(bdc)](H2bdc)0.71 (bdc =
benzenedicarboxylate) are removed to give high-quality single crystals of
[V(O)(bdc)]. On
adsorption of guest mols. from liq. phase, it
undergoes crystal-to-crystal transformation.
Furthermore, it also selectively adsorbs thiophene and di-Me sulfide
from methane.
62
Hydrothermal
synthesis and structures of the open-framework copper silicates
Na2[Cu2Si4O11](H2O)2 (CuSH-2Na), Na2[CuSi3O8] (CuSH-3Na),
Cs2Na4[Cu2Si12O27(OH)2](OH)2 (CuSH-4NaCs), and Na2[Cu2Si5O13](H2O)3 (CuSH-6Na). Wang, Xiqu; Liu, Lumei;
Wang, Lingbao; Jacobson, Allan J.
Department of Chemistry and Center for Materials Chemistry, University of
Abstract
A
series of open-framework copper silicates has been synthesized under mild
hydrothermal conditions. The frameworks
are based on double chains, single layers or double layers of SiO4 tetrahedra
interconnected by CuO4 squares or tetrahedra or CuO5 tetragonal pyramids. The structures contain 8-ring or 10-ring
channel systems with apertures up to 2.7 ´ 5.9 .ANG. which are filled by
alkali metal cations and water mols.
61
Open-framework copper titanosilicates. Wang, Xiqu; Liu, Lumei; Wang, Lingbao; Jacobson, Allan.
J. Department of Chemistry and Center
for Materials Chemistry,
University of
Abstract
Four
open-framework copper titanosilicates, (NaxH10-x)[Ti4(TiO)0.7Cu0.3Si12O38](H2O)y
(1), (Na9H)[Ti4CuSi12O38](H2O)6 (2), Na8CuTi3Si16O43 (3) and K4CuTiSi8O21 (4),
were synthesized by hydrothermal techniques.
The crystal structure of phase 1 detd. from single crystal x-ray data is closely similar to that
reported for the titanosilicate ETS-4 with .apprx.1/3 TiO5 pyramids randomly
replaced by CuO4 squares. Phase 2 also
has the ETS-4 structure but all the TiO5 pyramids are replaced by CuO4 squares
which are not randomly disordered. Phase
3 has the same structure as the mineral narsarsukite, a titanosilicate closely
related to the microporous titanosilicate ETS-10. Narsarsukite and ETS-10 have the same
straight single chains of TiO6 octahedra which are partially substituted by
CuO4 squares in 3. Phase 4 contains CuO4
squares and TiO5 tetragonal pyramids that crosslink a new type of silicate
double layer to form an open framework.
60
The contribution to bond valences by lone electron pairs. Wang, Xiqu.
Department of Chemistry, University of
Abstract
A review. Bond valence sums (BVS) calcd. for lone-pair cations are found increasingly higher than
their formal valences as the retraction of the lone electron pair (LEP) from
the nucleus is more pronounced. The
increase in BVS is interpreted as a continuous increase of an effective valence
of an atom that is a measure of its actual ability to bind other atoms without
changing its formal valence. How the LEP
of a lone-pair cation affects the effective valence of other atoms in a
structure is studied by bond valence calcns. for specific
structures. For structures rich in
alkali cations, it is found that the high effective valence of the lone-pair
cations tends to be balanced by low effective valence of alkali cations. The LEP transfers bonding power or effective
valence from the alkali cations to the lone-pair cations by joining the
coordination sphere of the alkali cations.
59
Stoichiometric valence versus structural
valence: Conclusions drawn from a study of the influence of polyhedron
distortion on bond valence sums. Liebau, Friedrich; Wang, Xiqu. Christian-Albrechts-Universitaet, Institut
fuer Geowissenschaften,
Kiel, Germany. Zeitschrift fuer Kristallographie (2005), 220(7),
589-591. Publisher: Oldenbourg
Wissenschaftsverlag GmbH,
CODEN: ZEKRDZ ISSN: 0044-2968. Journal written in English. AN 2005:844520 CAPLUS
(Copyright (C) 2005 ACS on SciFinder (R))
Abstract
From studies of the influence of
polyhedron distortions on bond valence sums (BVS), it is concluded that larger
deviations of the BVS values from corresponding values of their classical
valence are due to the fact that so far no distinction has been made between
the stoichiometric valence derived from chem. anal. and the structural valence derived from structure data.
58
In(OH)BDC× 0.75BDCH2 (BDC =
Benzenedicarboxylate), a Hybrid Inorganic-Organic Vernier Structure. Anokhina, Ekaterina V.;
Vougo-Zanda, Marie; Wang, Xiqu; Jacobson, Allan J. Department of Chemistry, University of
Abstract
The compd. In(OH)BDC×0.75BDCH2 (BDC = benzenedicarboxylate),
1, has been synthesized and characterized by single-crystal X-ray
diffraction. The structure comprises two
distinct sublattices formed by a covalently linked In(OH)BDC
lattice and ordered chains of hydrogen-bonded H2BDC mols. and
can be described as a hybrid inorg. coordination
polymer-org. vernier structure. Each
InO6 octahedron of the octahedral chain has a length of 3.6
.ANG. along the chain axis, whereas each H2BDC mol.
has a length of 9.6 .ANG. along the guest column
axis. Therefore, a unit of eight InO6
octahedra of the octahedral chain is just in registry with three H2BDC mols. of the guest column giving a repeat unit of 28.76 .ANG. along the channel axis direction.
57
Influence of the Reaction Temperature and
pH on the Coordination Modes of the 1,4-Benzenedicarboxylate
(BDC) Ligand: A Case Study of the NiII(BDC)/2,2'-Bipyridine System. Go, Yong Bok; Wang, Xiqu; Anokhina, Ekaterina
V.; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
Three new Ni(BDC)/2,2'-bipy compds.,
Ni2(BDC)(HBDC)2(2,2'-bipy)2 (2), Ni3(BDC)3(2,2'-bipy)2 (3), and
Ni(BDC)(2,2-bipy)2×2H2O (5), in addn. to the previously
reported Ni(BDC)(2,2'-bipy)×0.75H2BDC (1) and Ni(BDC)(2,2'-bipy)(H2O)
(4) [BDC = 1,4-benzenedicarboxylate; 2,2'-bipy = 2,2'-bipyridine], have been
synthesized by hydrothermal reactions. A systematic investigation of the effect of the reaction temp.
and pH resulted in a series of compds. with different compns. and
dimensionality. The diverse product
slate illustrates the marked sensitivity of the structural chem. of
polycarboxylate arom. ligands to synthesis
conditions. Compd. 1,
which has a channel structure contg. guest
H2BDC mols., is formed at the lowest pH.
The guest H2BDC mols. are
connected by hydrogen bonds and form extended chains. At a slightly higher pH, a dimeric mol.
compd. 2 is formed with a lower no. of protonated carboxylate groups per nickel
atom and per BDC ligand. Reactions at higher temp. and the
same pH lead to the transformation of 1 and 2 into the two-dimensional, layered
trinuclear compd. 3. As the pH is
increased, a one-dimensional polymer 4 is formed with a water mol. coordinated
to Ni2+. Bis-monodentate and bischelating
BDC ligands alternate along the chain to give a crankshaft rather than a
regular zigzag arrangement. A further
increase of the pH leads to the one-dimensional chain compd. 5, which has two
chelating 2,2'-bipy ligands. Crystal data:
2, triclinic, space group P.hivin.1, a = 7.4896(9) .ANG., b = 9.912(1)
.ANG., c = 13.508(2) .ANG., a = 86.390(2)°, b = 75.825(2)°, g = 79.612(2)°, Z = 2; 3,
orthorhombic, space group Pbca, a = 9.626(2) .ANG., b = 17.980(3) .ANG., c =
25.131(5) .ANG., Z = 4; 5, orthorhombic, space group Pbcn, a = 14.266(2) .ANG.,
b = 10.692(2) .ANG., c = 17.171(2) .ANG., Z = 8.
