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An examination of manganese silicates and germanates revealed unusual structural motifs and extremely different chemistries, with identical hydrothermal reactions forming K2Mn2Si3O9 versus K11Mn21Ge32O86(OH)9(H2O). The germanate is exceptional in both its c-axis length (exceeding 76 A) and unit cell volume (nearly 18000 A3), the largest known polygermanate structure to our knowledge.

A new member of the descloizite family, a cobalt vanadate, SrCo(VO4)(OH), has been synthesized as large single crystals using high-temperature and high-pressure hydrothermal methods. SrCo(VO4)(OH) crystallizes in the orthorhombic crystal system in space group P212121 with the following unit cell parameters: a = 6.0157(2) A, b = 7.645(2) A, c = 9.291(3) A, V = 427.29(2) A3, and Z = 4. It contains one-dimensional Co-O-Co chains of edge-sharing CoO6 octahedra along the a-axis connected to each other via VO4 tetrahedra along the b-axis forming a three-dimensional structure. The magnetic susceptibility of SrCo(VO4)(OH) indicates an antiferromagnetic transition at 10 K as well as unusually large spin orbit coupling. Single-crystal magnetic measurements in all three main crystallographic directions displayed a significant anisotropy in both temperature- and field-dependent data. Single-crystal neutron diffraction at 4 K was used to characterize the magnetically ordered state. The Co2+ magnetic spins are arranged in a staggered configuration along the chain direction, with a canting angle that follows the tipping of the CoO6 octahedra. The net magnetization along the chain direction, resulting in ferromagnetic coupling of the a-axis spin components in each chain, is compensated by an antiferromagnetic interaction between nearest neighbor chains. A metamagnetic transition appears in the isothermal magnetization data at 2 K along the chain direction, which seems to correspond to a co-alignment of the spin directions of the nearest neighbor chain. We propose a phenomenological spin Hamiltonian that describes the canted spin configuration of the ground state and the metamagnetic transition in SrCo(VO4)(OH).

An examination of manganese silicates and germanates revealed unusual structural motifs and extremely different chemistries, with identical hydrothermal reactions forming K

The magnetic properties are reported for three members of the glaserite series of compounds, Na2BaM(VO4)2, M = Mn, Mn0.6Co0.4, and Co. Large single crystals are grown using a high-temperature hydrothermal synthesis method. This structure type exhibits a triangular magnetic lattice in which M2+O6 octahedra are interconnected with nonmagnetic (VO4)3- groups. All the structures crystallize at room temperature with rigid trigonal symmetry (space group P3 m1); however, at lower temperatures both Na2BaMn(VO4)2 and Na2BaMn0.6Co0.4(VO4)2 undergo a structural transition to lower symmetry (monoclinic, C2/ c). The bulk magnetic measurements indicate that Mn- and Co-structures are antiferromagnetic and ferromagnetic, respectively. Na2BaMn0.6Co0.4(VO4)2 does not show any long-range ordering down to 0.5 K, although a broad heat capacity anomaly near 1.2 K suggests short-range magnetic order or freezing into a spin-glass-like state related to the chemical disorder and resulting competing magnetic interactions. The magnetic structures of Na2BaMn(VO4)2 and Na2BaCo(VO4)2 were determined using neutron powder diffraction. At zero magnetic field, Na2BaMn(VO4)2 possesses an antiferromagnetic structure with the moments ordered in a Neel-type arrangement and aligned along the C4 axis of the octahedra. Under applied magnetic field at 0.3 K, the evolution of the magnetic structure toward a fully polarized state is observed. Na2BaCo(VO4)2 represents a ferromagnetic (FM) magnetic structure with Co moments aligned parallel to the c-axis direction. The relationships between these structures and magnetic properties are discussed.

Large single crystals of Yb2Ge2O7 in the cubic Fd3m space group, are synthesized and characterized from a high-temperature hydrothermal method (650°C/200 MPa in 1 M KF). The cubic phase displays spin frustration and possibly nonclassical quantum-spin behavior at low temperature. This is the first report of single crystals of this important phase of size and quality suitable for single-crystal neutron diffraction.

