Structural and spectroscopic trends in actinyl iodates of uranium,neptunium, and plutonium

Two neptunyl(VI) iodates, NpO(2)(IO(3))(2)(H(2)O) (1) and NpO(2)(IO(3))(2).H(2)O (2), have been prepared from the aqueous reactions of Np(V) in HCl with KIO(4) or H(5)IO(6) at 180 degrees C and have been characterized by single crystal X-ray diffraction and Raman spectroscopy. Both compounds consist of two-dimensional arrangements of pentagonal bipyramidal [NpO(7)] polyhedra with axial neptunyl, NpO(2)(2+), dioxocations. In 1, the neptunium centers are bound in the equatorial plane by four bridging iodate anions and one terminal water molecule. The iodate anions link the [NpO(7)] units into corrugated sheets that interact with one another through intermolecular IO(3)(-)...IO(3)(-) interactions as also observed in UO(2)(IO(3))(2)(H(2)O). Compound 2 is isostructural with the recently reported PuO(2)(IO(3))(2).H(2)O, where oxygen atoms from bridging iodate anions occupy the five equatorial sites around the neptunyl moieties. The iodate anions occur as both mu(2)- and mu(3)-units and link the neptunyl polyhedra into sheets. Both types of iodate anions have their stereochemically active lone-pair of electrons aligned on one side of each layer creating a polar structure. Raman spectra of 1, UO(2)(IO(3))(2)(H(2)O), and PuO(2)(IO(3))(2).H(2)O show a sequential shift of the nu(1)(AnO(2)(2+)) stretch to lower wavenumber as the atomic number of the actinide is increased. Crystallographic data: 1, orthorhombic, space group Pcan, a = 7.684(2) A, b = 8.450(2) A, c = 12.493(3) A, Z = 4; 2, orthorhombic, space group Pna2(1), a = 7.314(1) A, b = 11.631(2) A, c = 9.449(2) A, Z = 4.     

Hydrothermal synthesis and structure of a new one-dimensional, mixed-metal U(VI) iodate, Cs(2)[(UO(2))(CrO(4))(IO(3))(2)

The reaction of the molecular transition metal iodate, Cs[CrO(3)(IO(3))], with UO(3) under mild hydrothermal conditions provides access to a new low-dimensional, mixed-metal U(VI) compound, Cs(2)[(UO(2))(CrO(4))(IO(3))(2)] (1). The structure of 1 is quite unusual and consists of one-dimensional (1)(infinity)[(UO(2))(CrO(4))(IO(3))(2)](2-) ribbons separated by Cs(+) cations. These ribbons are formed from [UO(7)] pentagonal bipyramids that contain a uranyl core, [CrO(4)] tetrahedra, and both monodentate and bridging iodate anions. Crystallographic data: 1, monoclinic, space group P2(1)/n, a = 7.3929(5) A, b = 8.1346(6) A, c = 22.126(2) A, beta = 90.647(1) degrees, Z = 4 (T = 193 K).     

A series of new alkali metal indium iodates with isolated or extended anions

Systematic explorations of new phases in the A(I)-In(III)-I(V)-O system by hydrothermal reactions led to five new compounds, namely, AIn(IO(3))(4) (A = Li, Na), Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs). The structure of AIn(IO(3))(4) (A = Li, Na) contains one-dimensional [In(IO(3))(4)](-) chains separated by Li(+) or Na(+) cations. In both compounds, each In(3+) cation is octahedrally coordinated by six IO(3)(-) anions, neighboring In(3+) cations are interconnected by bidentate bridging iodate anions into 1D chains. The structures of Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs) all feature isolated [In(IO(3))(6)](3-) anions with alkali metal ions (and H(+) ions) as spacers. Both optical diffuse reflectance spectrum measurements and band structure calculations based on DFT methods indicate that LiIn(IO(3))(4), NaIn(IO(3))(4), and Rb(2)HIn(IO(3))(6) are insulators.     

