Structural influences of organonitrogen ligands on vanadium oxide solids. Hydrothermal syntheses and structures of the terpyridine vanadates [V2O4(terpy)2]3[V10O28], [VO2(terpy)][V4O10], and [V9O22(terpy)3

Hydrothermal reactions of the V2O5/2,2':6':2"-terpyridine/ZnO/H2O system under a variety of conditions yielded the organic-inorganic hybrid materials [V2O4(terpy)2]3[V10O28].2H2O (VOXI-10), [VO2(terpy)][V4O10] (VOXI-11), and [V9O22(terpy)3] (VOXI-12). The structure of VOXI-10 consists of discrete binuclear cations [V2O4(terpy)2]2+ and one-dimensional chains [V10O28]6-, constructed of cyclic [V4O12]4- clusters linked through (VO4) tetrahedra. In contrast, the structure of VOXI-11 exhibits discrete mononuclear cations [VO2(terpy)]1+ and a two-dimensional vanadium oxide network, [V4O10]1-. The structure of the oxide layer is constructed from ribbons of edge-sharing square pyramids; adjacent ribbons are connected through corner-sharing interactions into the two-dimensional architecture. VOXI-12 is also a network structure; however, in this case the terpy ligand is incorporated into the two-dimensional oxide network whose unique structure is constructed from cyclic [V6O18]6- clusters and linear (V3O5(terpy)3) moieties of corner-sharing vanadium octahedra. The rings form chains through corner-sharing linkages; adjacent chains are connected through the trinuclear units. Crystal data: VOXI-10, C90H70N18O42V16, triclinic P1, a = 12.2071(7) A, b = 13.8855(8) A, 16.9832(10) A, alpha = 69.584(1) degrees, beta = 71.204(1) degrees, gamma = 84.640(1) degrees, Z = 1; VOXI-11, C15H11N3O12V5, monoclinic, P2(1)/n, a = 7.7771(1) A, b = 10.3595(2) A, c = 25.715(4) A, beta = 92.286(1) degrees, Z = 4; VOXI-12, C45H33N9O22V9, monoclinic C2/c, a = 23.774(2) A, b = 9.4309(6) A, c = 25.380(2) A, beta = 112.047(1) degrees, Z = 4.     

A hydrothermal investigation of the 1/2V2O5-H2C2O4/H3PO4/NH4OH system: synthesis and structures of (NH4)VOPO(4).1.5H2O, (NH4)0.5VOPO(4).1.5H2O, (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2](2).3H2O, and (NH4)2[VO(HPO4)]2(C2O4).5H2O

The 1/2V2O5-H2C2O4/H3PO4/NH4OH system was investigated using hydrothermal techniques. Four new phases, (NH4)VOPO(4).1.5H2O (1), (NH4)0.5VOPO(4).1.5H2O (2), (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2.3H2O (3), and (NH4)2[VO(HPO4)]2(C2O4).H2O (4), have been prepared and structurally characterized. Compounds 1 and 2 have layered structures closely related to VOPO(4).2H2O and A0.5VOPO4.yH2O (A = mono- or divalent metals), whereas 3 has a 3D open-framework structure. Compound 4 has a layered structure and contains both oxalate and phosphate anions coordinated to vanadium cations. Crystal data: (NH4)VOPO(4).1.5H2O, tetragonal (I), space group I4/mmm (No. 139), a = 6.3160(5) A, c = 13.540(2) A, Z = 4; (NH4)0.5VOPO(4).1.5H2O, monoclinic, space group P2(1)/m (No. 11), a = 6.9669(6) A, b = 17.663(2) A, c = 8.9304(8) A, beta = 105.347(1) degrees, Z = 8; (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2.3H2O, triclinic, space group P1 (No. 2), a = 10.2523(9) A, b = 12.263(1) A, c = 12.362(1) A, alpha = 69.041(2) degrees, beta = 65.653(2) degrees, gamma = 87.789(2) degrees, Z = 2; (NH4)2[VO(HPO4)]2(C2O4).5H2O, monoclinic (C), space group C2/m (No. 12), a = 17.735(2) A, b = 6.4180(6) A, c = 22.839(2) A, beta = 102.017(2) degrees, Z = 6.     