56
Metal-organic
frameworks based on iron oxide octahedral chains connected by
benzenedicarboxylate dianions. Whitfield, Tabatha R.; Wang, Xiqu; Liu, Lumei; Jacobson, Allan J. Department of Chemistry, Center for
Materials Chemistry,
University of
Abstract
Three new iron benzenedicarboxylates have
been synthesized by solvothermal techniques, and their structures detd. from
single crystal X-ray data: Fe(OH)(BDC)(py)0.85 (1), Fe(BDC)(DMF) (2), and
Fe(BDC)(py)0.42(DMF)0.25 (3) (BDC = 1,4-benzenedicarboxylate, py = pyridine,
DMF=N,N-dimethylformamide). Compds. 1 and 2 are the Fe(III)-
and Fe(II)-structural analogs of the known Cr benzenedicarboxylate compd. (MIL-53). Both contain trans
corner-sharing FeO6 octahedral chains connected by benzenedicarboxylate
dianions. Compd. 3 contains chains of
iron oxygen octahedra that share both corners and edges. Each chain is linked by BDC to six other
chains to form a three-dimensional framework.
Crystal data: 1, space group I2/a, a = 6.889(2), b = 11.073(3), c =
18.280(6) .ANG., b = 92.6(1)°; 2, space group
Pn21a, a = 19.422(2), b = 7.3022(5), c = 8.8468(7) .ANG.; 3, space group P21/n,
a = 9.234(2), b = 17.243(3), c = 9.978(2) .ANG., b = 93.9(1)°.
55
A
chain of changes: influence of noncovalent interactions on the one-dimensional
structures of nickel(II) dicarboxylate coordination
polymers with chelating aromatic amine ligands. Go YongBok; Wang Xiqu; Anokhina Ekaterina
V; Jacobson Allan J Department of
Chemistry, University of Houston, Houston, Texas 77204-5003, USA Inorganic chemistry (2004),
43(17), 5360-7. Journal code: 0366543. ISSN:0020-1669.
Abstract
Five
one-dimensional coordination polymers, Ni(BDC)(1,10-phen) (1), Ni(BDC)(2,2'-bipy).0.75H(2)BDC
(2), Ni(BDC)(1,10-phen)(H(2)O) (3), Ni(BDC)(1,10-phen)(H(2)O).0.5H(2)BDC (4)
and Ni(BDC)(2,2'-bipy)(H(2)O) (5) [where BDC = 1,4-benzenedicarboxylate,
2,2-bipy = 2,2'-bipyridine, and 1,10-phen = 1,10-phenanthroline] that have the
same topology but markedly different geometry and packing of the chains have
been synthesized by hydrothermal reactions.
The results of variations of synthesis conditions and substitutions of
1,10-phenanthroline with 2,2'-bipyridine indicate that incorporation of the
coordinating water molecule, which affects the degree of bending of the chain,
is primarily influenced by the amine ligand size, suggesting a substantial
structural role of aromatic-aromatic interactions and amine ligand steric
effects. The incorporation of the guest H(2)BDC molecules was found to be favored by lower pH
conditions. Crystal data: 1, monoclinic,
space group P2(1)/n, a = 9.5589(6) A, b = 12.6776(8) A, c = 13.5121(9) A, beta
= 95.437(1) degrees, Z = 4; 2, monoclinic, space group P2(1)/c, a = 20.532(3)
A, b = 21.505(3) A, c = 18.872(3) A, beta = 93.86(1) degrees, Z = 16; 3,
triclinic, space group P1, a = 8.618(3) A, b = 10.058(4) A, c = 11.353(4) A,
alpha = 115.31(1) degrees, beta = 92.33(1) degrees, gamma = 94.03(1) degrees, Z
= 2; 4, triclinic, space group P1, a = 9.7682(12) A, b = 10.6490(13) A, c =
11.2468(14) A, alpha = 76.685(2) degrees, beta = 65.309(2) degrees, gamma =
85.612(2) degrees, Z = 2; 5, monoclinic, space group P2(1)/c, a = 13.9683(9) A,
b = 17.4489(11) A, c = 13.7737(9) A, beta = 99.12(1) degrees, Z = 8.
54
Hydrothermal synthesis and structures of
the novel niobium phosphates [NbOF(PO4)](N2C5H7) and
[(Nb0.9V1.1)O2(PO4)2(H2PO4)](N2C2H10). Wang, Xiqu; Liu, Lumei; Jacobson, Allan J. Department of Chemistry, Center for
Materials Chemistry,
University of
Abstract
Two new Nb phosphates were synthesized
and their crystal structures detd. from single-crystal
x-ray data. [NbOF(PO4)](N2C5H7)
(1) (monoclinic, space group P21/c, a 11.442(1), b 9.1983(7), c 9.1696(8)
.ANG., b
109.94(1)°)
has a layered structure and is the 1st example of a neg. charged NbOF(PO4)
layer analogous to the MO(H2O)PO4 (M = V, Nb) layers. The layer charge is compensated by interlayer
4-aminopyridinium cations that adopt an unusual arrangement as a consequence of
H-bonding and p-p
interactions. The interlayer
aminopyridinium cations can be exchanged with alkylammonium ions which form
bilayers inclined at .apprx.65° to the NbOF(PO4) layer.
[(Nb0.9V1.1)O2(PO4)2(H2PO4)](N2C2H10) (2)
(orthorhombic, space group Pbca, a 15.821(2),b 9.0295(9), c 18.301(2) .ANG.)
has a disordered three-dimensional structure based on NbO(PO4) layers
cross-linked by phosphate tetrahedra and has a similar structure to the known V
analog [V2O2(PO4)2(H2PO4)] (N2C2H10).
53
Synthesis,
structure and properties of CsHSi3O7, a layered silicate with a chiral
structure. Wang, Xiqu; Liu, Lumei;
Huang, Jin; Jacobson, Allan J.
Department of Chemistry and Center for Materials Chemistry, University of
Abstract
The chiral layered silicate CsHSi3O7 was
synthesized by hydrothermal techniques, and its structure detd. by single crystal x-ray diffraction. The compd. crystallizes in the space group
P212121. The silicate single layer
consists of both four- and three-connected SiO4 tetrahedra and may be
considered as a member of layer structures (Si4O9)m(Si2O5)n. Strong H bonds occur between the terminal
52
Hydrothermal synthesis and structures of
the new open-framework uranyl silicates Rb4(UO2)2(Si8O20)
(USH-2Rb), Rb2(UO2)(Si2O6)× H2O (USH-4Rb)
and A2(UO2)(Si2O6)× 0.5H2O (USH-5A; A = Rb, Cs). Huang, Jin; Wang, Xiqu;
Jacobson, Allan J. Department
of Chemistry and Materials Research Science and
Abstract
Four new open-framework alkali metal
uranyl silicates, Rb4(UO2)2(Si8O20) (USH-2Rb),
Rb2(UO2)(Si2O6)×H2O (USH-4Rb), and A2(UO2)(Si2O6)×0.5H2O (USH-5A; A
= Rb, Cs), were prepd. hydrothermally at 245°. The structures of USH-2, -4, and -5 contain
UO6 tetragonal bipyramidal units connected by double chains, 4-membered rings,
and single chains of SiO4 tetrahedra, resp.
The compds. were
characterized by single crystal x-ray diffraction, SEM, UV-visible and IR
spectroscopy, and TGA.
51
Hydrothermal synthesis of a microporous
organic-inorganic hybrid framework [Fe0.28V0.72OH0.8(NH4)0.2(C8H4O4)]× 0.53(C8H6O4). Whitfield, Tabatha R.;
Wang, Xiqu; Jacobson, Allan J.
Department of Chemistry, University of
Abstract
Single crystals
of a novel org.-inorg. framework
[Fe0.28V0.72OH0.8(NH4)0.2(C8H4O4)]×0.53(C8H6O4), 1,
were prepd. by hydrothermal synthesis in the presence of an oxidizing
agent. The structure was solved by
single crystal x-ray diffraction: space group Pnma, a 17.6956(19) .ANG., b 6.8745(7) .ANG., c 11.9303(12) .ANG.. The three dimensional framework is
constructed from Fe/V-O chains that are cross-linked by 1,4-benzenedicarboxylate
(BDC) anions forming large 1-dimensional channels. As synthesized, the compd. contains addnl.
dicarboxylate groups occupying disordered positions in the channels that can be
removed by heating. The chem. reactivity
of 1 and its magnetic properties are reported.
The new phase is closely related to analogous Cr(III)
and V(III) phases recently reported by Ferey and co-workers.
50
Open framework and microporous transition
metal silicates. Jacobson, Allan J.; Wang,
Xiqu; Liu, Lumei; Huang, Jin.
