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The known mineral rodalquilarite, H{sub 3}Fe{sub 2}(TeO{sub 3}){sub 4}Cl, was obtained as high quality single crystals via hydrothermal reactions. This material crystallizes in the triclinic space group P{bar 1}, with cell constants of a = 5.103(2) {angstrom}, b = 6.653(2) {angstrom}, c = 9.012(3) {angstrom}, {alpha} = 73.40(2){degree}, {beta} = 78.03(2), {gamma} = 76.76(2), V = 282.1(2) {angstrom}{sup 3} and was obtained from an NH{sub 4}Cl solution that was heated at 375 C for 4 days. A detailed structural characterization was performed (R = 0.039, R{sub w} = 0.050) and showed that this material is based on layers consisting of edge-sharing FeO{sub 6} octahedra which are interconnected by TeO{sub 3} pyramids which are completed by the presence of a terminal hydrogen atom. Additionally, a second set of TeO{sub 3} pyramids attached to the FeO{sub 6} octahedra are linked across the layers by a shared hydrogen atom. The layers are held together only through these O-H-O interactions and additional weak Te-Cl interactions. In this study, the authors compare this structure to a previous report of rodalquilarite and a reported triclinic form of Fe{sub 2}Te{sub 4}O{sub 11}, which may have been misidentified and is also the title compound. In addition, they havemore » obtained the band gap of this material by diffuse reflectance spectroscopy and find it to be a wide band gap (E{sub g} = 2.51 eV) material. The DC magnetic susceptibility was also obtained and showed that the title compound is antiferromagnetic with a T{sub N} of 29 K.« less

In supercritical CO2, olefin oxidation to epoxides or diols using a Mo(CO)6 catalyst precursor and using t-BuOOH as oxidant proceeds in nearly quantitative yields. The highest yields and fastest rates of diol and epoxide formation were observed with cis-alkenes, while trans-alkenes were considerably less reactive. Phenyl-substituted olefins show a tendency to cleave to their corresponding aldehyde. The use of 70 wt % aqueous solutions of tert-butyl hydroperoxide yield the trans-diol, while anhydrous decane solutions of t-BuOOH give the epoxide. Clearly Mo(CO)6 proved to be the most effective oxygen transfer catalyst for these reactions. Several other oxygen transfer catalysts were tested but proved to be less effective under these conditions. An autoclave equipped with quartz windows allowed for the qualitative determination of a homogeneous reaction environment in the supercritical fluid.

A mixed-valent Fe(II/III) phosphate, NaFe{sub 3.67}(PO{sub 4}){sub 3}, has been synthesized by high-temperature/high-pressure hydrothermal methods and characterized by single-crystal X-ray diffraction, EDAX, magnetic susceptibility, Moessbauer, infrared, and diffuse reflectance spectroscopies, DTA, and bond valence sum calculations. The compound crystallizes in the monoclinic space group C2/c (No. 15) with a = 11.881(4) {angstrom}, b = 12.564(3) {angstrom}, c = 6.522(2) {angstrom}, {beta} = 115.09(2){degree}, V = 881.7(5) {angstrom}{sup 3}, and Z = 4 with R/R{sub w} = 0.029/0.033. It exhibits a three-dimensional channel-like structure with an open framework that is similar to the naturally occurring iron-containing mineral alluaudite, NaFe{sub 3}(PO{sub 4}){sub 3}. In alluaudite there are two distinct channels, one which contains the sodium cations and the second which remains empty. In the title phase, this second channel is partially occupied by a square-planar iron atom. The Moessbauer spectral parameters are consistent with the structure and indicate that the fully occupied iron sites are octahedral Fe(II) and the square-planar iron is Fe(III). Structural comparisons to a number of phosphates and arsenates that also possess the alluaudite-type structure, including NaCu{sub 4}(AsO{sub 4}){sub 3} and NaMn{sub 4}(AsO{sub 4}){sub 3} are discussed.

Allylic alcohols are epoxidized with tert-butyl hydroperoxide in the presence of a vanadyl salen oxo-transfer catalyst in supercritical CO2. The metal catalyst was prepared in a simple two step, Schiff base reaction to form the salen ligand, followed by complexation to the vanadyl group. The epoxidation reactions are clean and give both high yields and good diastereoselectivity.