Bi2(IO4)(IO3)3: a new potential infrared nonlinear optical material containing [IO4](3-) anion

A new potential infrared (IR) nonlinear optical (NLO) material Bi(2)(IO(4))(IO(3))(3) was synthesized by hydrothermal method. Bi(2)(IO(4))(IO(3))(3) crystallizes in the chiral orthorhombic space group P2(1)2(1)2(1) (No. 19) with a = 5.6831(11) ?, b = 12.394(3) ?, and c = 16.849(3) ?. It exhibits a three-dimensional framework through a combination of the IO(3), IO(4), BiO(8), and BiO(9) polyhedra and is the first noncentrosymmetric (NCS) structure containing [IO4](3-) anion. Bi(2)(IO(4))(IO(3))(3) has an IR cutoff wavelength of 12.3 μm and belongs to the type 1 phase-matchable class with a moderately large SHG response of 5 × KDP, which is in good agreement with the theoretical calculations.     

Excision of uranium oxide chains and ribbons in the novel one-dimensional uranyl iodates K(2)[(UO(2))3(IO(3))(4)O(2)] and Ba[(UO(2)2(IO(3))(2)O(2)](H(2)O)

The alkali metal and alkaline-earth metal uranyl iodates K(2)[(UO(2))(3)(IO(3))(4)O(2)] and Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) have been prepared from the hydrothermal reactions of KCl or BaCl(2) with UO(3) and I(2)O(5) at 425 and 180 degrees C, respectively. While K(2)[(UO(2))(3)(IO(3))(4)O(2)] can be synthesized under both mild and supercritical conditions, the yield increases from <5% to 73% as the temperature is raised from 180 to 425 degrees C. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), however, has only been isolated from reactions performed in the mild temperature regime. Thermal measurements (DSC) indicate that K(2)[(UO(2))(3)(IO(3))(4)O(2)] is more stable than Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) and that both compounds decompose through thermal disproportionation at 579 and 575 degrees C, respectively. The difference in the thermal behavior of these compounds provides a basis for the divergence of their preparation temperatures. The structure of K(2)[(UO(2))(3)(IO(3))(4)O(2)] is composed of [(UO(2))(3)(IO(3))(4)O(2)](2)(-) chains built from the edge-sharing UO(7) pentagonal bipyramids and UO(6) octahedra. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) consists of one-dimensional [(UO(2))(2)(IO(3))(2)O(2)](2)(-) ribbons formed from the edge sharing of distorted UO(7) pentagonal bipyramids. In both compounds the iodate groups occur in both bridging and monodentate binding modes and further serve to terminate the edges of the uranium oxide chains. The K(+) or Ba(2+) cations separate the chains or ribbons in these compounds forming bonds with terminal oxygen atoms from the iodate ligands. Crystallographic data: K(2)[(UO(2))(3)(IO(3))(4)O(2)], triclinic, space group P_1, a = 7.0372(5) A, b = 7.7727(5) A, c = 8.9851(6) A, alpha = 93.386(1) degrees, beta = 105.668(1) degrees, gamma = 91.339(1) degrees, Z = 1; Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), monoclinic, space group P2(1)/c, a = 8.062(4) A, b = 6.940(3) A, c = 21.67(1), beta= 98.05(1) degrees, Z = 4.     

Mixed-metal uranium(VI) iodates: hydrothermal syntheses,structures, and reactivity of Rb[UO(2)(CrO(4))(IO(3))(H(2)O)], A(2)[UO(2)(CrO(4))(IO(3))(2)] (A = K,Rb, Cs), and K(2)[UO(2)(MoO(4))(IO(3))(2)