Structure and properties of the thorium vanadyl tellurate, Th(VO2)2(TeO6)(H2O)2

The hydrothermal reaction of Th(NO3)4.xH2O with V2O5 and H6TeO6 at 200 degrees C under autogenously generated pressure results in the formation of Th(VO2)2(TeO6)(H2O)2 as a pure phase. The single-crystal X-ray data indicate that Th(VO2)2(TeO6)(H2O)2 possesses a three-dimensional structure constructed from ThO9 tricapped trigonal prisms, VO5 distorted square pyramids, VO4 distorted tetrahedra, and TeO6 distorted octahedra. Both of the vanadium polyhedra contain VO2+ vanadyl units with two short V=O bond distances. The tellurate octahedron is tetragonally distorted and utilizes all of its oxygen atoms to bond to adjacent metal centers, sharing edges with ThO9 and VO5 units, and corners with two ThO9, one VO5, and two VO4 polyhedra. Crystallographic data: Th(VO2)2(TeO6)(H2O)2, orthorhombic, space group Pbca, a = 12.6921(7), b = 11.5593(7), c = 13.0950(8) A, Z = 8 (T = 193 K). The UV-vis diffuse reflectance spectrum of Th(VO2)2(TeO6)(H2O)2 shows vanadyl-based charge-transfer absorption features. Th(VO2)2(TeO6)(H2O)2 decomposes primarily to Th(VO3)4 when heated at 600 degrees C in air.     

Crystal structure and spectroscopic properties of Na(2)K(6)(VO)(2)(SO(4))(7)

Red-brown crystals of a new mixed alkali oxo sulfato vanadium(V) compound Na(2)K(6)(VO)(2)(SO(4))(7), suitable for X-ray determination, have been obtained from the catalytically important binary molten salt system M(2)S(2)O(7)-V(2)O(5) (M = 80% K and 20% Na). By slow cooling of a mixture with the mole fraction X(V(2)O(5)) = 0.24 from 325 degrees C, i.e., just below the liquidus temperature, to the solidus temperature of around 300 degrees C, a dark reddish amorphous phase was obtained containing crystals of the earlier described V(V)-V(IV) mixed valence compound K(6)(VO)(4)(SO(4))(8) and Na(2)K(6)(VO)(2)(SO(4))(7) described here. This compound crystallizes in the tetragonal space group P4(3)2(1)2 (No. 96) with a = 9.540(3) A, c = 29.551(5) A at 20 degrees C and Z = 4. It contains a distorted VO(6) octahedron with a short V-O bond of 1.552(6) A, a long one of 2.276(5) A trans to this, and four equatorial V-O bonds in the range 1.881(6)-1.960(6) A. The deformation of the VO(6) octahedron is less pronounced compared to that of the known oxo sulfato V(V) compounds. Each VO(3+) group is coordinated to five sulfate groups of which two are unidentately coordinated and three are bidentate bridging to neighboring VO(3+) groups. The length of the S-O bonds in the S-O-V bridges of the two unidentately coordinated sulfato groups are 1.551(6) A and 1.568(6) A, respectively, which are unusually long compared to our earlier measurements of sulfate groups in other V(III), V(IV), and V(V) compounds.     

Evolution of the structural chemistry of vanadium organodiphosphonate networks and frameworks: structural consequences of fluoride incorporation in the development of stable phases with void channels

Hydrothermal reactions of solutions containing a vanadate source, an organodiphosphonate, an organonitrogen component, and HF (V/P/O/F) yield a series of oxyfluorovanadium-diphosphonates with charge-compensation provided by organoammonium cations or hydronium cations. While V/P/O/F networks provide the recurrent structural motif, the linkage between the layers and the details of the polyhedral connectivities within the layers are quite distinct for the five structures of this study. [H2pip][V4F4O2(H2O)2{O3P(CH2)3PO3}2] (1) (pip = piperazine) is a conventional three-dimensional (3D) "pillared" layer structure, whose V/P/O/F networks are buttressed by the propylene chains of the diphosphonate ligands. In contrast, [H2en][V2O2F2(H2O)2{O3P(CH2)4PO3}] (2) and [H2en]2[V6F12(H2O)2{O3P(CH2)5PO3}2 {HO3P(CH2)5PO3H}] (3) are two-dimensional (2D) slablike structures constructed of pairs of V/P/O/F networks sandwiching the pillaring organic tethers of the diphosphonate ligands. Despite the common overall topology, the layer substructures are quite different: isolated {VO5F} octahedra in 2 and chains of corner-sharing {VO(3)F(3)} octahedra in 3. The 3D structure of [H2en]2[V7O6F4(H2O)2{O3P(CH2)2PO3}4].7H2O (4.7H2O) exhibits a layer substructure that contains the ethylene bridges of the diphosphonate ligands and are linked through corner-sharing octahedral {VO6} sites. The connectivity requirements provide large channels that enclose readily removed water of crystallization. The structure of [H3O][V3F2(H2O)2{O3P(CH2)2PO3}2].3.5H2O (5.3.5H2O) is also 3D. Because of the similiarity with 4.7H2O, it exhibits V/P/O/F layers that include the organic tethers of the diphosphonates and are linked through corner-sharing {VO6} octahedra. In contrast to the network substructure of 4.7H2O, which contains binuclear and trinuclear vanadium clusters, the layers of 5.3.5 H2O are constructed from chains of corner-sharing {VO4F2} octahedra. Thermal studies of the open framework materials 4 and 5 reveal that incorporation of fluoride into the inorganic substructures provides robust scaffoldings that retain their crystallinity to 450 degrees C and above. In the case of 4, dehydration does not change the powder X-ray diffraction pattern of the material, which remains substantially unchanged to 450 degrees C. In the case of 5, there are two dehydration steps, that is, the higher temperature process associated with loss of coordinated water. This second dehydration results in structural changes as monitored by powder X-ray diffraction, but this new phase is retained to ca. 450 degrees C. The materials of this study exhibit a range of reduced oxidation states: 1 is mixed valence V(IV)/V(III) while 2 and 4.7H(2)O are exclusively V(IV) and 3 and 5.3.5H2O are exclusively V(III). These oxidation states are reflected in the magnetic properties of the materials. The paramagnetism of 1 arises from the presence of V(III) and V(IV) sites and conforms to the Curie-Weiss law with C = 2.38 em K/(Oe mol) and = -66 K with mu(eff) (300 K) = 4.33 mu(B). Compounds 3-5 exhibit Curie-Weiss law dependence of magnetism on temperature with mu(eff) (300 K) = 5.45 mu(B) for 3 (six V(III) sites), mu(eff) = 4.60 mu(B) for 4 (seven V(IV) sites) and mu(eff) = 4.13 mu(B) for 5 (two V(III) sites). Compound 2 exhibits antiferromagnetic interactions, and the magnetism may be described in terms of the Heisenberg linear antiferromagnetic chain model for V(IV). The effective magnetic moment at 300 K is 2.77 mu(B) (two V(IV) sites).     