The structural and magnetic properties of a glaserite-type Na2BaFe(VO4)2 compound, featuring a triangular magnetic lattice of Fe2+ (S = 2), are reported. Temperature dependent X-ray single crystal studies indicate that at room temperature the system adopts a trigonal P3m1 structure and undergoes a structural phase transition to a C2/c monoclinic phase slightly below room temperature (Ts = 288 K). This structural transition involves a tilting of Fe-O-V bond angles and strongly influences the magnetic correlation within the Fe triangular lattice. The magnetic susceptibility measurements reveal a ferromagnetic transition near 7 K. Single crystal neutron diffraction confirms the structural distortion and the ferromagnetic spin ordering in Na2BaFe(VO4)2. The magnetic structure of the ordered state is modeled in the magnetic space group C2'/c' that implies a ferromagnetic order of the a and c moment components and antiferromagnetic arrangement for the b components. Overall, the Fe magnetic moments form ferromagnetic layers that are stacked along the c-axis, where the spins point along one of the (111) facets of the FeO6 octahedron.

Two terbium germanates have been synthesized via high-temperature and high-pressure hydrothermal synthesis with 20 M KOH as a mineralizer using Tb4O7 as a starting material. Tb13(GeO4)6O7(OH) crystallizes in trigonal space group R3, is built up of isolated GeO4 units, and contains a complex arrangement of terbium oxide polyhedra. K2TbGe2O7 is a terbium(4+) pyrogermanate that is isostructural with K2ZrGe2O7 and displays a rare stable Tb4+ oxidation state in the solid state.

A new member of the descloizite family, a cobalt vanadate, SrCo(VO

Manganese vanadate fluorides were synthesized using high-temperature hydrothermal techniques with BaF2 as a mineralizer. Ba3Mn2(V2O7)2F2 crystallizes in space group C2/c and consists of dimers built from edge-sharing MnO4F2 trigonal prisms with linking V2O7 groups. Ba7Mn8O2(VO4)2F23 crystallizes in space group Cmmm, with a manganese oxyfluoride network built from edge- and corner-sharing Mn2+/3+(O,F)6 octahedra. These octahedra form alternating Mn2+ and Mn2+/3+ layers separated by VO4 tetrahedra. This latter compound exhibits a canted antiferromagnetic order below TN = 25 K.

New complex manganese vanadate materials were synthesized as high-quality single crystals in multi-millimeter lengths using a high-temperature, high-pressure hydrothermal method. One compound, Mn5(VO4)2(OH)4, was grown from Mn2O3 and V2O5 in 3 M CsOH at 580 °C and 1.5 kbar. Changing the mineralizer to 1 M CsOH/3MCsCl leads to the formation of another product, Mn6O(VO4)2(OH). Both compounds were structurally characterized by single-crystal X-ray diffraction (Mn5(VO4)2(OH)4: C2/m, Z = 2, a = 9.6568(9) Å, b = 9.5627(9) Å, c = 5.4139(6) Å, β = 98.529(8)°; Mn6O(VO4)2(OH): P21/m, Z = 2, a = 8.9363(12) Å, b = 6.4678(8) Å, c = 10.4478(13) Å, β = 99.798(3)°), revealing interesting low-dimensional transition-metal features. Mn5(VO4)2(OH)4 possesses complex honeycomb-type Mn-O layers, built from edge-sharing [MnO6] octahedra in the bc plane, with bridging vanadate groups connecting these layers along the a-axis. Mn6O(VO4)2(OH) presents a more complicated structure with both octahedral [MnO6] and trigonal bipyramidal [MnO5] units. A different pattern of planar honeycomb sheets are formed by edge-shared [MnO6] octahedra, and these sublattices are connected through edge-shared dimers of [MnO5] trigonal bipyramids to form corrugated sheets. Vanadate groups again condense the sheets into a three-dimensional framework. Infrared and Raman spectroscopies indicated the presence of OH groups and displayed characteristic Raman scattering due to vanadate groups. Temperature-dependent magnetic studies indicated Curie-Weiss behavior above 100 K with significant anti-ferromagnetic coupling for both compounds, with further complex magnetic behavior at lower temperatures. The data indicate canted anti-ferromagnetic order below 57 K in Mn5(VO4)2(OH)4 and below 45 K in Mn6O(VO4)2(OH). Members of another class of compounds, K2M3(VO4)2(OH)2 (M = Mn, Co), also containing a honeycomb-type sublattice, were also synthesized to allow a comparison of the structural features across all three structure types and to demonstrate extension to other transition metals.