The reactions of the molecular transition metal iodates A[CrO(3)(IO(3))] (A = K, Rb, Cs) with UO(3) under mild hydrothermal conditions provide access to four new, one-dimensional, uranyl chromatoiodates, Rb[UO(2)(CrO(4))(IO(3))(H(2)O)] (1) and A(2)[UO(2)(CrO(4))(IO(3))(2)] (A = K (2), Rb (3), Cs (4)). Under basic conditions, MoO(3), UO(3), and KIO(4) can be reacted to form K(2)[UO(2)(MoO(4))(IO(3))(2)] (5), which is isostructural with 2 and 3. The structure of 1 consists of one-dimensional[UO(2)(CrO(4))(IO(3))(H(2)O)](-) ribbons that contain uranyl moieties bound by bridging chromate and iodate anions as well as a terminal water molecule to create [UO(7)] pentagonal bipyramidal environments around the U(VI) centers. These ribbons are separated from one another by Rb(+) cations. When the iodate content is increased in the hydrothermal reactions, the terminal water molecule is replaced by a monodentate iodate anion to yield 2-4. These ribbons can be further modified by replacing tetrahedral chromate anions with MoO(4)(2)(-) anions to yield isostructural, one-dimensional [UO(2)(MoO(4))(IO(3))(2)](2)(-) ribbons. Crystallographic data: 1, triclinic, space group P(-)1, a = 7.3133(5) A, b = 8.0561(6) A, c = 8.4870(6) A, alpha = 88.740(1) degrees, beta = 87.075(1) degrees, gamma = 71.672(1) degrees, Z = 2; 2, monoclinic, space group P2(1)/c, a = 11.1337(5) A, b = 7.2884(4) A, c = 15.5661(7) A, beta = 107.977(1) degrees, Z = 4; 3, monoclinic, space group P2(1)/c, a = 11.3463(6) A, b = 7.3263(4) A, c = 15.9332(8) A, beta = 108.173(1) degrees, Z = 4; 4, monoclinic, space group P2(1)/n, a = 7.3929(5) A, b = 8.1346(6) A, c = 22.126(2) A, beta = 90.647(1) degrees, Z = 4; 5, monoclinic, space group P2(1)/c, a = 11.3717(6) A, b = 7.2903(4) A, c = 15.7122(8) A, beta = 108.167(1) degrees, Z = 4.     

Self-assembly of a polar open-framework uranyl vanadyl hexaoxoiodate(VII) constructed entirely from distorted octahedral building units in the first uranium hexaoxoiodate: K2[(UO2)2(VO)2(IO6)2O].H2O

The reaction of UO(3) with V(2)O(5) and KIO(4) under mild hydrothermal conditions produces K(2)[(UO(2))(2)(VO)(2)(IO(6))(2)O].H(2)O (1) in the form of orange acicular crystals. The structure of 1 consists of UO(6), VO(6), and IO(6) distorted octahedra that are assembled into a polar, open-framework structure. The distorted VO(6) and IO(6) octahedra edge-share to form chains that run down the c-axis. Each VO(6) octahedron also shares a vertex with an adjacent vanadium atom to link the chains together into a ribbon. The IO(6) units also partake in corner-sharing with the UO(6) units to create interconnected elliptical tubes. The major channels in 1 are filled with K(+) cations and water molecules. The polarity of this compound is caused by alignment of distorted vanadyl hexaoxoiodate ribbons and UO(6) trapezoidal bipyramids resulting in a large second-harmonic generation response of 300 times that of alpha-quartz. Crystallographic data: 1, orthorhombic, space group Pba2, a = 9.984(2) A, b = 16.763(3) A, c = 4.977(1) A, Z = 4 (T = 193 K).     

Further evidence for the tetraoxoiodate(V) anion,IO(4)(3-): hydrothermal syntheses and structures of Ba[(MoO(2))(6)(IO(4))(2)O(4)] x H(2)O and Ba(3)[(MoO(2))(2)(IO(6))(2)] x 2H(2)O

The hydrothermal reaction of MoO(3) with BaH(3)IO(6) at 180 degrees C for 3 days results in the formation of Ba[(MoO(2))(6)(IO(4))(2)O(4)] x H(2)O (1). Under similar conditions, the reaction of Ba(OH)(2) x 8H(2)O with MoO(3) and Ba(IO(4))(2) x 6H(2)O yields Ba(3)[(MoO(2))(2)(IO(6))(2)] x 2H(2)O (2). The structure of 1, determined by single-crystal X-ray diffraction, consists of corner- and edge-sharing distorted MoO(6) octahedra that create two-dimensional slabs. Contained within this molybdenum oxide framework are approximately C(2v) tetraoxoiodate(V) anions, IO(4)(3-), that are involved in bonding with five Mo(VI) centers. The two equatorial oxygen atoms of the IO(4)(3-) anion chelate a single Mo(VI) center, whereas the axial atoms are mu(3)-oxo groups and complete the octahedra of four MoO(6) units. The coordination of the tetraoxoiodate(V) anion to these five highly electropositive centers is probably responsible for stabilizing the substantial anionic charge of this anion. The Ba(2+) cations separate the layers from one another and form long ionic contacts with neighboring oxygen atoms and a water molecule. Compound 2 also contains distorted MoO(6) octahedra. However, these solely edge-share with octahedral hexaoxoiodate(VII), IO(6)(5-), anions to form zigzagging one-dimensional, (1)(infinity)[(MoO(2))(IO(6))](3-), chains that are polar. These chains are separated from one another by Ba(2+) cations that are coordinated by additional water molecules. Bond valence sums for the iodine atoms in 1 and 2 are 5.01 and 7.03, respectively. Crystallographic data: 1, monoclinic, space group C2/c, a = 13.584(1) A, b = 7.3977(7) A, c = 20.736(2) A, beta = 108.244(2) degrees, Z = 4; 2, orthorhombic, space group Fdd2, a = 13.356(7) A, b = 45.54(2) A, c = 4.867(3) A, Z = 8.     