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 microporous iron (III) phosphate, [H 3 N(CH 2 ) 4 NH 3 ] 3 [Fe 8 (HPO 4 ) 12 (PO 4 ) 2 (H 2 O) 6 ], has been prepared using low temperature hydrothermal methods and characterized by single-crystal X-ray diffraction, EDAX, infrared spectroscopy, thermogravimetric analysis and bond valence sums. The title compound crystallizes as light pink hexagonal-shaped tabs in the centrosymmetric hexagonal space group 3¯ (No.147) with a = b = 13.495(2) A, c = 9.396(2) A, V = 1481.9(4) A 3 and Z = 4 with R/R w = 0.044/0.048. The compound exhibits a complicated three-dimensional microporous structure with quaternary ammonium ions acting as a template for the framework. It is similar to previously reported [HN(CH 2 CH 2 ) 3 NH] 3 [Fe 8 (HPO 4 ) 12 (PO 4 ) 2 (H 2 O) 6 ].

Syntheses of the title compounds were achieved from supercritical amines. The single crystal X-ray characterization of both MAgSe4 (M=Rb, Cs) members indicates that they are isostructural. The structure is built from five membered AgSe4 rings that are stitched together through tetrahedrally coordinated Ag(I) ions to form one dimensional chains running parallel to the a-axis. These chains are separated from each other by the alkali metal cations. Crystal data: orthorhombic, P212121, Z = 4. RbAgSe4: a = 5.809(2), b = 8.927(3), c = 13.435(4) A, U = 698.2(4) A3, and Dc = 4.851 g/cm3. CsAgSe4: a = 5.855(2), b = 9.090(3), c = 13.885(4) A, U = 739.0(4) A3, and Dc = 5.003 g/cm3. The anionic chain found in the title compounds has been observed previously, and comparisons among these phases show that the silver ion coordination in the chain varies as a function of cation size. Both the title compounds are valence precise and optical diffuse reflectance studies show that they are semiconductors with moderately large band gaps.

Five new compounds, which bring together two classical groups, Werner transition-metal hexaammine complexes and sulfosalts, have been prepared from supercritical ammonia. They form in two different structure types which are built from traditional octahedrally coordinated transition-metal hexaammine cations and anionic networks that can be described as metalated derivatives of sulfosalts. The anionic framework of compound I, [Fe(NH3)6]Cu8Sb3S13, is built around a central Cu8S13 core in which copper atoms are surrounded by sulfur atoms in a very distorted tetrahedral coordination. These copper sulfide cores are linked together through bridging antimony atoms which assume a very regular tetrahedral coordination of sulfur atoms. The three mutually orthogonal channels created by the anion are filled with Fe(NH3)6 cations. In [Fe(NH3)6]AgES4 (E = Sb or As), II and III, respectively, the anionic framework is a one-dimensional chain built from alternating E− and Ag−sulfide tetrahedra that share opposite edges. In...

A variety of Diels-Alder reactions have been performed in supercritical water as a reaction medium. The rapid reaction of Diels-Alder reactions of cyclopentadiene and various electron poor dienophiles such as diethyl fumarate and acrylonitrile is observed in supercritical water, and leads to high yields of clean products without added catalysts.

Three new crystalline tin selenide salts have been prepared from the reactions of [PPh4]2[Sn(Se43] in supercritical solvents. The starting material pyrolyzes in supercritical acetonitrile to form [PPh4]4[Sn6Se21] (I), and it also reacts with SnSe in supercritical ammonia leading to a mixture of [PPh4]4[Sn3Se11]2 (II). and [PPh4]2[Sn(Se4)(Se6)2] (III). All three compounds have been characterized by single crystal X-ray diffraction. Crystallographic data: for I, C96H90P4Se21Sn6, space group triclinic, P-1, a = 18.763(3), b = 24.600(4), c = 13.137(1) A , α = 102.63(1), β = 93.66(1), γ = 108.72(1)°, V = 5544(1) A 3 , Z = 2, R = 0.0350, R W = 0.0317: for II , C96H80P4Se22Sn6, space group monoclinic P2 1 /c, a = 31.500(4), b = 16.572(3), c = 22.352(3) A , β = 103.53(1)°, V = 11344(3) A 3 , Z = 4, R = 0.0771, R W = 0.0664: for III , C48H40P2Se16Sn, space group monoclinic, C2/c, a = 25.381(2), b = 13.934(4), c = 19.465(3) A , β = 121.587(8)°, V = 5867(2) A 3 , Z = 4, R = 0.0807, R W = 0.0650 . One of the compounds, [PPh4]2[Sn(Se4(Se62], is a molecular cluster while the other two complexes [PPh4]4[Sn3Se11]2 and [PPh4]4[Sn6Se21], are one dimensional tin selenide chains. The structures of the two chains are related and consits of tetrahedral and distorted trigonal bipyramidal tin(IV) centers bridged by Se2−, Se22− and Se32− chains.