Department of Chemistry, University of
Abstract
A review. A family of microporous and
open-framework microporous transition metal silicates were prepd. by
hydrothermal synthesis at T £ 240°. The structures of the compd. are based on a
common principle in which anionic silicate components (layers, chains, or
cluster anions) are connected by isolated transition metal polyhedra by sharing
four corners in a square arrangement. Known examples of this class of compds. are
reviewed and some recent progress on extending the syntheses to include org.
templates are discussed.
49
Nanoporous
copper silicates with one-dimensional 12-ring channel systems. Wang, Xiqu; Liu, Lumei;
Jacobson, Allan J. Department
of Chemistry,
University of
48
Synthesis and characterization of
mixed-valence barium titanates. Hoche, Thomas; Olhe, Paula; Keding, Ralf; Russel,
Christian; van Aken, Peter A.; Schneider, Reinhard; Kleebe, Hans-Joachim; Wang,
Xiqu; Jacobson, Allan J.; Stemmer, Susanne.
Otto-Schott-Institut,
Friedrich-Schiller-Universitat,
Jena, Germany. Philosophical Magazine (2003),
83(2), 165-178. CODEN: PMHABF ISSN: 1478-6435. Journal
written in English. CAN
138:307901 AN 2003:210688 CAPLUS
(Copyright 2003 ACS)
Abstract
A
single-crystal barium oxotitanate(III, IV) of approx. compn.
Ba5.93(Ti3+11.86Ti4+28.14)O80, contg. mixed-valence Ti, was grown from a borate
flux. The crystal structure was
identified as hollandite-type by single-crystal X-ray diffractometry. Electron-energy-loss spectroscopy of Ti L2,3
and O K edges was used to det. chem. shifts related to the presence of mixed-valence
Ti in the crystal. Comparison of Ti L2,3
and O K energy-loss near-edge structure.
Comparison of Ti L2,3 and O K energy-loss near-edge structure (ELNES) of
Ba5.93(Ti3+11.86Ti4+28.14)O80 with those obtained from a K1.54Mg0.77Ti7.23O16
single crystal with hollandite structure, contg. only Ti4+, revealed a shift in
the Ti L2,3 edge by 0.4-0.5 eV towards lower energy losses whereas only slight
intensity variations without a detectable energy shift of the edge onset occur
at the O K ELNES. In addn.,
valence-specific multiplet structures of the Ti L23 ELNES are used as valence
fingerprints. The obsd. fine structures
of O K and Ti L2,3 edges can be used to interpret coordination and bonding in
related compds.
47
Hydrothermal synthesis and structures of
the new open-framework uranyl silicates Rb4(UO2)2(Si8O20) (USH-2Rb),
Rb2(UO2)(Si2O6)×H2O (USH-4Rb) and A2(UO2)(Si2O6)×0.5H2O (USH-5A; A
= Rb, Cs). Huang, Jin; Wang, Xiqu; Jacobson, Allan
J. Department of Chemistry and
Materials Research Science and
Abstract
Four
new open-framework alkali metal uranyl silicates, Rb4(UO2)2(Si8O20) (USH-2Rb),
Rb2(UO2)(Si2O6)×H2O (USH-4Rb), and A2(UO2)(Si2O6)×0.5H2O (USH-5A; A
= Rb, Cs), were prepd. hydrothermally at 245°. The structures of USH-2, -4, and -5 contain
UO6 tetragonal bipyramidal units connected by double chains, 4-membered rings,
and single chains of SiO4 tetrahedra, resp.
The compds. were characterized by single crystal x-ray diffraction, SEM,
UV-visible and IR spectroscopy, and TGA.
46
Vanadogermanate Cluster Anions. Whitfield, T.; Wang, X.; Jacobson, A.
J.. Department of Chemistry and Center
for Materials Chemistry,
University of
Abstract
Three
novel vanadogermanate cluster anions have been synthesized by hydrothermal
reactions. The cluster anions are
derived from the
45
[(CH3)4N][(C5H5NH)0.8((CH3)3NH)0.2]U2Si9O23F4
(USH-8): An Organically Templated Open-Framework Uranium Silicate. Wang, Xiqu; Huang, Jin; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
The
open-framework uranium fluorosilicate
[(CH(3))(4)N][(C(5)H(5)NH)(0.8)((CH(3))(3)NH)(0.2)]U(2)Si(9)O(23)F(4) (USH-8)
has been synthesized hydrothermally by using tetramethylammonium hydroxide and pyridine-HF.
The compound has a framework composition U(2)Si(9)O(23)F(4) based on silicate
double layers that are linked by chains of UO(3)F(4) pentagonal bipyramids. The
framework has 12-ring channels along [010] and 7-ring channels along [100]. The
[010] 12-ring channels have a calabash-shape with the middle part partially
blocked by the uranyl oxygen atoms. The narrow side of the 12-ring channels is
occupied by well-ordered TMA cations while the wide side is occupied by
disordered pyridinium and trimethylammonium cations.
44
Hydrothermal synthesis and structures of
the novel niobium phosphates Ba2[NbOF(PO4)2] and Ba3[Nb3O3F(PO4)4(HPO4)](H2O)7. Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. Department of Chemistry and
Materials Research Science and
Abstract
The
new niobium phosphates Ba2[NbOF(PO4)2] (1) and Ba3[Nb3O3F(PO4)4(HPO4)](H2O)7
(2) were synthesized in single crystal form by hydrothermal reactions at mild
temps. Their crystal structures detd.
from x-ray diffraction data are based on defected derivs. of the NbO(H2O)PO4
layers found in hydrated niobium phosphate.
The niobium phosphate layers in 1 or 2 can be derived by removing 1/2 or
1/4 of the NbO6 octahedra from the NbO(H2O)PO4 layer, resp. In compd. 1 the layers are sepd. and are held
together by interlayer Ba-O and Ba-F bonds while in 2 the layers are linked by
interlayer PO4 tetrahedra to form a framework structure.
43
Microporous crystalline metal silicates
and processes for their preparation. Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. (The University of Houston
System, USA). PCT Int.
Appl. (2002), 62 pp. CODEN: PIXXD2 WO
0262703 A2 20020815
Patent written in English. Application: WO 2002-US3173 20020131.
Priority: US
2001-266252. CAN
137:171893 AN 2002:615517.
Patent No. Kind Date Application No. Date
WO 2002062703 A2 20020815 WO 2002-US3173 20020131
Priority Application
US 2001-266252P P 20010202
Abstract
New
bridged layered silicates are disclosed where the bridging groups bridge
adjacent silicate layers via oxygen atoms on each silicate layer that are
unshared to produce porous three dimensional structures. Methods for making these bridged layered
silicates are disclosed as well as methods for using these compns. as
catalysts, supports, adsorbents, drying agents and ion exchangers.
42
Open-Framework and Microporous Vanadium
Silicates. Wang, Xiqu; Liu,
Lumei; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
Novel
V silicates with open-framework and microporous structures were synthesized
under mild hydrothermal conditions. Ten
distinct framework types were identified that all have structures based on
crosslinking single silicate sheets with square pyramidal VIVO5 units to give
compds. Ar[(VO)s(Si2O5)p(SiO2)q]×tH2O, where A is
Na, K, Rb, Cs, or a combination. The
vanadosilicate (VSH-n) structures have free channel diams. up to 6.5 .ANG. and
show good thermal stability, absorption, and ion-exchange properties,
suggesting their potential for technol. applications as mol. sieves or in
catalysis.
41
Synthesis and characterization of an open
framework vanadium silicate (VSH-16Na). Huang, Jin; Wang, Xiqu; Liu, Lumei; Jacobson,
Allan J. Department of Chemistry and
Materials Research Science and
Abstract
A
new sodium vanadium(III) silicate, Na3V(Si4O11)×H2O (VSH-16Na1)
has been synthesized hydrothermally and its structure detd. by single crystal
X-ray diffraction. The compd.
crystallizes in the triclinic space group P1 with a=7.524(1) A, b=8.755(2) A,
c=9.055(2) A, a=62.486(3)°, b=83.998(3)°, g=88.692(3)°, V=525.9(2) A3,
and Z=2. The [SiO4] tetrahedra share
corners with each other to form unbranched [Si8O22]12- double chains. These chains are connected by isolated [VO6]
octahedra to form an open framework structure with eight-ring channels. The magnetic susceptibility data show
Curie-Weiss behavior down to 5 K and are consistent with the trivalent state of
the vanadium atoms.