Synthesis, structure, and spectroscopic properties of Am(IO3)3 and the photoluminescence behavior of Cm(IO3)3

We have prepared Am(IO(3))(3) as a part of our continuing investigations into the chemistry of the 4f- and 5f-elements' iodates. Single crystals were obtained from the reaction of Am(3+) and H(5)IO(6) under mild hydrothermal conditions. Crystallographic data on an eight-day-old crystal are (21 degrees C, Mo Kalpha, lambda = 0.71073 Angstroms): monoclinic, space group P2(1)/c, a = 7.2300(5) Angstroms, b = 8.5511(6) Angstroms, c = 13.5361(10) Angstroms, beta = 100.035(1) degrees, V = 824.06(18), Z = 4. The structure consists of Am(3+) cations bound by iodate anions to form [Am(IO(3))(8)] units, where the local coordination environment around the americium centers is a distorted dodecahedron. There are three crystallographically unique iodate anions within the structure that bridge in both bidentate and tridentate fashions to form the overall three-dimensional structure. Repeated collection of X-ray diffraction data with time for a crystal of (243)Am(IO(3))(3) revealed an anisotropic expansion of the unit cell, presumably from self-irradiation damage, to generate values of a = 7.2159(7) Angstroms, b = 8.5847(8) Angstroms, c = 13.5715(13) Angstroms, beta = 99.492(4) degrees, V = 829.18(23) after approximately five months. The Am(IO(3))(3) crystals have also been characterized by Raman spectroscopy and the spectral results compared to those for Cm(IO(3))(3). Three strong Raman bands were observed for both compounds and correspond to the I-O symmetric stretching of the three crystallographically distinct iodate anions. The Raman profile suggests a lack of interionic vibrational coupling of the I-O stretching, while intraionic coupling provides symmetric and asymmetric components that correspond to each iodate site. Photoluminescence data for both Am(IO(3))(3) and Cm(IO(3))(3) are reported here for the first time. Assignments for the electronic levels of the actinide cations were based on these photoluminescence measurements and indicate the presence of vibronic coupling between electronic transitions and IO(3)(-) vibrational modes in both compounds.     

Explorations of new second-order nonlinear optical materials in the potassium vanadyl iodate system

Four new potassium vanadyl iodates based on lone-pair-containing IO(3) and second-order Jahn-Teller distorted VO(5) or VO(6) asymmetric units, namely, α-KVO(2)(IO(3))(2)(H(2)O) (Pbca), β-KVO(2)(IO(3))(2)(H(2)O) (P2(1)2(1)2(1)), K(4)[(VO)(IO(3))(5)](2)(HIO(3))(H(2)O)(2)·H(2)O (P1), and K(VO)(2)O(2)(IO(3))(3) (Ima2) have been successfully synthesized by hydrothermal reactions. α-KVO(2)(IO(3))(2)(H(2)O) and β-KVO(2)(IO(3))(2)(H(2)O) exhibit two different types of 1D [VO(2)(IO(3))(2)](-) anionic chains. Neighboring VO(6) octahedra in the α-phase are corner-sharing into a 1D chain with the IO(3) groups attached on both sides of the chain in a uni- or bidentate bridging fashion, whereas those of VO(5) polyhedra in the β-phase are bridged by IO(3) groups into a right-handed helical chain with remaining IO(3) groups being grafted unidentately on both sides of the helical chain. The structure of K(4)[(VO)(IO(3))(5)](2)(HIO(3))(H(2)O)(2)·H(2)O contains novel isolated [(VO)(IO(3))(5)](2-) units composed of one VO(6) octahedron linked to five IO(3) groups and one terminal O(2-) anion. The structure of K(VO)(2)O(2)(IO(3))(3) exhibits a 1D [(VO)(2)O(2)(IO(3))(3)](-) chain in which neighboring VO(6) octahedra are interconnected by both oxo and bridging iodate anions. Most interestingly, three of four compounds are noncentrosymmetric (NCS), and K(VO)(2)O(2)(IO(3))(3) displays a very strong second-harmonic generation response of about 3.6 × KTP, which is phase matchable. It also has high thermal stability, a wide transparent region and moderate hardness as well as an excellent growth habit. Thermal analyses and optical and ferroelectric properties as well as theoretical calculations have also been performed.     