Large single crystals of Yb

A new series of transition metal vanadates, namely, Ba2M(VO4)2(OH) (M = V(3+), Mn(3+), and Fe(3+)), was synthesized as large single crystals hydrothermally in 5 M NaOH solution at 580 °C and 1 kbar. This new series of compounds is structurally reminiscent of the brackebuschite mineral type. The structure of Ba2V(VO4)2(OH) is monoclinic in space group P21/m, a = 7.8783(2) Å, b = 6.1369(1) Å, c = 9.1836(2) Å, β = 113.07(3)°, V = 408.51(2) Å(3). The other structures are similar and consist of one-dimensional trans edge-shared distorted octahedral chains running along the b-axis. The vanadate groups bridge across edges of their tetrahedra. Structural analysis of the Ba2Mn(VO4)2(OH) analogue yielded a new understanding of the Jahn-Teller effect in this structure type. Raman and infrared spectra were investigated to observe the fundamental vanadate and hydroxide vibrational modes. Single-crystal temperature-dependent magnetic studies on Ba2V(VO4)2(OH) reveal a broad feature over a wide temperature range with maximum at ∼100 K indicating that an energy gap could exist between the antiferromagnetic singlet ground state and excited triplet states, making it potentially of interest for quantum magnetism studies.

The structural and magnetic properties of a glaserite-type Na

Two terbium germanates have been synthesized via high-temperature and high-pressure hydrothermal synthesis with 20 M KOH as a mineralizer using Tb

Three new barium manganese vanadates, all containing hexagonal barium chloride layers interpenetrated by [V2O7]4– groups, were synthesized using a high-temperature (580 °C) hydrothermal method. Two of the compounds were prepared from a mixed BaCl2/Ba(OH)2 mineralizer, and the third compound was prepared from BaCl2 mineralizer. An interesting structural similarity exists between two of the compounds, Ba2Mn(V2O7)(OH)Cl and Ba4Mn2(V2O7)(VO4)2O(OH)Cl. These two compounds crystallize in the orthorhombic space group Pnma, Z = 4, and are structurally related by a nearly doubled a axis. The first structure, Ba2Mn(V2O7)(OH)Cl (I) (a = 15.097(3) A, b = 6.1087(12) A, c = 9.5599(19) A), consists of octahedral manganese(II) edge-sharing chains linked by pyrovanadate [V2O7] groups, generating a three-dimensional structure. Compound II, Ba4Mn2(V2O7)(VO4)2O(OH)Cl (a = 29.0814(11) A, b = 6.2089(2) A, c = 9.5219(4) A), is composed of manganese(III) edge-sharing chains that are coordinated to one another through pyrovanadat...

Manganese vanadate fluorides were synthesized using high-temperature hydrothermal techniques with BaF

This paper describes the hydrothermal chemistry of alkali hafnium fluorides, including the synthesis and structural characterization of five new alkali hafnium fluorides. Two ternary alkali hafnium fluorides are described: Li(2)HfF(6) in space group P31m with a = 4.9748(7) Å and c = 4.6449(9) Å and Na(5)Hf(2)F(13) in space group C2/m with a = 11.627(2) Å, b = 5.5159(11) Å, and c = 8.4317(17) Å. Three new alkali hafnium oxyfluorides are also described: two fluoroelpasolites, K(3)HfOF(5) and (NH(4))(3)HfOF(5), in space group Fm3m with a = 8.9766(10) and 9.4144(11) Å, respectively, and K(2)Hf(3)OF(12) in space group R3m with a = 7.6486(11) Å and c = 28.802(6) Å. Infrared (IR) spectra were obtained for the title solids to confirm the structure solutions. Comparison of these materials was made based on their structures and synthesis conditions. The formation of these species in hydrothermal fluids appears to be dependent upon both the concentration of the alkali fluoride mineralizer solution and the reaction temperature. Both X-ray and visible fluorescence studies were conducted on compounds synthesized in this study and showed that fluorescence was affected by a variety of factors, such as alkali metal size, the presence/absence of oxygen in the compound, and the coordination environment of Hf(4+).