40
The novel open-framework uranium
silicates Na2(UO2)(Si4O10)×2.1H2O (USH-1)
and RbNa(UO2)(Si2O6)×H2O (USH-3). Wang, Xiqu; Huang, Jin; Liu, Lumei; Jacobson,
Allan J. Department of Chemistry and
Materials Research Science and
Abstract
The
new open-framework uranium silicates Na2(UO2)(Si4O10)×2.1H2O (USH-1)
and RbNa(UO2)(Si2O6)×H2O (USH-3) were synthesized by
hydrothermal reactions at 230°. USH-1 has a framework structure formed from
silicate single layers cross-linked by interlayer UO6 tetragonal
bipyramids. The silicate layers consist
of interconnected tetrahedral 4-rings and 8-ring voids. The 8-ring voids are lined up to form
1-dimensional channel systems in the framework.
In contrast to the silicate layers of USH-1, individual 4-rings of
silicate tetrahedra are found in USH-3 which are cross-linked by UO6 tetragonal
bipyramids to form an open framework.
39
An extended chain structure formed by
covalently linking polyoxovanadate cages with tetrahedral six rings. Wang, Xiqu; Liu, Lumei; Zhang, Ge; Jacobson,
Allan J. Department of Chemistry and
Materials Research Science and,
Abstract
The
compd. Cs10.5[(V16O40)(Si4.5V1.5O10)]×3.5H2O (1) was
prepd. and is the 1st example of an extended structure in which a polyoxometalate
anion is linked by an extended tetrahedral unit. The shell can be considered as a deriv. of
the a-Keggin
cluster shell [V12O36]. The 6 square
windows of the a-Keggin shell can be capped by V=O groups
to form a [V18O42] shell. Substitution
of two VO5 pyramids of the [V18O42] shell by Si2O7 dimers leads to the
[V16Si4O46] unit of 1. Neighboring
[V16Si4O46] shells are linked together by (V1.5Si0.5)O4 tetrahedra to form
infinite chains running along [001]. 1
Was characterized by single crystal x-ray diffraction anal.
38
Anion-Directed Crystallization of
Coordination Polymers: Syntheses and Characterization of
Cu4(2-pzc)4(H2O)8(Mo8O26)×2H2O and
Cu3(2-pzc)4(H2O)2(V10O28H4)×6.5H2O (2-pzc =
2-Pyrazinecarboxylate). Zheng, Li-Min; Wang, Yongsheng; Wang, Xiqu; Korp, James
D.; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
Two
new copper 2-pyrazinecarboxylate (2-pzc) coordination polymers incorporating
[Mo8O26]4- and [V10O28H4]2- anions were synthesized and structurally
characterized: Cu4(2-pzc)4(H2O)8(Mo8O26)×2H2O (1) and
Cu3(2-pzc)4(H2O)2(V10O28H4)×6.5H2O (2). Without the presence of the cluster anions,
the mononuclear compd. Cu(2-pzc)2(H2O)2 is pptd. Presumably, the preference of [Mo8O26]4- to
direct crystn. of a one-dimensional
37
Syntheses and characterization of
Co(pydc)(H2O)2 and Ni(pydc)(H2O) (pydc = 3,5-pyridinedicarboxylate). Whitfield, Tabatha; Zheng, Li-Min; Wang,
Xiqu; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
The
hydrothermal reaction of 3,5-pyridinedicarboxylic acid (pydcH2) and Co(NO3)2 or
Ni(NO3)2 in the presence of 4,4'-bipyridine results in two novel compds.,
Co(pydc)(H2O)2 (1) and Ni(pydc)(H2O) (2), which were both characterized by x-ray
crystallog.
36
Syntheses and characterization of
Co2(4,4'-bipy)2(V4O12), Co(pz)(VO3)2 and Co2(2-pzc)(H2O)(VO3)3 (4,4'-bipy =
4,4'-bipyridine, pz = pyrazine, 2-pzc = 2-pyrazinecarboxylate). Zheng, Li-Min; Wang,
Xiqu; Wang, Yongsheng; Jacobson, Allan J.
Department
of Chemistry,
University of
Abstract
By
using different org. ligands, three new inorg.-org. hybrid compds. of Co V
oxide were synthesized hydrothermally: Co2(4,4'-bipy)2(V4O12) 1, Co(pz)(VO3)2 2
and Co2(2-pzc)(H2O)(VO3)3 3, where 4,4'-bipy = 4,4'-bipyridine, pz = pyrazine,
2-pzc = 2-pyrazinecarboxylate. Crystal
data: 1, triclinic, space group P.hivin.1, a 8.164(2), b 8.587(2), c 10.162(2)
.ANG., a
87.04(3), b 75.72(3), g 75.02(3)°; 2,
orthorhombic, space group Pnna, a 10.2793(8), b 11.5639(9), c 7.4822(6) .ANG.;
3, orthorhombic, space group Pna21, a 15.253(1), b 8.2554(7), c 10.6784(9)
.ANG.. Compd. 1 contains CoV2O6 layers
cross-linked by 4,4'-bipyridine ligands.
Compds. 2 and 3 are three-dimensional frameworks contg. both infinite
metavanadate chains and either Co(pz) or Co2(2-pzc) chains. The magnetic properties of 1-3 are reported.
35
Synthesis of large ZSM-5 crystals under
high pressure. Wang, Xiqu; Jacobson, Allan J. Department of Chemistry and Materials
Research Science and
Abstract
The
synthesis temp. for silicalite-I (MFI) can be raised to 300° by applying high
pressure to stabilize the structure-directing org. template. The elevated temp. and pressure favor the
formation of crystals with improved quality.
Prismatic silicalite-I crystals with a uniform size of .apprx.0.7 ´ 0.2 ´ 0.2 mm were
obtained by heating a gel prepd. from TMA-silicate soln., TPABr and Na
hexafluorosilicate at 250° under a pressure of 80 MPa. The influence of synthesis conditions on the
crystal sizes was studied by systematically changing temp., pressure and gel
compns. Under the specific conditions of
250°
and 80 MPa, a strong correlation was found between the crystal size and the
F/Si mole ratio of the starting gel, which enables the prepn. of uniform
crystals of silicalite-I with preset dimensions.
34
The novel open-framework vanadium
silicates
Abstract
The
open-framework vanadium silicates K2(VO)(Si4O10)×H2O (VSH-1) and
Cs2(VO)(Si6O14)×3H2O (VSH-2) were hydrothermally
prepd. The structures of both compds.
were detd. by single-crystal x-ray diffraction, and their compns. were measured
by electron microprobe anal.
33
Control of organic-inorganic framework
structures by tuning the organic ligand. Zheng, Li-Min; Wang, Xiqu; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
Strategies
for developing novel inorg.-org. hybrid compds. with a variety of functions
have been explored in recent years. Our studies
of the cobalt vanadate compds., by using, for example, 4,4'-bipyridine,
pyrazine and 2-pyrazinecarboxylate ligands, have resulted in several new
compds. with interesting structures.
These structures, ranging from two-dimensional layers to a three-dimensional
chiral open-framework, are found to be closely related to the size and
coordination capabilities of the org. ligands.
The magnetic and absorption properties have been investigated.
32
Hybrid coordination polymers-metal oxide
compounds with chiral structures. Zheng, Li-Min; Whitfield, Tabatha; Wang,
Xiqu; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
Using
an unsym. org. ligand, 2-pyrazinecarboxylate, three novel inorg.-org. hybrid
compds. were prepd., whose framework structures contain tubes formed from four
M(2-pzc) helical chains, namely [Co4(2-pzc)4(V6O17)].xH2O (I),
[Ni4(2-pzc)4(V6O17)].xH2O (II) and [(NH4)2Co8(2-pzc)8(H2O)2(VO3)10].xH2O
(III). I and II are chiral, whereas III
contains equal nos. of left- and right-handed tubes. I and II are tetragonal, space group I4, Z =
4, R = 0.0485 and 0.1032, resp., and III is monoclinic, space group Cc, Z = 4,
R = 0.0548. The pH of the syntheses
dets. the nature of the vanadate chains and consequently the final structure
that is adopted. The thermal stabilities
of I and II are among the highest of the metal-org. complexes reported. Further work is in progress to combine asym.
ligands with other inorg. oxide networks.