Vapochromic behavior of {Ag2(Et2O)2[Au(C6F5)2]2}n with volatile organic compounds

The vapochromic behaviors of {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1), Me2CO (2), THF (3), CH3CN (4)) were studied. {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1)) was synthesized by the reaction of [Bu4N][Au(C6F5)2] with AgOClO3 in 1:1 molar ratio in CH2Cl2/Et2O (1:2). 1 was used as starting material with THF to form {Ag2L2[Au(C6F5)2]2}n (L = THF (3)). 3 crystallizes in the monoclinic space group C2/c and consists of tetranuclear units linked together via aurophilic contacts resulting in the formation of a 1D polymer that runs parallel to the crystallographic z axis. The gold(I) atoms are linearly coordinated to two pentafluorophenyl groups and display additional Au...Ag close contacts within the tetranuclear units with distances of 2.7582(3) and 2.7709(3) A. Each silver(I) center is bonded to the two oxygen atoms of the THF molecules with a Ag-O bond distance of 2.307(3) A. TGA analysis showed that 1 loses two molecules of the coordinated solvent per molecular unit (1st one: 75-100 degrees, second one: 150-175 degrees C), whereas 2, 3, and 4 lose both volatile organic compounds (VOCs) and fluorinated ligands in a less well defined manner. Each complex loses both the fluorinated ligands and the VOCs by a temperature of about 325 degrees C to give a 1:1 gold/silver product. X-ray powder diffraction studies confirm that the reaction of vapors of VOCs with 1 in the solid state produce complete substitution of the ether molecules by the new VOC. The VOCs are replaced in the order CH3CN > Me2CO > THF > Et2O, with the ether being the easiest to replace. {Ag2(Et2O)2[Au(C6F5)2]2}n and {Ag2(THF)2[Au(C6F5)2]2} n both luminesce at room temperature and at 77 K in the solid state. Emission maxima are independent of the excitation wavelength used below about 500 nm. Emission maxima are obtained at 585 nm (ether) and 544 nm (THF) at room temperature and at 605 nm (ether) and 567 nm (THF) at 77 K.     

Synthesis and Structural Characterization of a New Polyoxovanadium Borate: (H_3NCH_2CH_2NH_3)_4[(VO)_6(B_(10)O_(22))_2]·(H_3O)_7

1 INTRODUCTION Transition metal oxide clusters and their deriva- tives offer an unmatched variety of structural motifs and wide ranging applications in several areas, such as analytical chemistry, materials science and cataly- sis, nanotechnology, chemical sensing, environmental decontamination, biochemical and geochemical pro- cesses, and medicine[1～3]. Polyoxovanadates or vana- dium oxide clusters constitute an important subclass of polyoxometalates and have been studied exten- sively.…     

M(bipyridine)V(4)O(10) (M = Cu, Ag): hybrid analogues of low-dimensional reduced vanadates