The synthesis and structure of the isostructural acentric compounds Sr(3)Be(2)B(5)O(12)(OH) (1) and Ba(3)Be(2)B(5)O(12)(OH) (2) are reported for the first time. These compounds crystallize in the space group R3m, and the unit cell parameters are a = 10.277(15) Å and c = 8.484(17) Å for 1 and a = 10.5615(15) Å and c = 8.8574(18) Å for 2. The structures consist of a network of [Be(2)B(4)O(12)(OH)] units interwoven with a network consisting of MO(9) polyhedra (M = Sr, Ba) and BO(3) triangles and exemplify how acentric building blocks such as [BO(3)](3-), [BO(4)](5-), and [BeO(4)](6-) can be especially suitable to build noncentrosymmetric long-range structures. Both networks are centered on the 3-fold rotation axis and present themselves in alternating fashion along [001]. Acentricity is imparted by the alignment of the polarities of BO(3) and BeO(4) environments. Infrared spectroscopy has been used to confirm the local geometries of B and Be, as well as the presence of hydroxide in the crystal structure. Another interesting feature of these compounds is the presence of disorder involving Be and B at the tetrahedral Be site. The degree of the disorder has been confirmed by observing a noticeable shortening of average Be-O bond distances.

Two novel, noncentrosymmetric borate fluorides, Sr(3)B(6)O(11)F(2) and Ba(3)B(6)O(11)F(2), have been synthesized hydrothermally and their structures determined. The compounds are isostructural, crystallizing in space group P2(1), having lattice parameters of a = 6.4093 (13) Å, b = 8.2898 (17) Å, c = 9.3656 (19) Å, and β = 101.51 (3)° for Sr(3)B(6)O(11)F(2) and a = 6.5572 (13) Å, b = 8.5107 (17) Å, c = 9.6726 (19) Å, and β = 101.21 (3)° for Ba(3)B(6)O(11)F(2). The structure consists of a complex triple-ring borate framework having aligned triangular [BO(3)] groups that impart polarity. Fluorine atoms are bound only to the alkaline-earth metals and are not part of the borate framework, resulting in a vastly different structure from those of the hydrated borates Sr(3)B(6)O(11)(OH)(2) and Ba(3)B(6)O(11)(OH)(2) with similar formulas. The title compounds are transparent to nearly 200 nm, making them potentially useful for deep-ultraviolet nonlinear-optical applications.

The reaction of barium borosilicate glasses in hydrothermal fluids with NaOH mineralizer at ca. 600-650 °C in the presence of various sources of Eu(3+) ions leads to a new series of noncentrosymmetric single crystals characterized by single-crystal X-ray diffraction. Under three slightly different reaction modifications, three new Eu(3+)-containing noncentrosymmetric single crystals were isolated and characterized. Using a barium borosolicate glass with Eu(2)O(3) added to the reaction mixture led to NaBaEuSi(3)O(9) (1), which crystallizes in the noncentrosymmetric orthorhombic space group P2(1)2(1)2(1) with unit cell parameters a = 5.6373(11) Å, b = 11.483(2) Å, and c = 12.535(2) Å and consists of Eu(3+) ions linked by Si(3)O(9)(6-) rings. Using a similar glass feedstock with Eu(3+) included in the starting glass composition led to the compound NaBa(3)Eu(3)Si(6)O(20) (2), which was determined in the noncentrosymmetric polar space group Ama2 with unit cell parameters a = 14.777(3) Å, b = 23.926(5) Å, and c = 5.5533(11) Å. It is constructed of individual islands of Si(4)O(13)(10-) and lone Si(2)O(7)(6-) building fragments. Finally, use of the Eu-containing glass along with additional Eu(2)O(3) led to the compound BaEu(6)(Si(3)B(6)O(24))(OH)2 (3), which crystallizes in the polar space group P6mm with a = 10.8074(15) Å and c = 4.7296(9) Å. It is related to the rare and poorly understood mineral cappelenite Ba(Y,RE)(6)(Si(3)B(6)O(24))F(2) and contains six-membered tetrahedral borate rings linked by silicate tetrahedra. The high percentage of noncentrosymmetric crystals obtained from of a simple borosilicate glass starting material, along with various straightforward chemical additives, suggests strongly that many more noncentrosymmetric crystals can be isolated from this general system.