31
Hydrothermal Synthesis and
Abstract
The
new thioantimonates [(CH3NH3)0.5(NH4)1.5]Sb8S13×2.8H2O (1) and
Rb2Sb8S13×3.3H2O
(2) were hydrothermally synthesized and characterized by single-crystal
structure detn. The two compds. are
isostructural and crystallize in the monoclinic system, space group P21/m with
a 7.1931(3), b 25.770(1), c 15.9999(8) .ANG., b 96.856(1)°, Z = 4 for 1 and
a 7.1899(8), b 25.760(3), c 15.973(2) .ANG., b 96.541(2)°, Z = 4 for 2,
measured at 293 K. The structure consists
of 12-membered rings of SbS3 pyramids that are linked into 1-dimensional
complex chains. The chains are
interconnected by secondary Sb-S bonds to form puckered layers. The stacking of the layers aligns the
12-membered rings, giving rise to a system of wide channels with an aperture of
.apprx. 5.9´8.0 .ANG.. The monovalent cations and water mols. are
located in the channels. The layers are
closely related to those found in (C4H10N)2Sb8S13×0.15H2O and
(C8N4H26)0.5Sb7S11. (c) 2000 Academic
Press.
30
Hydrothermal synthesis and structures of
Ba3(NbO)2(PO4)4 and Co3(NbO)2(PO4)4(H2O)10.
Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. Department of Chemistry and
Materials Research Science and
Abstract
The
new niobium phosphates Ba3(NbO)2(PO4)4 (1) and Co3(NbO)2(PO4)4(H2O)10 (2) were
synthesized in single crystal form by hydrothermal reactions at 250° and 170° resp. The crystal structures were detd. from x-ray
diffraction data. Both compds. contain
NbP2O9 complex chains as a fundamental structural unit. The chains are similar to those of the known
compd. K3NbP2O9 and structurally may be considered similar to a slice of the
Zr(HPO4)2 layer in a-zirconium phosphate. In compd. 1 the chains are sepd. and are held
together by Ba-O bonds while in 2 the chains are linked by CoO6 octahedra to
form a framework structure.
29
Synthesis and crystal structures of
[H3N(CH2)2NH3]NbMOF(PO4)2(H2O)2, M = Fe,Co and
[H3N(CH2)2NH3]Ti(Fe0.9Cr0.1)(F1.3O0.7)(H0.3PO4)2(H2O)2. Wang, Xiqu; Liu,
Lumei; Cheng, Heidi; Ross, Kent; Jacobson, Allan J. Department of
Chemistry, University
of
Abstract
The
new niobium phosphates [H3N(CH2)2NH3]NbFeOF(PO4)2(H2O)2 and
[H3N(CH2)2NH3]NbCoOF(PO4)2(H2O)2 were synthesized in single crystal form by
hydrothermal reactions at 165°. The new phase
[H3N(CH2)2NH3]Ti(Fe0.9Cr0.1)(F1.3O0.7)(H0.3PO4)2(H2O)2 was obtained by hydrothermal
electrocrystn. at 170°.
The crystal structures were refined from x-ray diffraction data. They are structurally similar to the known
layered iron phosphate [H3N(CH2)2NH2][Fe2F2(HPO4)2(H2O)2] designated as ULM-10
and the mineral curetonite.
28
Synthesis and crystal structures of
yttrium sulfates Y(OH)(SO4), Y(SO4)F, YNi(OH)3(SO4)-II and Y2Cu(OH)3(SO4)2F×H2O. Wang, Xiqu; Liu, Lumei;
Ross, Kent; Jacobson, Allan J.
Department of Chemistry, University of
Abstract
Y(OH)(SO4),
Y(SO4)F, YNi(OH)3(SO4)-II and Y2Cu(OH)3(SO4)2F×H2O were obtained
from hydrothermal reactions at 380° under a pressure
of 210 MPa. Their crystal structures
were refined from single-crystal x-ray diffraction data. The four compds. have the following space
groups and unit cells: Y(OH)(SO4), P21/n, a 7.9498(6), b 10.9530(9), c
8.1447(6) .ANG., b 93.764(1)°; Y(SO4)F, Pnma,
a 8.3128(9), b 6.9255(7), c 6.3905(7) .ANG.; YNi(OH)3(SO4)-II, Pnma, a
6.9695(8), b 7.2615(8), c 10.292(1) .ANG.; Y2Cu(OH)3(SO4)2F×H2O, P21/n, a
11.6889(7), b 6.8660(4), c 12.5280(8) .ANG., b 97.092(1)°. The coordination environments of the yttrium
atoms in the four structures vary from highly irregular 6 + 2, 6 + 3, 7 + 1
coordination polyhedra to relatively regular dodecahedra.
27
Synthesis and single-crystal structures
of some new niobium phosphates. Jacobson, Allan J.; Wang, Xiqu; Liu, Lumei;
Cheng, Heidi. Department of Chemistry, University of
Abstract
We
are interested in direct incorporation of org. templates into layered compds.
by using hydrothermal synthesis. Here we
report the synthesis of several niobium phosphate compds. using reactions of
niobium metal, phosphoric acid and other cations in water in the presence of
NH4HF2. The compd. [NbOPO4]4
(H3NCH2COOH)2(H2PO4)(OH,F) comprising niobium phosphate layers and interlayer
glycininium phosphate ions is one example.
The structure of this phase was detd. from single crystal X-ray
diffraction data. Results for other
phases prepd. by the same general technique will be described.
26
Two- and three-dimensional mixed-valence
Cu(I)-Cu(II) coordination polymers: syntheses and characterization of a-, b-[Cu2X(C5H3N2O2)2(H2O)]
(X = Cl, Br). Zheng, Li-Min; Wang, Xiqu; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
Novel
mixed valence compds. with the formula a-[Cu2X(C5H3N2O2)2(H2O)]n
[X = Cl (1), Br (3), C5H3N2O2 = 2-pyrazinecarboxylate] and their isomers b-[Cu2X(C5H3N2O2)2(H2O)]n
[X = Cl (2), Br (4)] were synthesized and structurally characterized. Crystal data: 1, orthorhombic, space group
Pbca, a 12.8040(7), b 7.7323(4), c 26.104(1) .ANG., V = 2584.4(2) .ANG.3, Z =
8, R1 = 0.0559; 2, triclinic, P.hivin.1, a 6.1908(7), b 7.7246(8), c 13.968(2)
.ANG., a
78.853(2), b 81.455(2), g 78.036(2)°, Z = 2, R1 =
0.0592; 3, orthorhombic, space group Pbca, a 12.7082(6), b 7.7676(4), c
26.1548(12) .ANG., Z = 8, R1 = 0.0257; 4, triclinic, P.hivin.1, a 6.2462(5), b
7.7568(6), c 14.1121(10) .ANG., a 78.082(1), b 81.702(1), g 79.096(1)°, Z = 2, R1 =
0.0290. The a-isomers 1 and 3
have two-dimensional layer structures which are composed of mixed valence
chains of [CuICuII(C5H3N2O2)2(H2O)] and chains of corner-sharing
25
A three-dimensional coordination polymer
with an expanded NbO structure. Niu, Tianyan; Wang, Xiqu; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
The
first three-dimensional cyanometalate with an expanded NbO-type structure,
[(Ph3Sn)2Ni(CN)4×Ph3SnOH×0.8MeCN×0.2H2O] (1), was
prepd. by slow interdiffusion Ph3SnCl in MeCN and
24
Abstract
ETS-10
crystals up to 45 mm in size were synthesized at 240° under a pressure
of 80 MPa and the structure refined from single crystal x-ray diffraction
data. Titanosilicate ETS-10 is
tetragonal, space group I41/amd, a 7.481(1), c 27.407(5) .ANG., R = 0.119 for
426 reflections. The framework structure
is described.
23
Electrochemical-hydrothermal synthesis
and structure of [N(CH3)4]2[Co(H2O)4V12O28].
Wang, Xiqu; Liu, Lumei;
Jacobson, Allan J.; Ross, Kent.
Department of Chemistry, University of
Abstract
Electrochem.
oxidn. of a vanadium electrode under hydrothermal conditions in the presence of
tetramethylammonium and cobalt ions gives [NMe4]2[Co(H2O)4V12O28].
22
Electrochemical-hydrothermal synthesis of
vanadium oxide materials. Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
Hydrothermal
synthesis, in which one component is electrochem. generated, can provide addnl.
control of the reaction chem. Several
novel vanadium oxides have been synthesized with this technique by anodizing
vanadium metal in aq. solns. at mild temps.