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.

Ba11B26O44(PO4)2 (OH)6 (I) is prepared in low yield by hydrothermal reaction of Ba(OH)2, (NH4)2B10O16, and BaHPO4 in aq.

Single crystals of K2ThF6 (I) and K7Th6F31 (II) are prepared hydrothermally from a mixture of ThF4, KF, and KHF2 (Ag ampoules, autoclave, 575 °C, 3 d).

The crystal structures of the new compounds (V) and (VII) are determined by single crystal XRD.

The alkali hafnium fluorides Li2HfF6 (I), Na5Hf2F13 (II), K2Hf3OF12 (III), K3HfOF5 (IV), and (NH4)3HfOF5 (V) are hydrothermally prepared from aqueous solutions of HfF4, LiF, NaF, KF, KHF2, RbF, or CsF (sealed Ag ampule, autoclave, 400—600 °C, several days).

The title compounds are hydrothermally synthesized from aqueous mixtures of LnVO4 (Ln: Y, Sc, Dy, Ho, Lu, Tm, Yb) and K2CO3 (autoclave, 560 °C, 6 d).

The TaTe 10 3- anion of the title compound, (C 24 H 20 P) 3 [TaTe 10 ].C 3 H 7 NO, consists of an extended 'birdcage' of Te atoms containing an interstitial Ta atom. The Ta atom is seven-coordinate, with Ta-Te distances ranging from 2.753 (3) to 2.870 (3) A, arranged in a distorted capped trigonal prism geometry.

Four new semiconducting quaternary antimony sulfides, KAg 2 SbS 4 (I), K 2 AgSbS 4 (II), RbAg 2 SbS 4 (III), and Rb 2 AgSbS 4 (IV) were prepared in supercritical ammonia at 160°C in 4 days from the appropriate mole ratios of K 2 S 4 , K 2 CO 3 , or Rb 2 CO 3 with Ag, Sb 2 S 3 , and S 8 . Both silver-rich materials, I and III, crystallize in structure types previously observed in BaAg 2 GeS 4 and SrCu 2 SnS 4 , respectively. However, it was determined that the space group of the latter compound was inaccurately reported in the literature. Novel structure types were obtained for II and IV. The structures of I–III contain three-dimensional anionic frameworks, either [Ag 2 SbS 4 ] − or [AgSbS 4 ] 2− , built from a variety of edge- or vertex-shared antimony sulfide and silver sulfide tetrahedra. The alkali metal cations in I and II reside in two orthogonal, intersecting channels, and in three isolated one-dimensional channels in III. Compound IV has a layered structure, with a double layer of rubidium cations separating the neighboring anionic frameworks. It is noteworthy that I–III crystallize in noncentrosymmetric space groups. The structural diversity resulting from the condensation of quite regular SbS 4 and distorted AgS 4 tetrahedra in these four compounds and their optical band gaps are discussed. Crystal data: (I), red polyhedron, tetragonal space group, I 42 m , a = 6.886(1) A, c = 8.438(2) A, V = 400.16(9) A 3 , Z = 2, and R ( wR ) = 0.0397(0.0335); (II), yellow plate, orthorhombic space group, Pnn 2, a = 10.348(2) A, b = 10.522(2) A, c = 7.946(2) A, V = 865.2(3) A 3 , Z = 4, and R ( wR ) = 0.0377(0.0392); (III), yellow-orange needle, trigonal space group, P 3 2 21, a = 6.630(1) A, c = 16.700(2) A, V = 635.8(2) A 3 , Z = 3, and R ( wR ) = 0.0244(0.0310); (IV), yellow polyhedron, monoclinic space group, P 2 1 / n , a = 8.229(3) A, b = 10.857(2) A, c = 10.346(2) A, β = 91.55(2)°, V = 924.0(4) A 3 , Z = 4, and R ( wR ) = 0.0377(0.0405).