New hybrid layered vanadates, M(bpy)V4O10 (I, M = Cu+; II, M = Ag+; bpy = 4,4'-bipyridine), were prepared from hydrothermal reactions at 220-230 degrees C, and their structures were characterized by single-crystal X-ray diffraction [I, P21/c (No. 14), Z = 4, a = 3.6154(3) A, b = 21.217(1) A, c = 20.267(1) A, and beta = 90.028(3) degrees ; II, P (No. 2), Z = 2, a = 3.5731(4) A, b = 10.429(1) A, c = 21.196(2) A, alpha = 89.031(5) degrees , beta = 89.322(5) degrees , and gamma = 85.546(5) degrees ]. The structures of I and II are closely related, though not isostructurally, with both containing partially reduced V4O10- layers that are constructed from zigzag chains of edge-sharing VO5 tetragonal pyramids. Neighboring zigzag chains within a layer condense via shared vertices and alternate between versions containing V4.5+ and V5+ ions, such that two out of four symmetry-unique V atoms are reduced by a half-electron on average. The interlayer spaces contain unusual M(bpy)+ chains formed from the coordination of two bridging bpy ligands to Ag+/Cu+ in a nearly linear fashion and each with a third bond to a single apical O atom of the reduced (V4.5+) VO5 tetragonal pyramids. Both I and II are stable until approximately 350-400 degrees C in O2, at which point the ligands are liberated to yield the purely inorganic MxV4O10 (M = Ag, Cu) solids. The electrical conductivities of both compounds show a temperature dependence that is consistent with Mott's variable-range-hopping model for randomly localized electrons. Magnetic susceptibilities of both I and II can be fitted to a Curie-Weiss expression (theta = -25 and -31 K, respectively; C approximately 0.40 emu.mol-1.K for both) at higher temperatures and one unpaired spin per formula. However, at below approximately 12-18 K, both show evidence for an antiferromagnetic transition that can be fitted well to the Heisenberg linear antiferromagnetic chain model. These results are analyzed with respect to related reduced vanadates and help to provide new structure-property insights for strongly correlated electron systems.     

Synthesis and Structural Characterization of a New Polyoxovanadium Borate: (H3NCH2CH2NH3)4[(VO)6(B10O22)2]·(H3O)7

The title compound (H3NCH2CH2NH3)4[(VO)6(B10O22)2](H3O)7 1 has been synthe- sized by the hydrothermal method and determined by X-ray crystallography.Crystallographic data: monoclinic, space group C2/c, a = 20.250(4), b = 13.448(3), c = 21.655(4) (A), β = 97.05(3)°, Mr = 851.74 (C4H30.5B10N4O28.5V3), V = 5852(2) (A)3, Z = 8, Dc = 1.933 g/cm3, μ = 1.057 mm-1, F(000) = 3436, R = 0.0500 and wR = 0.1442 for 4511 observed reflections with I > 2δ(I).The structure con- sists of [(VO)6(B10O22)2]15- cluster anions that have a central band of six trans-edge-sharing VO5 square pyramids capped by two [B10O22]14- polyborate ligands.Other characterizations are also describ- ed by elemental analysis, IR spectrum and thermal analysis.     

New vanadium selenites: centrosymmetric Ca2(VO2)2(SeO3)3(H2O)2, Sr2(VO2)2(SeO3)3, and Ba(V2O5)(SeO3), and noncentrosymmetric and polar A4(VO2)2(SeO3)4(Se2O5) (A = Sr2+ or Pb2+)

Five new vanadium selenites, Ca(2)(VO(2))(2)(SeO(3))(3)(H(2)O)(2), Sr(2)(VO(2))(2)(SeO(3))(3), Ba(V(2)O(5))(SeO(3)), Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), have been synthesized and characterized. Their crystal structures were determined by single crystal X-ray diffraction. The compounds exhibit one- or two-dimensional structures consisting of corner- and edge-shared VO(4), VO(5), VO(6), and SeO(3) polyhedra. Of the reported materials, A(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) (A = Sr(2+) or Pb(2+)) are noncentrosymmetric (NCS) and polar. Powder second-harmonic generation (SHG) measurements revealed SHG efficiencies of approximately 130 and 150 × α-SiO(2) for Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), respectively. Piezoelectric charge constants of 43 and 53 pm/V, and pyroelectric coefficients of -27 and -42 μC/m(2)·K at 70 °C were obtained for Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), respectively. Frequency dependent polarization measurements confirmed that the materials are not ferroelectric, that is, the observed polarization cannot be reversed. In addition, the lone-pair on the Se(4+) cation may be considered as stereo-active consistent with calculations. For all of the reported materials, infrared, UV-vis, thermogravimetric, and differential thermal analysis measurements were performed. Crystal data: Ca(2)(VO(2))(2)(SeO(3))(3)(H(2)O)(2), orthorhombic, space group Pnma (No. 62), a = 7.827(4) ?, b = 16.764(5) ?, c = 9.679(5) ?, V = 1270.1(9) ?(3), and Z = 4; Sr(2)(VO(2))(2)(SeO(3))(3), monoclinic, space group P2(1)/c (No. 12), a = 14.739(13) ?, b = 9.788(8) ?, c = 8.440(7) ?, β = 96.881(11)°, V = 1208.8(18) ?(3), and Z = 4; Ba(V(2)O(5))(SeO(3)), orthorhombic, space group Pnma (No. 62), a = 13.9287(7) ?, b = 5.3787(3) ?, c = 8.9853(5) ?, V = 673.16(6) ?(3), and Z = 4; Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), orthorhombic, space group Fdd2 (No. 43), a = 25.161(3) ?, b = 12.1579(15) ?, c = 12.8592(16) ?, V = 3933.7(8) ?(3), and Z = 8; Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), orthorhombic, space group Fdd2 (No. 43), a = 25.029(2) ?, b = 12.2147(10) ?, c = 13.0154(10) ?, V = 3979.1(6) ?(3), and Z = 8.     