The new compd. Zn2(OH)VO4 contains both 5- and 6-coordinated Zn and has
a centrosym. structure. The
centrosymmetry is broken in the nickel analog Ni2(OH)VO4 due to Jahn-Teller
distortions. Using tetramethylammonium
as a template the novel compd. [N(CH3)4]2[Co(H2O)4V12O28] has been
obtained. The structure contains
mixed-valent vanadium oxide layers that are cross-linked into a porous
framework by CoO6 octahedra. The channel-like
voids of the framework are filled by N(CH3)4 cations. This compd. is closely related to the known
vanadium oxides [N(CH3)4]V3O14, [C6H14N2]V6O14.sum.H2O and [(en)2Cu]V6O14].
21
Influence of reaction conditions on the
electrochemical-hydrothermal synthesis of two ammonium vanadium phosphates:
(NH4)2VO(HPO4)2×H2O and (NH4)2VO(V0.88P1.12)O7. Liu, Lumei; Wang, Xiqu;
Bontchev, Ranko; Ross, Kent; Jacobson, Allan J. Department of Chemistry, University of
Abstract
The
new phase (NH4)2VO(HPO4)2×H2O (I) has been synthesized by hydrothermal
electrocrystn. at 100°.
I is triclinic, space group P1 with Z=2, a=7.2499(8), b=8.1244(9),
c=8.6529(9) .ANG., a=73.472(2), b=80.085(2), g=85.077(2)° and V=480.94(9)
.ANG.3. When the reaction temp. is
increased to 110 °, I is completely transformed into the
known compd. (NH4)2VO(V0.88P1.12)O7 (II).
The layered compd. NH4VOPO4×xH2O (III), a new
example of the well-known MxVOPO4×xH2O phase has
also been prepd. by the same technique.
20
Synthesis and Structures of
Yttrium-Transition Metal Sulfates YM(OH)3(SO4), M = Ni, Cu. Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
YCu(OH)3(SO4)
and YNi(OH)3(SO4)-I were synthesized hydrothermally at 380° at a pressure of
210 MPa. YCu(OH)3(SO4) crystallizes in the
space group Pnma with a 13.956(1), b 6.1349(5) .ANG. , and c 6.3528(5)
.ANG.. YNi(OH)3(SO4)-I crystallizes in
the space group P212121 with a 13.335(1), b 6.1256(5), and c 6.4830(5) .ANG.. The two structures are topol. the same. Different distortions of the CuO6 and NiO6
octahedra account for the absence of a center of symmetry in
YNi(OH)3(SO4)-I. Both compds. decomp. to
form the oxides Y2M2O5 when heated to 980-1000° in air. (c) 1999 Academic Press.
19
The synthesis and single crystal
structure of an amino acid intercalated layered niobium phosphate:
[(NbOPO4)4.bul.(H3NCH2CO2H)2][H2PO4][OH, F].
Wang, Xiqu; Liu, Lumei; Cheng, Heidi;
Jacobson, Allan J. Department of
Chemistry and Materials Research Science and
Abstract
Niobium
phosphate contg. interlayer glycinium phosphate was synthesized hydrothermally
and its structure detd. from single crystal x-ray diffraction data. The crystal structure consists of NbOPO4
layers bridged by carboxylic groups of the glycinium H3NCH2CO2H cations with
H2PO4, F, and OH anions located in the interlayer spaces.
18
Abstract
The
compd. NH4[V2P2BO10(OH)2].1.5H2O has been synthesized by hydrothermal reaction
of V2O3, (NH4)2HPO4 and H3BO3 in aq. soln. at 190°C for 3 days
under autogeneous pressure. Transparent
blue crystals up to 0.3 mm in size were obtained. The structure has been solved by single
crystal methods, S.G. R-3m (#166), a0 = 14.116(2) .ANG., a = 71.96(2)°, R1 = 0.07. The structure consists of two edge sharing
V2O6 dimers which are linked together by sharing common corners with
[BP2O6(OH)2]2- trimers, thus forming 12-membered rings. These rings are arranged in doughnut-like
clusters which are centered by one of the templating NH4+ ions. The rest of NH4+ cations and the water mols.
are bonded to the lattice oxygens and to each other by an extended network of
hydrogen bonds which hold the whole complex structure together. The chem. compn. and thermal behavior of the
title compd. have been confirmed by microprobe SEM, IR and TGA analyses. Magnetic susceptibility studies revealed that
vanadium atoms in the V2O6 dimers are antiferromagnetically coupled.
17
Electrochemical-hydrothermal synthesis
and structural characterization of Zn2(OH)VO4. Wang, Xiqu; Liu,
Lumei; Jacobson, Allan J. Dep.
Chem., Univ. Houston, Houston,
TX, USA. Zeitschrift fuer Anorganische und
Allgemeine Chemie (1998), 624(12),
1977-1981. CODEN:
ZAACAB ISSN: 0044-2313. Journal
written in English. CAN
130:162180 AN 1999:43895.
Abstract
A
new Zn vanadate Zn2(OH)VO4 was synthesized by an electrochem.-hydrothermal
method and characterized by single crystal x-ray diffraction. The compd. crystallizes in the orthorhombic
system, space group Pnma, a = 14.645(1), b = 6.0215(5), c = 8.8757(8) .ANG., V
= 782.7(1) .ANG.3, Z = 4, rc = 4.459 g/cm3, m(MoKa) = 14.4 mm-1, T
= 223 K, 997 independent reflections, 95 refined parameters, R1 = 0.0339, wR2 =
0.0650 (I > 2s(I)).
In the structure, rutile-type [ZnO6] octahedral chains are
interconnected by [VO4] tetrahedra to form a framework of compn. [Zn(OH)VO4],
the voids of which are filled by Zn cations with trigonal bipyramidal and
octahedral coordination. The structure
is closely related to that of the adamite type phases and the minerals
descloizite PbZn(OH)VO4 and tsumcorite Pb0.5Zn(H2O)AsO4.
16
Electrochemical-hydrothermal synthesis
and structure determination of a novel layered mixed-valence oxide: BaV7O16×nH2O. Wang, Xiqu; Liu, Lumei; Jacobson, Allan
J. Department of Chemistry, University of
Abstract
The
electrochem.-hydrothermal synthesis of a new mixed-valence oxide BaV7O16×nH2O (n » 4.4) with
[V7O16] layers contg. both V O tetrahedra and distorted octahedra is reported.
15
Heteropolyanions with transition metal
cores: Some new host-guest systems of polyvanadomolybdates. Wang, Xiqu; Do, Junghwan; Woods, LeVar;
Jacobson, Allan J. Department
Chemistry, University
Abstract
Hydrothermal
syntheses in the system V2O5 -MoO3 -TMAOH at systematically varied pH values
led to several novel polyvanadomolybdates that were characterized by IR, TGA, electron
microprobe anal. and single crystal structure detns. The anions of
(TMA)6[(VO4)2(Mo18O54)].sum..apprx.3H2O(1) have the Wells-Dawson cluster
structure. Both VO4 tetrahedra inside
the Mo18O54 shell are ordered. Because
of the larger size of the vanadium cations the interactions between the oxygen
atoms of the guest VO4 tetrahedra and Mo atoms of the shell are stronger than
those in the Wells-Dawson cluster [(PO4)2(Mo18O54]6-. The anion clusters in the new compds. of
(TMA)4[(VO4)(V3.9Mo10.1O38)] .sum..apprx.4H2O(2) and
(TMA)8[(MoO4)-(V21.4Mo0.6O54)].sum.6H2O(3) are isotypic to those in the known
compds. (CN3H6)8H(
14
Hydrothermal synthesis and structures of
two tetramethyl-ammonium iron molybdates.
Do, Junghwan; Wang, Xiqu; Jacobson, Allan
J. Department Chemistry, University
Abstract
Two
new compds. (TMA)2FeMo6O20 and [TMA]2[Fe(H2O)6]Mo8O26 have been synthesized
through hydrothermal reactions.
(TMA)2FeMo6O20 crystallizes in the monoclinic space group C2/m; a = 21.204(1).ANG.,
b = 7.6393(5).ANG., c = 8.4191(6).ANG., b = 104.602(1)°, V =
1319.7(2).ANG.3, Z = 2.