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...

Synthetic efforts utilizing Cs2CO3, Ag, M2S3 (M = As, Sb), and S8 in supercritical ammonia (160 °C) have yielded four novel, one-dimensional compounds in the Cs−Ag−M−S system. These members were ch...

A series of ammonothermally grown bulk GaN crystals containing stacking faults has been characterized using structural [transmission electron microscopy (TEM) and synchrotron white-beam x-ray topography (SWBXT)] and optical [low-temperature photoluminescence (PL)] methods. Strong correlations are found between structural and optical properties. In particular, the occurrence of low-temperature PL peaks observed in the 3.30–3.45 eV range correlates with the observation of basal plane stacking faults by TEM (all of which were bounded by Shockley partial dislocations). In addition, the full width at half-maximum of the neutral donor-bound exciton PL peak correlates with the extent of mosaicity revealed on SWBXT Laue patterns recorded from the same crystals.

The electronic properties of ThO2 single crystals were studied using x-ray photoemission spectroscopy (XPS). The XPS results show that the Th 4f core level is in an oxidation state that is consistent with that expected for Th in ThO2. The effective Debye temperature is estimated from the temperature dependent photoemission intensities of the Th 4f core level over the temperature range of 290 to 360 K. A Debye temperature of 468±32 K has been determined.

Single crystals of alkali metal borates for deep UV non-linear applications are grown using the hydrothermal method. Particular emphasis will be placed on the structure and properties of the ABBF category of crystals.

Hydrothermal synthesis of ThO2, UxTh1-xO2, and UOxat temperatures between 670°C and 700°C has been demonstrated. Synthesis at these temperatures is 50-80°C below prior growth studies and represents a new lower bound of successful growth. ThO2single crystals of dimensions 6.49mm x 4.89mm x 3.89 mm and weighing 0.633g have been synthesized at average growth rates near 0.125mm/week. Single crystal UxTh1-xO2crystals with mole fractions up to x≈0.30 have also been grown. The largest alloyed crystal with mole fraction x≈0.23 has dimensions of 2.97mm x 3.23mm x ∼3mm and recorded average growth rates near 0.2mm/week. Four structures were solved from X-ray diffraction data and their crystallographic data reported here. Rocking curve analysis determined a dislocation density of 1.2×109cm-2.

The crystal structures of the new silicate fluorides (IV), (VI), and (VII) are determined by single crystal XRD.

The reactions of the polysulfur and selenium cationic clusters S82+ and Se82+ with various iron carbonyls were investigated. Several new chalcogen containing iron carbonyl cluster cations were isolated, depending on the nature of the counteranion. In the presence of SbF6− as a counterion, the cluster [Fe3(E2)2(CO)10] [SbF6]2·SO2 (E = S, Se) could be isolated from the reaction of E82+ and excess iron carbonyl. The cluster is a picnic-basket shaped molecule of two iron centers linked by two Se2 groups, with the whole fragment capped by an Fe(CO)4 group. Crystallographic data for C10O12Fe3Se4Sb2F12S (I): space group monoclinic P21/c, a = 11.810(9), b = 24.023(6), c = 10.853(7) A, β = 107.15(5)°, V = 2942(3) A3, Z = 4, R = 0.0426, Rw = 0.0503. When Sb2F11− is present as the counterion, or Se4[Sb2F11]2 is used as the cluster cation source, a different cluster can be isolated, which has the formula [Fe4(Se2)3(CO)12] [SbF6]2·3SO2. The dication contains two Fe2Se2 fragments bridged by an Se2 group. Crystallographic data for C12O18Fe4Se6Sb2F12S3 (III): space group triclinic P1, a = 10.941(4), b = 18.400(9), c = 10.253(4) A, α = 93.10(4), β = 103.74(3), γ = 93.98(3)°, V = 1995(1) A3, Z = 2, R = 0.0328, Rw = 0.0325. The CO stretches in the IR spectrum all show a large shift to higher wavenumbers, suggesting almost no τ backbonding from the metals. This also correlates with the observed bond distances. All the compounds are extremely sensitive to air and water, and readily lose SO2 when removed from the solvent. Thus all the crystals were handled at −100°C. The clusters seem to be either insoluble or unstable in all solvents investigated.

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.