ZnIO3(OH): a new layered noncentrosymmetric polar iodate--hydrothermal synthesis, crystal structure, and second-harmonic generating (SHG) properties

A new noncentrosymmetric polar iodate material, ZnIO(3)(OH), has been hydrothermally synthesized as crystals and pure powders by using ZnO (or Zn(CH(3)CO(2))(2)·2H(2)O), HIO(3), and water. Single crystal X-ray diffraction was used to determine the crystal structure of the reported material. ZnIO(3)(OH) exhibits a layered structure that is composed of ZnO(6) and IO(3) polyhedra. Powder nonlinear optical (NLO) properties measurements on ZnIO(3)(OH) using 1064 nm radiation indicate the material has a second-harmonic generating (SHG) efficiency of approximately 20 times that of α-SiO(2). Additional SHG measurements reveal that the material is not phase-matchable (type 1). Infrared spectroscopy, elemental analysis, and thermogravimetric analysis for the reported compound are also presented. Crystal data: ZnIO(3)(OH), monoclinic, space group Cc (no. 9) with a = 4.67670(10) ?, b = 11.2392(4) ?, c = 6.3308(2) ?, β = 90.019(2)°, and Z = 4.     

Synthesis and Characterization by (19)F and (125)Te NMR and Raman Spectroscopy of cis-ReO(2)(OTeF(5))(3) and cis-ReO(2)(OTeF(5))(4)(-), and X-ray Crystal Structure of [N(CH(3))(4)(+)][cis-ReO(2)(OTeF(5))(4)(-)

The pentafluorooxotellurate compound ReO(2)(OTeF(5))(3) has been synthesized from the reaction of ReO(2)F(3) with B(OTeF(5))(3) and structurally characterized in solution by (19)F and (125)Te NMR spectroscopy and in the solid state by Raman spectroscopy. The NMR and vibrational spectroscopic findings are consistent with a trigonal bipyramidal arrangement in which the oxygen atoms and an OTeF(5) group occupy the equatorial plane. The (19)F and (125)Te NMR spectra show that the axial and equatorial OTeF(5) groups of ReO(2)(OTeF(5))(3) are fluxional and are consistent with intramolecular exchange by means of a pseudorotation. The Lewis acid behavior of ReO(2)(OTeF(5))(3) is demonstrated by reaction with OTeF(5)(-). The resulting cis-ReO(2)(OTeF(5))(4)(-) anion was characterized as the tetramethylammonium salt in solution by (19)F and (125)Te NMR spectroscopy and in the solid state by Raman spectroscopy and X-ray crystallography. The compound crystallizes in the triclinic system, space group P&onemacr;, with a = 13.175(7) ?, b = 13.811(5) ?, c = 15.38(1) ?, alpha = 72.36(5)(o), beta = 68.17(5)(o), gamma = 84.05(4)(o), V = 2476(2) ?(3), D(calc) = 3.345 g cm(-)(3), Z = 4, R = 0.0547. The coordination sphere about Re(VII) in cis-ReO(2)(OTeF(5))(4)(-) is a pseudooctahedron in which the Re-O double bond oxygens are cis to one another.     

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.     