Synthesis and Crystal Structure of a 3-D Hydrogen-bonded Supramolecular Decavanadate Compound [Habo]_6[V_(10)O_(28)]·2C_3H_7OH·2H_2O

1 INTRODUCTION The chemistry of polyoxometalates has been at- tracting much attention due to the richness in their structures, electron and proton storage abilities, ther- mal stability and applications in catalysis, medicine and surface sciences[1～3]. In recent years, the mixed- valence as well as full oxidized vanadium polyoxo- anions have been crystallized with a variety of orga- nic molecules as counteranions[4～8]. However, the guiding principles of the crystal structures of poly- o…     

Ag(I)/V(V) Heterobimetallic Frameworks Generated from Novel-Type {Ag(2)(VO(2)F(2))(2)(triazole)(4)} Secondary Building Blocks: A New Aspect in the Design of SVOF Hybrids

A series of new silver(I)-containing MOFs [Ag(2)(tr(2)ad)(2)](ClO(4))(2) (1), [Ag(2)(VO(2)F(2))(2)(tr(2)ad)(2)]·H(2)O (2), [Ag(2)(VO(2)F(2))(2)(tr(2)eth)(2)(H(2)O)(2)] (3), and [Ag(2)(VO(2)F(2))(2)(tr(2)cy)(2)]·4H(2)O (4) supported by 4-substituted bifunctional 1,2,4-triazole ligands (tr(2)ad = 1,3-bis(1,2,4-triazol-4-yl)adamantane, tr(2)eth = 1,2-bis(1,2,4-triazol-4-yl)ethane, tr(2)cy = trans-1,4-bis(1,2,4-triazol-4-yl)cyclohexane) were hydrothermally synthesized and structurally characterized. In these complexes, the triazole heterocycle as an N(1),N(2)-bridge links either two adjacent Ag-Ag or Ag-V centers at short distances forming polynuclear clusters. The crystal structure of compound 1 is based on cationic {Ag(2)(tr)(4)}(2+) fragments connected in a 2D rhombohedral grid network with (4,4) topology. The neighboring layers are tightly packed into a 3D array by means of argentophilic interactions (Ag···Ag 3.28 ?). Bridging between different metal atoms through the triazole groups assists formation of heterobimetallic Ag(I)/V(V) secondary building blocks in a linear V-Ag-Ag-V sequence that is observed in complexes 2-4. These unprecedented tetranuclear {Ag(2)(VO(2)F(2))(2)(tr)(4)} units (the intermetal Ag-Ag and Ag-V distances are 4.24-4.36 and 3.74-3.81 ?, respectively), in which vanadium(V) oxofluoride units possess distorted trigonal bipyramidal environment {VO(2)F(2)N}ˉ, are incorporated into 1D ribbon (2) or 2D square nets (3, 4) using bitopic μ(4)-triazole ligands. The valence bond calculation for vanadium atoms shows +V oxidation state in the corresponding compounds. Thermal stability and photoluminescence properties were studied for all reported coordination polymers.     