[TMA]2[Fe(H2O)6]Mo8O26 crystallizes in the space group P21/n; a =
10.3945(5).ANG., b = 16.4103(8).ANG., c = 10.8935(5).ANG., b = 98.842(1)°, V = 1836.1(2).ANG.3,
Z = 2. The crystal structure of
(TMA)2FeMo6O20 consists of [FeMo6O202-] layers sepd. by a layer of tetra-Me
ammonium cations. The layers are built
up from anionic chains, [Mo6O204-] of corner- and edge-sharing MoO6 octahedra
with compn. [FeMo6O20]. The arrangement
of MoO6 octahedra in the chains is identical to that found in the red potassium
molybdenum bronze structure. In the
(TMA)2FeMo6O20 structure, the chains are connected into layers by bridging FeO6
octahedra. In the bronze structure the chains
are directly connected by sharing oxygen atoms.
The structure of [TMA]2[Fe(H2O)6]Mo8O26 is made up by packing an
octahedral [Fe(H2O)62+] cation and a typical b-[Mo8O264-]
cluster anion.
13
Syntheses and Structural Characterizations
of Two Three-Dimensional Polymers: ¥3[
Abstract
The
three-dimensional coordination polymers [
12
Synthesis and crystal structure of a
tin-nickel-cyanide 3D coordination polymer.
Niu, Tianyan; Korp, James D.; Wang, Xiqu;
Jacobson, Allan J. Department
chemistry, University
Houston,
Abstract
In
the studies of open framework structures with low framework densities, we
synthesized and structurally characterized a coordination polymer
[(C6H5)3Sn]2Ni(CN)4.sum.(C6H5)3SnCl-.sum.CH3CN which is topol. related to the
structure of NbO. The three dimensional
neutral framework is built up from square planar Ni(CN)42- anions and bridging
(C6H5)3Sn+ cations that are connected in such a way that large voids are
generated. The compd. was prepd. in
single crystal form by slow interdiffusion of soln. of (C6H5)3SnCl and
K2Ni(CN)4 and the structure was solved by single crystal X-ray
diffraction. The central cavity is the
largest known in this class of materials.
As synthesized, the cavity in the structure is filled by (C6H5)3SnCl and
acetonitrile mols. that support the framework.
More details about the synthesis and structure will be presented.
11
Hydrothermal synthesis and crystal
structure of [(CH3NH3)1.03K2.97]Sb12S20.1.34H2O. Wang, Xiqu; Jacobson, Allan J.; Liebau,
Friedrich. Department of Chemistry, University of
Abstract
A
novel thioantimonate(III) [(CH3NH3)1.03K2.97]Sb12S20×1.34H2O was
synthesized hydrothermally. It
crystallizes in space group P.hivin.1, with a 11.9939(7), b 12.8790(8), c
14.9695(9) .ANG., a 100.033(1), b 99.691(1), g 108.582(1)°, Z = 2 and R =
0.037. In the crystal, each Sb(III)
atoms has short bonds (2.37-2.58 .ANG.) to three S atoms. The pyramidal [SbS3] groups share common S
atoms forming two types of centrosym. [Sb12S20] rings with the same topol.
which are interconnected by weaker Sb-S bonds (2.92-3.29 .ANG.) into
2-dimensional layers. Adjacent layers
are parallel with K+, CH3NH3+, and H2O mols. located between them. Variation of bond valence sums calcd. for the
Sb(III) cations is correlated with the coordination geometry. This is interpreted as due to the stereochem.
activity of their lone electron pairs.
(c) 1998 Academic Press.
10
Synthesis and crystal structure of
Sr10[Sb7O13(OH)]2[SbSe3]2Se×2H2O. Wang, Xiqu; Jacobson, Allan J. Department of Chemistry, University of
Abstract
A
new Sr oxoselenoantimonate(III), Sr10[Sb7O13(OH)]2 [SbSe3]2Se×2H2O, was
hydrothermally synthesized and characterized by single crystal structure
detn. It crystallizes in the monoclinic
system, space group P21/n, with a 11.4013(6), b 18.417(1), c 13.0568(7) .ANG., b 108.51(1)°, measured at 223
K. In the structure [SbO3] pyramids
share O atoms to form [Sb7O13(OH)] single branched six-rings that are
interconnected by Sr-O bonds into layers [Sr5Sb7O13(OH)]. The interlayer spaces are occupied by [SbSe3]
pyramids and isolated Se2- anions. Both
the [Sb7O13(OH)] single branched six-rings and the [SbSe3] pyramids can be
considered as building blocks of the known structure K6[Sb12O18][SbSe3]2×6H2O. (c) 1998 Academic Press.
9
An investigation of microporous cetineite-type
phases A6[B12O18][CX3]2[Dx(H2O,OH,O)6-y]. Part 2. Crystal structures of
cetineites, A6[Sb12O18][SbX3]2[DxY6-y], and their changes with chemical
composition. Wang, X.; Liebau,
F.. Inst. Geowiss, Univ. Kiel,
Kiel, Germany. Zeitschrift fuer Kristallographie (1999),
214(12), 820-834. CODEN: ZEKRDZ
ISSN: 0044-2968. Journal written in English. CAN 132:341381 AN 1999:794714.
Abstract
The
cetineite structure-type has the very general formula A6[B12O18][CX3]2[DxY6-y]
with 0 £
x £
2 and 0 £
y £
6. In a preceding paper natural and
synthetic cetineite-type phases with a = Na+, K+, Rb+, Sr2+, Ba2+; B = C = Sb;
X = S2-, Se2-; D = Na+, Sb3+, C4+; and Y = H2O, OH-, O-2 were described. The results of crystal structure detns. from
single-crystal x-ray diffraction data of 4 of these phases are reported. K6[Sb12O18][SbS3]2[Sb0.12(H2O)5.64(OH)0.36]:
space group P63/m, a 14.318(3), c 5.633(1) .ANG., Z = 1;
Sr6[Sb12O18][SbSe3]2[(OH)6]: space group P63/m, a 14.320(3), c 5.515(1) .ANG.,
Z = 1; Ba6[Sb12O18][SbSe3]2[(CO3)1.5O1.5]: P63/m, a 14.504(3), c 5.616(1)
.ANG., Z = 1; K6[Sb12O18][SbSe3]2[(H2O)6]: P63, a 29.260(7), c 5.6164(7) .ANG.,
Z = 4. At. coordinates and R's are
given. In the 1st 3 phases 1-dimensional
stacks of trigonal pyramids [SbX3]3- are orientationally disordered between
[Sb12O18] tubes stretching along [001].
Rotation of the tubes around their axes is governed by repulsive forces
between lone-electron pairs of the Sb3+ of neighboring tubes. The 4th phase has a 2a, 2b, c superstructure
with an ordered arrangement of the stacks of [SbSe3] pyramids. Comparison of these 4 cetineite-type
structures, with others described in the literature, reveal that the reported
existence of subtypes with ordered and disordered [SbX3] groups in a, b, c unit
cells of P63 symmetry is doubtful.
Changes in the structures are correlated with the length of the A-X
bonds, the valence of the A cations, and the occupancy and size of the D
cations, which are located along the tube axes and surrounded by Y ligands that
form slightly elongated trigonal antiprisms.
The extension of the cetineite structure field, r(B) = r(C) = 0.76 .ANG.
(Sb3+), 1.84 .ANG. £ r(X) £ 1.98 .ANG. (S2-
and Se2-), 1.02 .ANG. £ r(A[6]) £ 1.52 .ANG. (Na+
to Rb+), and valence of a equal to +1 and +2, is correlated with the strength
and covalency of the various bonds between the atoms.
8
An investigation of microporous
cetineite-type phases A6[B12O18][CX3]2[Dx(H2O,OH,O)6-y]. I. The cetineite
structure field. Wang, X.; Liebau, F.. Mineralogisches Institut der Universitat
Abstract
Hydrothermal
syntheses between 120 and 200° were performed
to det. the chem. variability of semiconducting microporous materials with
cetineite structure. The syntheses were
based on the general formula A6[B12O18][CX3]2[Dx(H2O,OH,O)6-y], (0 £ x £ 2; 0 £ y £ 6), which was
derived from x-ray crystal structure refinements. A = Li+, Na+, K+, Rb+, Cs+, Tl+, NH4+, Ca2+,
Sr2+, and Ba2+ were introduced as hydroxides, in some cases as carbonates, B =
C = As3+, Sb3+, and Bi3+, and X = S2-, Se2-, and Te2- as elements. Only syntheses with B = C = Sb3+ and X = S2-
and Se2- were successful. Known
cetineite-type phases now include the element combinations A/Sb3+/S2- with A =
Na+ and K+, and A/Sb3+/Se2- with A = Na+, K+, Rb+, Sr2+, Ba2+, and probably
Tl+. Variable amts. of Na+, Sb3+ and C4+
occupy the D position of the cetineite-type structure. The chem. variability can be described by the
coupled substitutions A+ + H2O .tautm. A2+ + OH-, mH2O
.tautm. Dm+ + mOH-, and nOH- .tautm. Dn+ + nO2-. The
crystals obtained are orange to dark red, in agreement with their
semiconducting properties.