Polar crystals provide an interesting avenue for materials research both in the structures they form and the properties they possess. This work describes the hydrothermal synthesis and structural characterization of three novel silicate fluorides. Compound (1), LiY 3(SiO 4) 2F 2 crystallizes in space group C2/c, with a=17.651(4) Å, b=4.8868(10) Å, c=11.625(2) Å and β=131.13(3)°. BaY 2(Si 2O 7)F 2 (2) crystallizes in space group P-1, with a=5.1576(10) Å, b=6.8389(14) Å, c=11.786(2) Å, α=93.02(3)°, β=102.05(3)° and γ=111.55(3) °. Finally, the structure of Ba 2Y 3(SiO 4) 2F 5 (3) was determined in the polar orthorhombic space group Pba2, having unit cell parameters a=8.8864(18) Å, b=12.764(3) Å and c=5.0843(10) Å. The structures are compared based on their building blocks and long range polarities. Aligned silicate tetrahedra segregated into a single layer in (3) impart the observed polarity., The National Science Foundation (DMR-0907395)

Three new polymorphs of CsThF5 are hydrothermally synthesized from ThF4 and aqueous CsF solutions of varying concentrations in a silver ampule (autoclave, 575 °C, 2—12 d).

Sr3B6O11(OH)2 (I) is synthesized by solid state reaction of LiOH, B2O3, Sr(OH)2, and KOH (Pt crucible, 900 °C in air, 16 h) followed by reaction of the obtained product with aqueous SrCl2 solution (autoclave, 560 °C, 6 d, 90% yield).

Crystals of the new title compounds are synthesized by solid state reactions of MF2 (M: Sr, Ba), H3BO3, and NH4F (Pt crucible, 800 °C, 24 h) followed by hydrothermal reaction of the obtained powders with aqueous solutions of KF (for M: Sr) or KHF2 (for M: Ba) at 540 °C (welded silver ampules, 7 d).

New hydrated rare earth vanadates and rare earth oxy-vanadates are characterized by powder and single crystal XRD, and UV/VIS spectroscopy.

The hydrothermal crystal growth technique is developed for the growth of epitaxial single crystal layers on YAG. High quality epitaxial layers of functionalized layers can be grown using Y2O3 doped with the desired ion and Al2O3 as feedstocks in water between 600-650°C at 1 kbar pressure, with a mineralizer of 1-4M K2CO3.The epitaxial layers are doped with a variety of doping ions that enable a number of optical functionalities. These include undoped regions to serve as endcaps, Q-switching regions, ASE suppression cladding layers, waveguide layers and a number of other applications. Different layers can be grown sequentially on the same crystal to create multifunctional single crystals. Epitaxial layers have been grown on both {111} and {100} faces with rates of growth being {100}>{111}>{110}. Growth rates range typically from 25 to 100 microns per day but faster and slower rates have been observed. The technique is not restricted to YAG and can be extended to any oxide hosts that can be grown hydrothermally. Work is being extended to LuAG, YVO4 and M2O3 (M = Lu, Sc).The techniques presented here can address long-standing performance issues associated with solid-state laser materials; when combined with crystal joining technologies, new crystal functionalities emerge that can further improve solid-state laser performance; we refer to this new generation of laser crystals as "smart".

Cryogenic Yb:YAG lasers operating at 1029 nm have been demonstrated at Snake Creek Lasers with high average power CW and ultrafast output powers, and provide near diffraction-limited output beams that are ideal for applications in harmonic generation. We describe experiments that have produced high average power green output power at 515 nm as well as preliminary experiments producing UV output power at 257.25 nm. Frequency doubling experiments used a 20 mm long non-critically phase-matched LBO crystal mounted in a constant temperature oven. A mode-locked Yb fiber laser operating at 50 MHz was used to drive a two Yb:YAG cryogenic amplifier system, producing hundreds of watts of average power output with a FWHM pulsewidth of 12 ps. Doubling efficiencies of > 50 % have been observed. For frequency quadrupling, we have used hydrothermally grown KTTP crystals grown at Clemson University and Advanced Photonic Crystals. KBBF offers unprecedented UV transmission down to 155 nm, and was used in a Type I phasematching configuration. The properties of KBBF will be discussed, as well as the experimental results observed and conversion efficiency.

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.

The new compounds (III) and (V)—(VII) are structurally characterized using powder and single crystal XRD.