Single-crystal growth and characterization of disilver(I) monofluorophosphate(V), Ag2PO3F: crystal structure, thermal behavior, vibrational spectroscopy, and solid-state 19F, 31P, and 109Ag MAS NMR spectroscopy

Single crystals of disilver(I) monofluorophosphate(V), Ag2PO3F (1), were obtained by slow evaporation of a diluted aqueous Ag2PO3F solution. Compound 1 adopts a new structure type and crystallizes in the monoclinic space group C2/c with eight formula units and lattice parameters of a = 9.2456(8) A, b = 5.5854(5) A, c = 14.7840(13) A, and beta = 90.178(2) degrees. The crystal structure of 1 [R(F2 > 2sigma(F2) = 0.0268, wR(F2 all) = 0.0665] is composed of three crystallographically independent Ag+ cations and PO3F2- anions as single building units. The oxygen environment around each of the Ag+ cations is different, with one Ag+ in distorted octahedral (d(Ag-O) = 2.553 A), one in nearly rectangular (d(Ag-O) = 2.445 A), and one in distorted tetrahedral (d(Ag-O) = 2.399 A) coordination. Additional Ag-F contacts to more remote F atoms located at distances >2.80 A augment the coordination polyhedra for the two latter Ag+ cations. The monofluorophosphate anion deviates slightly from C3v symmetry and exhibits the characteristic differences in bond lengths, with a mean of 1.510 A for the P-O bonds and one considerably longer P-F bond of 1.575(2) A. Compound 1 was further characterized by vibrational spectroscopy (Raman and IR) and solid-state 19F, 31P, and 109Ag MAS NMR spectroscopy. The value for the isotropic one-bond P-F coupling constant in 1 is 1JPF = -1045 Hz. Thermal analysis (TG, DSC) revealed a reversible phase transition at 308 degrees C, which is very close to the decomposition range of 1. Under release of POF3, Ag4P2O7 and Ag3PO4 are the thermal decomposition products at temperatures above 450 degrees C.     

Ag4V2O6F2: an electrochemically active and high silver density phase

Low-temperature hydrothermal techniques were used to synthesize single crystals of Ag(4)V(2)O(6)F(2). This previously unreported oxide fluoride phase was characterized by single-crystal X-ray diffraction and IR spectroscopy and was also evaluated as a primary lithium battery cathode. Crystal data: monoclinic, space group P2(1)/n (No. 14), with a = 8.4034(4) A, b = 10.548(1) A, c = 12.459(1) A, beta = 90.314(2) degrees , and Z = 4. Ag(4)V(2)O(6)F(2) (SVOF) exhibits two characteristic regions within the discharge curve, an upper plateau at 3.5 V, and a lower sloped region around 2.3 V from reduction of the vanadium oxide fluoride framework. The material has a nominal capacity of 251 mAh/g, with 148 mAh/g above 3 V. The upper discharge plateau at 3.5 V is nearly 300 mV over the silver reduction potential of the commercial primary battery material, Ag(2)V(4)O(11) (SVO).     

New d0 transition metal iodates: synthesis, structure, and characterization of BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4.(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4.H2O

Five new d0 transition metal iodates, BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4.(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4.H2O, have been synthesized by hydrothermal methods using Ba(OH)2.8H2O, La2O3, K2CO3, TiO2, V2O5, MoO3, and HIO3 as reagents. The structures of these compounds were determined by single-crystal X-ray diffraction. All of the reported materials have zero-dimensional or pseudo-one-dimensional crystal structures composed of MO6 (M = Ti4+, V5+, or Mo6+) octahedra connected to IO3 polyhedra. Infrared and Raman spectroscopy, thermogravimetric analysis, and UV-vis diffuse reflectance spectroscopy are also presented. Crystal data: BaTi(IO3)6, trigonal, space group R-3 (No. 148), with a = b = 11.4711(10) A, c = 11.1465(17) A, V = 1270.2(2) A3, and Z = 3; LaTiO(IO3)5, monoclinic, space group P2(1)/n (No. 14), with a = 7.4798(10) A, b = 18.065(2) A, c = 10.4843(14) A, beta = 91.742(2) degrees , V = 1416.0(3) A3, and Z = 4; Ba2VO2(IO3)4.(IO3), monoclinic, space group P2(1)/c (No. 14), with a = 7.5012(9) A, b = 33.032(4) A, c = 7.2150(9) A, beta = 116.612(2) degrees , V = 1598.3(3) A3, and Z = 4; K2MoO2(IO3)4, monoclinic, space group C2/c (No. 15), with a = 12.959(2) A, b = 6.0793(9) A, c = 17.748(3) A, beta = 102.410(4) degrees , V = 1365.5(4) A3, and Z = 4; BaMoO2(IO3)4.H(2)O, monoclinic, space group P2(1)/n (No. 14), with a = 13.3368(17) A, b = 5.6846(7) A, c = 18.405(2) A, beta = 103.636(2) degrees , V = 1356.0(3) A3, and Z = 4.     