Two new compounds containing tellurite building blocks coordinated to copper and barium atoms have been isolated from hydrothermal solvents. A new layered compound, Ba(2)Cu(4)Te(4)O(11)Cl(4) (I), has been obtained by reacting BaCl(2).2H(2)O, CuO, and Te(OH)(6) in NH(4)Cl solution at 375 degrees C for 4 days. Green, platelike crystals of I crystallize in the centrosymmetric space group, Ponemacr;, with a = 9.275(2) Å, b = 12.135(2) Å, c = 9.263(2) Å, alpha = 98.23(3) degrees, beta = 108.35(3) degrees, gamma = 110.90(3) degrees, and Z = 2. The compound contains two types of layers, one based on copper oxides linked by Te(4)O(11) groups, and the other based on Cu(2)Cl(4) units. The tellurium atoms adopt the common TeO(3+1) units or TeO(3) pyramids, and the oxygen-coordinated copper atoms adopt a square planar CuO(4) arrangement. Dark green, prismatic crystals of BaCu(2)Te(2)O(6)Cl(2) (II) were obtained by reacting BaCl(2).2H(2)O, Cu(2)O, and Te(OH)(6) in NH(4)Cl solution at 375 degrees C for 18 h. Compound II was refined in the acentric monoclinic space group, P2(1) (a = 7.434(2) Å, b = 7.448(2) Å, c = 8.271(2) Å, beta = 97.42(3) degrees, Z = 2), and is based on Te(2)O(6) units connected by copper atoms or copper chloride groups. As in I, tellurium atoms are contained within TeO(3+1) or TeO(3) units and the connecting copper atoms are nearly square planar. The chloride-coordinated copper atoms group adopt a square pyramidal CuO(3)Cl(2) geometry with a chlorine atom occupying the apical position. The formal oxidation states of the copper atoms in compound I are distributed such that the connecting atoms in an oxide environment are 2+ and atoms within a chloride environment are 1+, whereas in compound II, all copper atoms are 2+. Bond valence sums for both compounds and magnetic susceptibility data for I support these assignments. The optical band gap for I was determined by diffuse reflectance spectroscopy and indicate that it is a wide band gap material (E(g)() = 3.00 eV).

A new pseudoternary phase, Cs(5)Sb(8)S(18)(HCO(3)), was prepared from supercritical ammonia at 160 degrees C over 4 days using stoichiometric quantities of Cs(2)CO(3), Sb(2)S(3), and S(8). Red parallelepipeds of the title phase crystallize in the centrosymmetric monoclinic space group C2/c, with a = 27.064(3) Å, b = 11.634(4) Å, c = 12.642(3) Å, beta = 97.45(2) degrees, and Z = 4. The compound has a layered structure, with the layers formed from ribbons of condensed psi-SbS(4) trigonal bipyramids linked via S(3)(2)(-) chains, and both Cs(+) and HCO(3)(-) ions between the layers, giving rise to the formula Cs(5)Sb(8)S(12)(S(3))(2)(HCO(3)). Each layer is approximately 10 Å thick, with two layers per unit cell. The condensation of the group 15/16 building blocks into ribbons is the result of a combination of edge- and vertex-shared antimony(III) sulfide pseudo trigonal bipyramids. In this phase, the S(3) chains always link adjacent ribbons via apical coordination sites on the antimony atoms. The open cavities created by the linking trisulfide dianions between neighboring ribbons accommodate the antimony lone pairs and two unique cesium cations. A third cesium cation is located between layers. Unique to this compound, the anionic antimony sulfide layers are separated not only by cesium cations but also by bicarbonate anions. Results derived from infrared spectroscopy, diffuse reflectance, bond valence sums, and magnetic susceptibility measurements support the formulation of this compound as an electron-precise, wide-bandgap material. Thermal stability studies of Cs(5)Sb(8)S(18)(HCO(3)) are also discussed.

Three new lanthanide metal polysulfides have been synthesized in supercritical ammonia: [Yb(NH3)8][Cu(S4)2]· NH3 (I), [Yb(NH3)8][Ag(S4)2]·2NH3 (II), [La(NH3)9][Cu(S4)2] (III). Compounds were prepared in sealed quartz tubes which were filled to one-third volume with liquid ammonia and heated at 170 °C for 3 days. Compounds I and II were obtained from the reaction of a premade ytterbium polysulfide with M and S in the ratio of 1:1:4, while [La(NH3)9][Cu(S4)2], III, was obtained by reacting La, Cu, and S in the ratio of 1:1:8. In all these compounds, the lanthanide cation is coordinated only by ammonia, while the M+ is chelated by S42- to form metal tetrasulfide rings. [Yb(NH3)8][Cu(S4)2]·NH3 and [Yb(NH3)8][Ag(S4)2]·2NH3 contain [M(S4)2]3- anionic units with M+ in a distorted tetrahedral coordination environment chelated by two S42- groups. Compound III, [La(NH3)9][Cu(S4)2], also contains anionic [Cu(S4)2]3- units; however, Cu+ is in a trigonal planar coordination geometry due to the presence of one monoden...