Three novel hydrated borates Ba2B5O9(OH) (1), Sr2B5O9(OH) (2) and Li2Sr8B22O41(OH)2 (3) have been synthesized hydrothermally and their structures determined. Compounds (1) and (2) are isostructural, crystallizing in space group P21/c and having lattice parameters of a=6.6330(13) A, b=8.6250(17) A, c=14.680(3) A, β=93.46(3)° and a=6.4970(13) A, b=8.4180(17) A, c=14.177(3) A, β=94.35(3)°, respectively. Compound (3) crystallizes in P-1 with lattice parameters of a=6.4684(13) A, b=8.4513(17) A, c=14.881(3) A, α=101.21(3)°, β=93.96(3)°, γ=90.67(3)°. While similar in their axis lengths, (3) differs greatly in structure and formulation from (1) and (2). The structure of (1) and (2) is contrasted to that of the well-known mineral hilgardite (Ca2B5O9Cl·H2O).

Hydrothermal methods have been developed for the growth of YAG and LuAG single crystals. This technique allows for the growth of single crystals having multiple layers of optical functionality. Several preliminary examples are described.

This review describes the chemistry of anionic mixed 1516 clusters and their coordination chemistry with transition metals. The focus is on the heavier elements such as sulfides and selenides of phosphorus, arsenic and antimony. A brief introduction with a historical perspective is followed by the chemistry of soluble anionic clusters, including preparative methods and structural characteristics. Solids containing recognizable anionic fragments (Zintl phases) are also described. Bonding is mentioned briefly. Transition metal complexes of these clusters are discussed in some detail and structures and bonding are highlighted. Neglected areas and future prospects are mentioned.

The reaction of [HFe(CO)4]− with various binary antimony selenides was investigated. In the presence of Sb2Se3 the organometallic anion acts as a reducing agent leading to formation of [Sb4Se6]2- which has a crown shaped geometry with a transannular Sb-Sb bond. Reaction with Sb2Se5 leads to incorporation of iron carbonyl with formation of a dimer of formula [Fe2(CO)4(SbSe4)2]2-. The cluster contains two Fe(CO)2 fragments bridged by SbSe4 3- units. The main group anions are not tetrathiometallates, but rather a trivalent Sb bound to two selenides and a diselenide. Both compounds were structurally characterized as their [PPh4]+ salts. Crystal data for [PPh4]2[Sb4Se6], triclinic, P-1, a = 10.124(2)A, b = 14.670(2)A, c = 17.352(2)A, α = 96.42(2)˚, β = 95.78(2)˚, γ = 97.09(2)˚, V = 2524.2(7)A3, Z = 2, R = 0.0377, Rw = 0.0465; crystal data for [PPh4]2[Fe2(CO)4(SbSe4)2], monoclinic, P21/n, a = 15.552(5)A, b = 110.279(3)A, c = 18.159(6)A, β = 101.72(3)˚, V = 2819(1)A3, Z = 2, R = 0.0372, Rw = 0.0395.

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 title compounds are synthesized hydrothermally under supercritical conditions from aqueous solutions of B2O3, Sr(OH)2 or Ba(OH)2, and BeO using NaOH as mineralizer (autoclave, 565 °C, 5 d, about 5% yield).

Crystals of Ba2TiSi2O8, Sr2TiSi2O8 (about 10% yield), Ba2VSi2O8, and Ba2TiGe2O8 belonging to the fresnoite family are hydrothermally prepared from aqueous solutions of Ba(OH)2 or Sr(OH)2, TiO2 or VO2, SiO2 or GeO2, and CsOH or KOH (silver ampules, autoclave, 500 °C, 5 d).

KNbO3 (I), KTaO3 (II), and KTa0.56Nb0.44O3 (III) are prepared by solid state reactions of appropriate mixtures of K2CO3 and Ta2O5 and/or Nb2O5 (950 °C, 72 h).

Structures of the tetraphenylphosphonium salts of 2-telluro-5-methylthiophene and its mercury(II) metal complex, 2-tris(5-methyl-2-thienyltelluro)mercury(II) have been determined. Both compounds have ionic structures, with no close contacts between ions. The metal complex consists of three 2-telluro-5-methylthiophene ligands bound through the tellurium atoms in a trigonal-planar arrangement about the mercury(II) metal center. Addition of the methyl substituent to the thiophene ring avoids the rotational disorder which can occur upon complexation of the parent ion, 2-tellurothiophene