Synthesis and characterization of fluorinated metal arsenates with a layer structure: (C4H12N2)(1.5)[M3F5(HAsO4)2(AsO4)] (M = Fe, Ga)

Two fluorinated metal arsenates, (C(4)H(12)N(2))(1.5)[M(3)F(5)(HAsO(4))(2)(AsO(4))] (M = Fe, Ga), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, magnetic susceptibility, M?ssbauer spectroscopy, and (71)Ga NMR spectroscopy. The two compounds are isostructural and crystallize in the monoclinic space group P2(1)/c (No. 14) with a = 8.394(1) A, b = 21.992(3) A, c = 10.847(1) A, beta = 96.188(2) degrees, and Z = 4 for the Fe compound, and a = 8.398(1) A, b = 21.730(3) A, c = 10.679(1) A, beta = 95.318(2) degrees, and Z = 4 for the Ga compound. The structure consists of infinite chains of corner-sharing MX(6) (X = O, F) octahedra and dimers of edge-sharing MO(3)F(3) octahedra, which are linked into two-dimensional sheets through arsenate tetrahedra with diprotonated piperazinium cations between the sheets. Magnetic susceptibility and M?ssbauer spectroscopy confirm the presence of Fe(III). The (71)Ga MAS NMR spectrum clearly shows a line shape consisting of three components, corresponding to three crystallographically distinct Ga sites.     

Synthesis and characterization of six new quaternary actinide thiophosphate compounds: Cs(8)U(5)(P(3)S(10))(2)(PS(4))(6)(,) K(10)Th(3)(P(2)S(7))(4)(PS(4))(2), and A(5)An(PS(4))(3), (A = K, Rb, Cs; An = U, Th)

Six new actinide metal thiophosphates have been synthesized by the reactive flux method and characterized by single-crystal X-ray diffraction: Cs(8)U(5)(P(3)S(10))(2)(PS(4))(6) (I), K(10)Th(3)(P(2)S(7))(4)(PS(4))(2) (II), K(5)U(PS(4))(3) (III), K(5)Th(PS(4))(3) (IV), Rb(5)Th(PS(4))(3) (V), and Cs(5)Th(PS(4))(3) (VI). Compound I crystallizes in the monoclinic space group P2(1)/c with a = 33.2897(1) A, b = 14.9295(1) A, c = 17.3528(2) A, beta = 115.478(1) degrees, Z = 8. Compound II crystallizes in the monoclinic space group C2/c with a = 32.8085(6) A, b = 9.0482(2) A, c = 27.2972(3) A, beta = 125.720(1) degrees, Z = 8. Compound III crystallizes in the monoclinic space group P2(1)/c with a = 14.6132(1) A, b = 17.0884(2) A, c = 9.7082(2) A, beta = 108.63(1) degrees, Z = 4. Compound IV crystallizes in the monoclinic space group P2(1)/n with a = 9.7436(1) A, b = 11.3894(2) A, c = 20.0163(3) A, beta = 90.041(1) degrees, Z = 4, as a pseudo-merohedrally twinned cell. Compound V crystallizes in the monoclinic space group P2(1)/c with a = 13.197(4) A, b = 9.997(4) A, c = 18.189(7) A, beta = 100.77(1) degrees, Z = 4. Compound VI crystallizes in the monoclinic space group P2(1)/c with a = 13.5624(1) A, b = 10.3007(1) A, c = 18.6738(1) A, beta = 100.670(1) degrees, Z = 4. Optical band-gap measurements by diffuse reflectance show that compounds I and III contain tetravalent uranium as part of an extended electronic system. Thorium-containing compounds are large-gap materials. Raman spectroscopy on single crystals displays the vibrational characteristics expected for [PS(4)](3)(-), [P(2)S(7)](4-), and the new [P(3)S(10)](5)(-) building blocks. This new thiophosphate building block has not been observed except in the structure of the uranium-containing compound Cs(8)U(5)(P(3)S(10))(2)(PS(4))(6).     