The reactions of Fe(C0)5 with polysulfides and polyselenides of various chain lengths and stoichiometries were investigated. It was found that Fe(C0)5 must always be present in excess relative to the polychalcogenide chain, or immediate decomposition would result. Conversely, if Fe(C0)5 is present in large excess [Fe3(C0)&3-E)l2(E = S, Se) is formed in excellent yield. This was isolated in very good yield as its [PbP]+ salt. The salt [Ph4P]2[Fe3(CO)90L3-Se], Ib, crystallizes in the triclinic space group Pi; a = 11.580(4) A, b = 12.369(3) A, c = 19.707(4) A, a = 88.18(2)", p = 81.78(2)", y = 71.32(2)", V = 2646(1) A3, Z = 2, R = 0.0322, R, = 0.0358. As the ratio and chain length of polychalcogenide are increased, there is increased oxidation of the iron centers, leading to clusters with formulas [ F ~ ~ ( C O ) I ~ C U ~ E ) ~ ~ ~ and [Fe6(CO)'2E6I2(E = S, Se) successively. The salt [~-BU~N]~[F~~(CO)I~CU~-S)~], 11, crystallizes in the monoclinic space group P211c; a = 33.284(7) A, b = 18.769(4) A, c = 18.704(4) A, p = 90.945(5)", V =11683(10) A3, Z = 8, R = 0.0987, R, = 0.1179. The salt [PkP]*[Fe~(C0)14&3-Se)2], 111, crystallizes in the triclinic space group Pi; a = 12.951(4) A, b = 13.155(6) A, c = 20.729(8) A, a = 98.01(3)", p = 94.25(3)", y = 115.77(3)", V = 3113(2) A3, Z = 2, R = 0.0742, R, = 0.0883. The salt [Et4N]2[Fe6(C0)12Se6], IVb, crystallizes in the monoclinic space group P211c; a = 12.134(2) A, b = 12.753(2) A, c = 16.058(2) A, p = 112.51(2)', V =2348.8(5) A3, Z = 2, R = 0.0307, R, = 0.0335. The cluster [Fes(C0)12E6I2could be used as a [Fe2(C0)6El2transfer group for M(I1) salts, leading to formation of [MFe4(CO)l 2S4J2(M = Ni, Pd). The salt [PkP]2[(Fe2(Co)6CU3-S)2}2Ni]~H2Cl~, Va, crystallizes in the triclinic space group P1; a = 11.270(4) A, b = 12.038(5) A, c = 12.664(5) A, a = 79.53(3)", p = 82.55(3)", y = 89.32(3)", V = 1675(1) A3, Z = 1, R = 0.0543, R, = 0.0699. Cyclic voltammograms were obtained for all these clusters, identifying other stable oxidation states.

A series of polypyridyl ruthenium(II) complexes containing monodentate pyridyl- and cyano-substituted acetylenes have been prepared. Complexes of the type Ru(tpy)(bpy)L{sup 2+} (where tpy = 2,2{prime}:6{prime}:2{double_prime}-terpyridine (C{sub 15}H{sub 11}N{sub 3}), bpy = 2,2{prime}-bipyridine (C{sub 10}H{sub 8}N{sub 2}), and L = pyridine (py) (C{sub 5}H{sub 5}N), pyridylacetylene (PA) (C{sub 7}H{sub 5}N), phenylpyridylacetylene (PPA) (C{sub 10}H{sub 9}N), dipyridylacetylene (DPA) (C{sub 12}H{sub 8}N{sub 2}), CH{sub 3}CN, cyanoacetylene (CA) (C{sub 3}HN), and cyanophenylacetylene (CPA) (C{sub 9}H{sub 5}N)) have been prepared, and their synthesis and characterization are reported herein. The complexes [Ru(tpy)(bpy)(PPA)](PF{sub 6}){sub 2}{center_dot}(CH{sub 3}){sub 2}CO, [Ru(tpy)(bpy)(PA)](PF{sub 6}){sub 2}{center_dot}(CH{sub 3}){sub 2}CO, and [Ru(tpy)(bpy)(CH{sub 3}CN)](PF{sub 6}){sub 2} have been crystallized and the crystal structures determined. [Ru(tpy)(bpy)(CH{sub 3}CN)](PF{sub 6}){sub 2} crystallizes in the monoclinic P2{sub 1}/c space group. [Ru(tpy)(bpy)(PA)](PF{sub 6}){sub 2}{center_dot}(CH{sub 3}){sub 2}CO crystallizes in the triclinic P{bar 1} space group. [Ru(tpy)(bpy)(PPA)](PF{sub 6}){sub 2}{center_dot}(CH{sub 3}){sub 2}CO crystallizes in the triclinic P{bar 1} space group. The inclusion of the functionalized acetylene groups makes these complexes possible precursors to metal-coordinated polyacetylenes.