7
Electronic structure of a novel class of
nanoporous materials. Starrost, F.;
Krasovskii, E. E.; Schattke, W.; Jockel, J.; Simon, U.; Wang, X.; Liebau,
F.. Inst. Theoretische Physik, Christian-Albrechts-Univ. Kiel, Kiel,
Germany. Physical Review
Letters (1998), 80(15),
3316-3319. CODEN: PRLTAO ISSN: 0031-9007. Journal
written in English. CAN
129:8775 AN 1998:270111.
Abstract
The
electronic structures of crystals from the cetineite family, promising new
nanoporous materials, are theor. investigated for the first time on an ab
initio basis. The trend exptl. obsd. in
the optical gaps' dependence on the chem. compn. is explained.
6
K3Sb7IIIO9Se3.3H2O: the first crystalline
nanoporous material with a photo-semiconducting host structure. Simon, Ulrich;
Schuth, Ferdi; Schunk, Stephan; Wang, Xiqu; Liebau, Friedrich. Inst. Anorg. Chem., Univ. Gesamthochsch., Essen,
Germany. Angewandte Chemie, International Edition in
English (1997), 36(10),
1121-1124. CODEN:
ACIEAY ISSN: 0570-0833. Journal
written in English. CAN
127:75006 AN 1997:380232.
Abstract
Cryst.,
template-free K3Sb7IIIO9Se3.3H2O (1) with a host structure consisting of
one-dimensional tubular chains was prepd. and its thermal, optical and elec.
properties were discussed.
5
Influence of lone-pair electrons of
cations on bond-valence parameters. Wang, X.; Liebau, F..
Mineralogisches Inst., Univ.
Kiel, Kiel, Germany.
Zeitschrift fuer Kristallographie
(1996), 211(7), 437-9.
CODEN: ZEKRDZ ISSN:
0044-2968. Journal written in English. CAN 125:177749 AN 1996:417705.
Abstract
According
to the current bond-valence concept, the valence Vi of an atom Ai is a function
of the distances Dij to its neighbors Xj and can be calcd. using Vi = .sum.sij
= .sum.exp[(r0 - Dij)/0.37], where the bond-valence parameter r0 is considered
to be const. for each element pair A-X.
A statistical anal. based on 1924 [LMm] polyhedra is presented, where L
are cations having 1 lone-pair and X = O, S, or Se. According to this anal.,forir0 for each
individual [LXm] polyhedron is dependent on the stereochem. influence of the
lone-pair electrons on the geometry of the polyhedron. This influence is expressed by a vector
.vector.Fi
= .vector.F(ÐXj - Li - Xj',
Dij). As a result, the formal
bond-valence sum for an individual lone-pair cation Li can be calcd. with
.sum.jsij = .sum.jexp[(E|.vector.F| + F -
Dij)/0.37] where E and F are consts.
4
Studies on bond and atomic valences. I.
Correlation between bond valence and bond angles in SbIII chalcogen compounds:
the influence of lone-electron pairs. Wang, Xiqu; Liebau, Friedrich. Mineralogisches Inst., Univ. Kiel,
Kiel, Germany. Acta Crystallographica, Section B:
Structural Science (1996), B52(1),
7-15. CODEN: ASBSDK ISSN: 0108-7681. Journal
written in English. CAN
124:242839 AN 1996:145657.
Abstract
In
the present bond-valence concept the bond-valence parameter ro is treated as const.
for a given pair of atoms; it is assumed that the bond valence sij is a
function of the corresponding bond length Dij, and that the at. valence is an
integer equal to the formal oxidn. no. forVi derived from stoichiometry. However, from a statistical anal. of 76
[SbIIISn] and 14 [SbIIISen] polyhedra in exptl. detd. structures, it is shown
that for SbIII-X bonds (X = S, Se), ro is correlated with ai, the av. of the
X-Sb-X angles between the three shortest Sb-X bonds. This is interpreted as a consequence of a
progressive retraction of the 5s lone-electron pair from the SbIII nucleus,
which can be considered as continuous change of the actual at. valence actVi of
Sb from +3 towards +5. A procedure is
derived to calc. an effective at. valence effVi of SbIII from the geometry, ai and Dij, of the
[SbIIIXn] polyhedra, which approximates actVi and is a better description of
the actual valence state of SbIII than the formal valence forVi. Calcd. effVSb are found to vary between +2.88
and +3.80 v.u. for [SbIIISn] and between +2.98 and +3.88 v.u. for [SbIIISen]
polyhedra. A corresponding modification
of the present bond-valence concept is also required for other cations with
lone-electron pairs.
3
Synthesis and crystal structure of a new
microporous thioantimonate(III) [H3N(CH2)3NH3]Sb10S16. Wang, Xiqu.
Mineralogisches Inst.,
Universitaet Kiel,
Abstract
[H3N(CH2)3NH3]Sb10S16
was hydrothermally synthesized from elemental Sb and S using H2N(CH2)3NH2 as a
templating agent. The dark red crystals
are monoclinic, space group P21/n, a 18.359(4), b 10.927(2), c 17.389(3) .ANG.,
b
111.44(2)°,
Z = 4. The structure was refined to R(F)
= 0.071 with 3210 independent single crystal x-ray reflections (MoKa radiation) and
for 256 variables. [SbS4] and [SbS5]
polyhedra share corners and edges to form a 3-dimensional framework which is
traversed by a 2-dimensional channel system.
The [H3N(CH2)3NH3]2+ cations are located within cages at intersections
of the channels.
2
Synthesis and structure of
[CH3NH3]2Sb8S13: a nanoporous thioantimonate(III) with a two-dimensional
channel system. Wang, Xiqu; Liebau,
Friedrich. Mineralogisches
Institut, Universitaet Kiel, Kiel,
Germany. Journal of
Abstract
[MeNH3]2Sb8S13
was synthesized as dark-red plate-like crystals by heating Sb and S with an aq.
soln. of MeNH2 between 130 and 190°. It is triclinic, space group P.hivin.1, with
a 15.866(3), b 11.581(2), c 8.295(2) .ANG., a 71.46(2), b 75.71(2), g 82.25(2)°, and Z = 2. The structure was detd. and refined with 3342
independent single crystal x-ray reflections (235 parameters, R = 0.061, Rw =
0.052). Each Sb atom forms three short bonds
to S reflecting the influence of a lone electron pair. Of the eight nonequivalent Sb atoms, three
have one longer bond and four other Sb atoms have two longer bonds to S. The [SbSn] polyhedra share corners and edges
to form a three-dimensional framework.
This framework is traversed by a system of two types of intersecting
channels parallel to [010] and [001].
[MeNH3]+ cations located in the channel intersections are orientationally
disordered; those in pockets of the [010] channels are ordered.
1
A new method for determining the
alkalinity of igneous rock series. Wang, Xiqu.
Abstract
A
new method for distinguishing the 3 major petrogenetic series of igneous rocks
(subalkaline, alk., and strongly alk. series) is proposed, based on examn. of
the behavior of major rock-forming oxides.
During fractional crystn., SiO2 first combines with MgO and CaO to form
forsterite, diopside, enstatite, etc. and the sepn. of these minerals doesn't
change the alky. of the magma very much.
In the diopside and enstatite, the amt. of SiO2 is approx. equal to CaO
+ 1.5MgO, in wt.%. Hence, the relative
proportion of (SiO2-CaO-1.5MgO) wt.% with alkali metals in rocks can be used to
est. the alky. of rock series.
Boundaries among subalk. series, alk. series and strongly alk. series
are presented in a (SiO2-CaO-MgO) wt.% vs. (K2O + 1.5Na2O) wt.% diagram, based
on 263 groups of rock compn. data. The
new method is more accurate than the SiO2 vs. (K2O + Na2O) diagram given by A.
Miyashiro (1978) and G. MacDonald and T. Katsura, (1964), esp. for the rocks with
very high or very low SiO2 content.