Methyl Tin(IV) derivatives of HOTeF(5) and HN(SO(2)CF(3))(2): a solution multinuclear NMR study and the X-ray crystal structures of (CH(3))(2)SnCl(OTeF(5)) and [(CH(3))(3)Sn(H(2)O)(2)][N(SO(2)CF(3))(2)

The new tin(IV) species (CH(3))(2)SnCl(OTeF(5)) was prepared via either the solvolysis of (CH(3))(3)SnCl in HOTeF(5) or the reaction of (CH(3))(3)SnCl with ClOTeF(5). It was characterized by NMR and vibrational spectroscopy, mass spectrometry, and single crystal X-ray diffraction. (CH(3))(2)SnCl(OTeF(5)) crystallizes in the monoclinic space group P2(1)/n (a = 5.8204(8) A, b =10.782(1) A, c =15.493(2) A, beta = 91.958(2) degrees, V = 971.7(2) A(3), Z = 4). NMR spectroscopy of (CH(3))(3)SnX, prepared from excess Sn(CH(3))(4) and HX (X = OTeF(5) or N(SO(2)CF(3))(2)), revealed a tetracoordinate tin environment using (CH(3))(3)SnX as a neat liquid or in dichloromethane-d(2) (CD(2)Cl(2)) solutions. In acetone-d(6) and acetonitrile-d(3) (CD(3)CN) solutions, the tin atom in (CH(3))(3)SnOTeF(5) was found to extend its coordination number to five by adding one solvent molecule. In the strong donor solvent DMSO, the Sn-OTeF(5) bond is broken and the (CH(3))(3)Sn(O=S(CH(3))(2))(2)(+) cation and the OTeF(5)(-) anion are formed. (CH(3))(3)SnOTeF(5) and (CH(3))(3)SnN(SO(2)CF(3))(2) react differently with water. While the Te-F bonds in the OTeF(5) group of (CH(3))(3)SnOTeF(5) undergo complete hydrolysis that results in the formation of [(CH(3))(3)Sn(H(2)O)(2)](2)SiF(6), (CH(3))(3)SnN(SO(2)CF(3))(2) forms the stable hydrate salt [(CH(3))(3)Sn(H(2)O)(2)][N(SO(2)CF(3))(2)]. This salt crystallizes in the monoclinic space group P2(1)/c (a = 7.3072(1) A, b =13.4649(2) A, c =16.821(2) A, beta = 98.705(1) degrees, V = 1636.00(3) A(3), Z = 4) and was also characterized by NMR and vibrational spectroscopy.     

Double NASICON-type cell: ordered Nd3+ distribution in Li0.2Nd0.8/3Zr2(PO4)3

The NASICON compound Li(0.2)Nd(0.8/3)Zr(2)(PO(4))(3), synthesized by a sol-gel process, has been structurally characterized by TEM and powder diffraction (neutron and X-ray). It crystallizes in the space group R3[combining macron] (No. 148): at room temperature, the Nd(3+) ions present an ordered distribution in the [Zr(2)(PO(4))(3)](-) network which leads to a doubling of the classical c parameter (a = 8.7160(3) A, c = 46.105(1) A). Above 600 degrees C, Nd(3+) diffusion occurs leading at 1000 degrees C to the loss of the supercell. This reversible cationic diffusion in a preserved 3D [Zr(2)(PO(4))(3)](-) network is followed through thermal X-ray diffraction. Ionic conductivity measurements have been undertaken by impedance spectroscopy, while some results concerning the sintering of the NASICON compound are given.     

Aqueous reactions of U(VI) at high chloride concentrations: syntheses and structures of new uranyl chloride polymers

The reactions of UO(3) with acidic aqueous chloride solutions resulted in the formation of two new polymeric U(VI) compounds. Single crystals of Cs(2)[(UO(2))(3)Cl(2)(IO(3))(OH)O(2)].2H(2)O (1) were formed under hydrothermal conditions with HIO(3) and CsCl, and Li(H(2)O)(2)[(UO(2))(2)Cl(3)(O)(H(2)O)] (2) was obtained from acidic LiCl solutions under ambient temperature and pressure. Both compounds contain pentagonal bipyramidal coordination of the uranyl dication, UO(2)(2+). The structure of 1 consists of infinite [(UO(2))(3)Cl(2)(IO(3))(mu(3)-OH)(mu(3)-O)(2)](2-) ribbons that run down the b axis that are formed from edge-sharing pentagonal bipyramidal [UO(6)Cl] and [UO(5)Cl(2)] units. The Cs(+) cations separate the chains from one another and form long ionic contacts with terminal oxygen atoms from iodate ligands, uranyl oxygen atoms, water molecules, and chloride anions. In 2, edge-sharing [UO(3)Cl(4)] and [UO(5)Cl(2)] units build up tetranuclear [(UO(2))(4)(mu-Cl)(6)(mu(3)-O)(2)(H(2)O)(2)](2-) anions that are bridged by chloride to form one-dimensional chains. These chains are connected in a complex network of hydrogen bonds and interactions of uranyl oxygen atoms with Li(+) cations. Crystal data: 1, orthorhombic, space group Pnma, a = 8.2762(4) A, b = 12.4809(6) A, c = 17.1297(8) A, Z = 4; 2, triclinic, space group P1, a = 8.110(1) A, b = 8.621(1) A, c = 8.740(1) A, Z = 2.     