A new series of materials of the glaserite family with the general formula K(3)RE(VO(4))(2)(RE = Sc, Y, Dy, Ho, Er, Tm, Yb, and Lu) have been hydrothermally synthesized using 10 M K(2)CO(3) at 560 °C and characterized by single crystal X-ray diffraction (XRD), powder XRD, differential thermal analysis/thermogravimetric analysis (DTA/TGA), energy-dispersion X-ray (EDX), Raman, infrared, and absorption spectroscopy. All the compounds crystallize in the trigonal P3̅m1 space group (No. 164), and their structures contain VO(4) tetrahedra, REO(6) octahedra, and two different K(1)O(10) and K(2)O(12) polyhedra. The spectroscopic properties of Nd(3+), Yb(3+), or Er(3+) doped K(3)RE(VO(4))(2) (RE = Y or Lu) are also reported, and the results obtained show that these compounds have promising potential as new laser host materials.

Two new hydrated borates Sr(3)B(6)O(11)(OH)(2) (1) and Ba(3)B(6)O(11)(OH)(2) (2) were hydrothermally synthesized. Their structures were determined by single-crystal X-ray diffraction and further characterized by IR, powder XRD, and DSC/TGA. Compound 1 crystallizes in the triclinic space group P-1 with unit cell parameters of a = 6.6275(13) A, b = 6.6706(13) A, c = 11.393(2) A, α = 91.06(3)°, β = 94.50(3)°, and γ = 93.12(3)°, while compound 2 crystallizes in the noncentrosymmetric monoclinic space group Pc with a = 6.958(14) A, b = 7.024(14) A, c = 11.346(2) A, and β = 90.10(3)°. In spite of the differences in symmetry and packing of the borate chains, both structures consist of the same fundamental building block (FBB) of a [B(6)O(11)(OH)(2)](-6) unit and three unique alkaline earth metal atoms.

Several new hydrated rare earth vanadates and rare earth oxy-vanadates have been synthesized using hydrothermal techniques and characterized using single crystal and powder X-ray diffraction and infrared and UV-vis absorption spectroscopies. The hydrated rare earth vanadates adopt the space group P2(1)/m with general formula A(3)VO(5)(OH)(3) (A = Y (1), Dy (2), or La (3)) and contain anionic distorted square pyramidal [VO(5)](-6) units and AO(7) and AO(8) polyhedra. The oxy-vanadates with the general formula A(2)O(VO(4)) (A = Y (4), Dy (5; 6), or Yb (7)) form two polymorphs in either P2(1)/c or C2/c space groups and contain anionic tetrahedral [VO(4)](-4) units and nonvanadium bonded O(2-) anions in distorted [OA(4)] tetrahedra. In all cases, the vanadium ion is in the tetravalent oxidation state, and its original source was the trace V(4+) impurities in YVO(4). The observed vanadyl and equatorial vanadium-oxygen bond lengths about the square pyramid in compounds 1-3 and the tetrahedral vanadium coordination found in compounds 4-7 are unusual for V(4+). The electronic and vibrational spectra are also reported and correlated with the appropriate coordination environment.

Two new cesium thorium fluorides and three new rubidium thorium fluorides have been synthesized hydrothermally and structurally characterized. The structures of two polymorphs of CsTh(3)F(13) are described in space group P6/mmm with a = 8.2608(14) and c = 8.6519(17) and space group Pmc2(1) with a = 8.1830(16), b = 7.5780(15), and c = 8.6244(17). The analogous orthorhombic compound RbTh(3)F(13), with a = 8.1805(16), b = 7.4378(15), and c = 8.6594(17) in space group Pmc2(1), is also reported. Two other rubidium thorium fluorides are also described: RbTh(2)F(9) crystallizes in the space group Pnma where a = 8.9101(18), b = 11.829(2), and c = 7.4048(15), and Rb(7)Th(6)F(31) crystallizes in the space group R3 where a = 15.609(2) and c = 10.823(2). Comparison of these materials was made on the basis of their structures and synthesis conditions. The formation of these species in hydrothermal fluids appears to be dependent upon the concentration of the alkali fluoride mineralizer solution and, thus, the ratio of alkali ions to thorium in the system.