Experimental and theoretical study of the reactions between neutral vanadium oxide clusters and ethane, ethylene, and acetylene

Reactions of neutral vanadium oxide clusters with small hydrocarbons, namely C2H6, C2H4, and C2H2, are investigated by experiment and density functional theory (DFT) calculations. Single photon ionization through extreme ultraviolet (EUV, 46.9 nm, 26.5 eV) and vacuum ultraviolet (VUV, 118 nm, 10.5 eV) lasers is used to detect neutral cluster distributions and reaction products. The most stable vanadium oxide clusters VO2, V2O5, V3O7, V4O10, etc. tend to associate with C2H4 generating products V(m)O(n)C2H4. Oxygen-rich clusters VO3(V2O5)(n=0,1,2...), (e.g., VO3, V3O8, and V5O13) react with C2H4 molecules to cause a cleavage of the C=C bond of C2H4 to produce (V2O5)(n)VO2CH2 clusters. For the reactions of vanadium oxide clusters (V(m)O(n)) with C2H2 molecules, V(m)O(n)C2H2 are assigned as the major products of the association reactions. Additionally, a dehydration reaction for VO3 + C2H2 to produce VO2C2 is also identified. C2H6 molecules are quite stable toward reaction with neutral vanadium oxide clusters. Density functional theory calculations are employed to investigate association reactions for V2O5 + C2H(x). The observed relative reactivity of C2 hydrocarbons toward neutral vanadium oxide clusters is well interpreted by using the DFT calculated binding energies. DFT calculations of the pathways for VO3+C2H4 and VO3+C2H2 reaction systems indicate that the reactions VO3+C2H4 --> VO2CH2 + H2CO and VO3+C2H2 --> VO2C2 + H2O are thermodynamically favorable and overall barrierless at room temperature, in good agreement with the experimental observations.     

Structural Variability of the Vanadium-Organodiphosphonate System: Hydrothermal Syntheses and Structural Characterizations of One-Dimensional, Two-Dimensional, and Three-Dimensional Phases

The hydrothermal chemistry of the CsVO(3)/methylenediphosphonate system was investigated. Variations in reaction temperatures, heating times, and stoichiometries of reactants resulted in the isolation of mononuclear, one-, two-, and three-dimensional species: Cs[VO(HO(3)PCH(2)PO(3)H)(2)(H(2)O)] (1), Cs[VO(HO(3)PCH(2)PO(3))] (2), Cs[(VO)(2)V (O(3)PCH(2)PO(3))(2)(H(2)O)(2)] (3), and [V(HO(3)PCH(2)PO(3))(H(2)O)] (4), respectively. The structure of the anion of 1 consists of isolated V(IV) octahedra. Phase 2 adopts a chain structure constructed from corner-sharing V(IV) octahedra, forming infinite {-V=OV=O-} linkages. The layer structure of 3 contains trinuclear units of corner-sharing {VO(6)} octahedra with the central V site in the III oxidation state and V(IV) centers at the extremities of the cluster. The diphosphonate ligands serve to link neighboring trinuclear motifs into a layer structure three octahedra in depth. The Cs(+) cations occupy cavities within the layers, rather than the more common interlamellar positions. The structure of 4 consists of isolated {V(III)O(6)} octahedra linked by diphosphonate groups into a three-dimensional framework. Crystal data: for 1, CH(6)O(7)P(2)V(0.5)Cs, monoclinic C2, a = 10.991(2) ?, b = 10.161(2) ?, c = 7.445(1) ?, beta = 92.97(3) degrees, Z = 4; for 2, CH(3)O(7)P(2)VCs, monoclinic C2, a = 10.212(2) ?, b = 10.556(2) ?, c = 14.699(3) ?, beta = 94.57(2) degrees, Z = 8; for 3, C(2)H(8)O(16)P(4)V(3)Cs, monoclinic C2/m, a = 9.724(2) ?, b = 8.136(2) ?, c = 10.268(2) ?, beta = 103.75(3) degrees, Z = 2; for 4, CH(5)O(7)P(2)V, monoclinic P2(1)()/n, a = 5.341(1) ?, b = 11.516(2) ?, c = 10.558(2) ?, beta = 99.89(1) degrees, Z = 4.     

Site-specific vanadates Co4Fe3.33(VO4)6 and Mn3Fe4(VO4)6

Single crystals of Co4Fe3.33(VO4)6 and Mn3Fe4(VO4)6 were grown from equivalent CoO/Fe2O3/V2O5 and MnO/Fe2O3/V2O5 melts, respectively. The former crystallizes in the orthorhombic space group Pnma with parameters a = 4.965(1) A, b = 10.211(1) A, c = 17.188(3) A, and Z = 2 and is a homeotype of such catalysts as Mg2.5VMoO8. The latter crystallizes in the triclinic space group P1 with parameters a = 6.703(2) A, b = 8.137(1) A, c = 9.801(2) A, alpha = 105.56(1) degrees, beta = 105.58(2) degrees, gamma = 102.35(1) degrees, and Z = 1 and is a homeotype of beta-Cu3Fe4(VO4)6, the low-pressure form of alpha-Cu3Fe4(VO4)6. The cobalt analogue deviates in stoichiometry from the reactant melt to form the more dense alpha-Cu3Fe4(VO4)6 structure type comprised of partially occupied face-sharing octahedral and trigonal prismatic coordination sites.     