Selenophosphate phase diagrams developed in conjunction with the synthesis of the new compounds K(2)La(P(2)Se(6))(1/2)(PSe(4)), K(3)La(PSe(4))(2), K(4)La(0.67)(PSe(4))(2), K(9-x)La(1+x/3)(PSe(4))(4) (x = 0.5), and KEuPSe(4)

Five new rare-earth metal polyselenophosphates have been synthesized by the reactive flux method and characterized by single-crystal X-ray diffraction: K(2)La(P(2)Se(6))(1/2)(PSe(4)) (I), K(3)La(PSe(4))(2) (II), K(4)La(0.67)(PSe(4))(2) (III), K(9-x)()La(1+)(x/3)(PSe(4))(4) (x = 0.5) (IV), and KEuPSe(4) (V). Compound I crystallizes in the monoclinic space group P2(1)/n with a = 9.4269(1) A, b = 7.2054(1) A, c = 21.0276(5) A, beta = 97.484(1) degrees, and Z = 4. Compound II crystallizes in the monoclinic space group P2(1)/c with a = 9.5782(2) A, b = 17.6623(4) A, c = 9.9869(3) A, beta = 90.120(1) degrees, and Z = 4. Compound III crystallizes in the orthorhombic space group Ibam with a = 19.0962(2) A, b = 9.1408(1) A, c = 10.2588(2) A, and Z = 4. Compound IV crystallizes in the orthorhombic space group Ccca with a = 18.2133(1) A, b = 38.0914(4) A, c = 10.2665(1) A, and Z = 8. Compound V crystallizes in the orthorhombic space group Pnma with a = 17.5156(11) A, b = 7.0126(5) A, c = 6.9015(4) A, and Z = 4. Optical band gap measurements show that compound V has an optical band gap of 1.88 eV. Solid-state Raman spectroscopy of compounds II-V shows the four normal vibrations expected for the (PSe(4))(3-) unit. The observation of compounds I-V in several reactions has allowed the creation of a quasi-quaternary phase diagram for potassium rare-earth-metal polyselenophosphates. This phase diagram can qualitatively be separated into three regions on the basis of the oxidation state of phosphorus in the crystalline products observed and takes the next step in designing solid-state compounds.     

Mg(XeF(2))(n)()](AsF(6))(2) (n = 4, 2): first compounds of magnesium with XeF(2)

The reaction between Mg(AsF(6))(2) and XeF(2) in anhydrous HF (aHF) at room temperature yields two compounds with XeF(2) bonded directly to the Mg(2+) cation: [Mg(XeF(2))(4)](AsF(6))(2); [Mg(XeF(2))(2)](AsF(6))(2). The 1:4 compound is obtained with excess XeF(2) while the 1:2 compound is prepared from stoichiometric amounts of Mg(AsF(6))(2) and XeF(2). [Mg(XeF(2))(4)](AsF(6))(2) crystallizes in an orthorhombic crystal system, space group P2(1)2(1)2(1), with a = 8.698(15) A, b = 14.517(15) A, c = 15.344(16) A, V = 1937(4) A(3), and Z = 4. The octahedral coordination sphere of Mg consists of one fluorine atom from each of the four XeF(2) molecules and two fluorine atoms from the two AsF(6) units. [Mg(XeF(2))(2)](AsF(6))(2) crystallizes in the orthorhombic crystal system, space group Pbam, with a = 8.9767(10) A, b = 15.1687(18) A, c = 5.3202(6) A, V = 724.42(14) A(3), and Z = 2. The octahedral coordination sphere consists of two fluorine atoms, one from each of the two XeF(2) molecules and four fluorine atoms from the four bridging AsF(6) units.