The reactions of arsenic selenide anionic clusters with M(CO), (M=Mo, W) were investigated and the products characterized by IR and 77 Se NMR spectroscopy and single-crystal X-ray diffraction of bis (n-Bu) 4 N + salts in each case. The reaction of As 4 S 6 2- , with M(CO), generates [M(CO) 2 (As 3 Se 3 ) 2 ] 2- (I) in reasonable yield

The reactions of several arylarsenic dichlorides with the vicinal dithiols HSCH 2 CH(SH)CH 2 OH and meso-HOOCCH(SH)CH(SH)COOH (dimercaptosuccinic acid, were investigated. They readily formed five-membered rings with the dithiolate groups chelated to the arsenic (III) center. The complexes were characterized by a variety of spectroscopic techniques, which indicate that the dithiolates chelate tightly to the arsenic (III) through the sulfur atoms. The complex tolylarsenic dichloride was characterized by single-crystal X-ray diffraction. The cell is monoclinic, of space group P2 1 /n

The title compound can be isolated as well-formed single crystals from the partial solvothermal decomposition of Co(acac)3 in THF/H2O (25:1) at 255 °C. The acetate ligands are presumably derived fr...

A new mixed alkali/alkaline earth iron phosphate, NaBaFe4(HPO4)3.H2O, has been synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction, magnetic susceptibility, infrared spectroscopy, and thermogravimetric analysis. The title compound crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 9.287(2) A, b = 22.665(4) A, c = 8.966(3) A, beta = 91.82(2), and Z = 4. The compound has a 2-D framework structure constructed from layers, stacked along the [010] unit cell direction with Na+ and Ba2+ ions, and water molecules residing within the interlayer space. The anionic layers are composed from the assemblage of vertex shared FeO6 octahedra interconnected by PO4(3)- and HPO4(2)- tetrahedra. The layers are built from four unique FeO6 units linking through vertex shared oxygen atoms to form infinite zigzag chains that run parallel to the a axis. These chains form single layers that run infinitely in the c direction through the vertex sharing of PO4 groups.

The first group 15/16 cationic metal complex [Fe2(Sb2S6)(CO)6][SbF6]2·2SO2 is formed when [S8][Sb2F11]2 is reacted with 3 equiv of iron pentacarbonyl in liquid sulfur dioxide at room temperature. The cationic cluster is formed from an Sb2S6 cage capped on each end through η1-S, η2-S2 bound Fe(CO)3 units. There is a center of inversion at the centroid position of the Sb2S6 cage. The antimony source is apparently the starting anion [Sb2F11]-. This appears to be an unprecedented example of the reaction of a cation with [Sb2F11]-.

The vibrational frequencies associated with the exposed carbon atom in several tetranuclear iron carbide clusters with a butterfly arrangement of atoms were investigated by infrared and Raman spectroscopy. Vibrational assignments were confirmed in most cases by /sup 13/C labeling of the carbide carbon atom. The characteristic feature of the iron butterfly carbides is a readily observed band in the infrared spectrum around 900 cm/sup -1/. An approximate normal-coordinate analysis on these molecules yields values of the metal-carbon force constant of about 250 N m/sup -1/. 29 references, 6 figures, 5 tables.

The high-valent halides MoCl 5 and WCl 6 react readily with a solution of polytelluride anions (Te 3 2− , Te 4 2− , Te 5 2− ) in DMF to form [O=Mo(Te 4 ) 2 ] 2− (Ia) and [O=W(Te 4 ) 2 ] 2− (Ib), respectively, in good yield. The compounds can be isolated as their [(C 6 H 5 ) 4 P] + salts and have been characterized by IR and 125 Te NMR spectroscopy and single-crystal X-ray diffraction. Reaction of the molybdenum oxy telluride cluster with 2 equiv of dimethyl acetylenedicarboxylate results in addition of the acetylene group across both tellurium rings, with formation of the novel bis-(ditellurolene) complex [(C 6 H 5 ) 4 P] 2 [O=Mo(Te 2 C 2 (CO 2 CH 3 ) 2 ) 2 ]•THF ([C 6 H 5 ) 4 P] 2