A covalent vanadium(III) 2-dimensional network and vanadyl chains linked by aryldioxides

Thermolysis of (iPrO)4V and 2,6-dihydroxynaphthalene in 4-(3-phenylpropyl)pyridine afforded [mer-V(mu 2,6-OC10H6O)1.5(4-(3-phenylpropyl)py)3]n (1; C57H54N3O3V, triclinic, P1, a = 10.450(2) A, b = 14.098(3) A, c = 16.765(3) A, alpha = 100.09(3) degrees, beta = 103.85(3) degrees, gamma = 103.08(3) degrees, Z = 2) and oxidation product bis-2,6-dinaphthol. Paramagnetic (S = 1) 1 adopts a bricklike motif of aryldioxide-connected V(III) centers whose channels are filled with the bound 4-(3-phenylpropyl)py. A similar procedure involving (iPrO)3VO provided the linear chain [(mu 2,6-OC10H6O)(4-(3-phenylpropyl)py)2VO]n (2; C38H36N2O3V, monoclinic, P2(1)/c, a = 10.6172(2) A, b = 9.4477(3) A, c = 31.8129(8) A, beta = 95.20(3) degrees, Z = 4). Interchain pyridine ring-edge to phenyl-face interactions generate a sheet of like-oriented oxos, but adjacent sheets are oriented in opposition so that no net dipole exists. Another 1-dimensional chain, [(mu 1,4-OC6H4O)(py)2VO]n (3; C16H14N2O3V, monoclinic, P2(1)/c, a = 8.377(2) A, b = 16.675(3) A, c = 11.061(2) A, beta = 103.91(3) degrees, Z = 4), was prepared by heating (iPrO)4V and hydroquinone in pyridine. Pyridines of adjacent chains interpenetrate to form a sheet, but oxos in adjacent chains are now in opposition.     

Gold(I) and silver(I) metallocryptates based on 2,9-bis(diphenylphosphino)-1,8-naphthyridine

In acetonitrile the rigid diphosphine ligand 2,9-bis(diphenylphosphino)-1,8-naphthyridine (dppn) reacts with (SMe2)AuCl in the presence of NaPF6 to produce a pale-yellow material identified as [Au2Na(mu-dppn)3](PF6)3 (1). In acetonitrile dppn reacts with 2 equiv of (SMe2)AuCl to form the simple Au-Cl adduct of the ligand, Au2Cl2dppn (2). In a fashion analogous to that of the synthesis of 1, the reaction of equimolar AgNO3 with dppn produces the trimetallic species [Ag2(mu-dppn)3Ag](PF6)3 (3) as a bright-yellow material. 1, 2, and 3 were characterized by 31P(1H) NMR spectroscopy, electronic absorption spectroscopy, X-ray crystallography, emission spectroscopy, and elemental analysis. Additionally 1 was further characterized by cyclic voltammetry and mass spectrometry. 1.4.5CH3CN.0.5(C2H5)2O (C107H72Au2F18N10.5NaO) crystallizes in the triclinic space group P1 with a = 15.408(3) A, b = 17.295(3) A, c = 22.425(5) A, alpha = 73.68(1) degrees, beta = 77.32(1) degrees, gamma = 74.18(1) degrees, V = 5451.4(19) A3, and Z = 2. C32H24Au2Cl2N2P2 (2) crystallizes in the monoclinic space group Cc with a = 10.936(2) A, b = 19.860(5) A, c = 20.864(2) A, beta = 118.182(1) degrees, V = 3127.3(8) A3, and Z = 4. Compound 3 crystallizes as the bis-DMSO adduct (C101H84Cl2F18N6O2P9S2) in the monoclinic space group C2/c with a = 28.825(7) A, b = 17.013(3) A, c = 23.916(7) A, beta = 115.23(1) degrees, V = 10609.6(44) A3, and Z = 4. The structures of 1 and 3 contain a three-coordinate metal capping the metallocryptate with an encapsulated ion. The central Ag(I) ion in 3 is positioned off-center to form a short Ag...Ag interaction of 3.145(2) A, while the central Na+ ion of 1 is centrally positioned with long Au...Na interactions of approximately 3.5 A. The solution-state properties of 1 were probed. 1 is emissive, as are the Li, K, and Cs analogues.