First structurally characterized actinide isocyanates

The synthesis and characterization of the neutral uranylisocyanate UO(2)(NCO)(2)(OP(NMe(2))(3))(2) [crystal data: monoclinic, P2(1)/c, a = 8.512(2) A, b = 10.931(2) A, c = 14.329(3) A, beta = 103.923(3) degrees , V = 1294.0(4) A(3), Z = 2] and isocyanato uranate (Et(4)N)(6)[(UO(2))(2)(NCO)(5)O](2) x 2CH(3)CN x H(2)O [crystal data: monoclinic, P2(1)/c, a = 17.2787(2) A, b = 15.560(1) A, c = 32.7619(4) A, beta = 94.0849(5) degrees , V = 8786.5(2) A(3), Z = 4] are reported. Not only are these compounds the first unambiguously characterized uranium isocyanates regardless of the oxidation state for uranium, but they are also the first structurally characterized actinide isocyanates. Both compounds show coordination of the OCN moiety through nitrogen to uranium and were characterized using IR and (1)H, (13)C, (14)N, and (31)P NMR spectroscopy and X-ray diffraction.     

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).     

Expanding the remarkable structural diversity of uranyl tellurites: hydrothermal preparation and structures of K[UO(2)Te(2)O(5)(OH)], Tl(3)[(UO(2))(2)[Te(2)O(5)(OH)](Te(2)O(6))].2H(2)O,beta-Tl(2)[UO(2)(TeO(3))(2)], and Sr(3)[UO(2)(TeO(3))(2)](TeO(3))(2)

The reactions of UO(2)(C(2)H(3)O(2))(2).2H(2)O with K(2)TeO(3).H(2)O, Na(2)TeO(3) and TlCl, or Na(2)TeO(3) and Sr(OH)(2).8H(2)O under mild hydrothermal conditions yield K[UO(2)Te(2)O(5)(OH)] (1), Tl(3)[(UO(2))(2)[Te(2)O(5)(OH)](Te(2)O(6))].2H(2)O (2) and beta-Tl(2)[UO(2)(TeO(3))(2)] (3), or Sr(3)[UO(2)(TeO(3))(2)](TeO(3))(2) (4), respectively. The structure of 1 consists of tetragonal bipyramidal U(VI) centers that are bound by terminal oxo groups and tellurite anions. These UO(6) units span between one-dimensional chains of corner-sharing, square pyramidal TeO(4) polyhedra to create two-dimensional layers. Alternating corner-shared oxygen atoms in the tellurium oxide chains are protonated to create short/long bonding patterns. The one-dimensional chains of corner-sharing TeO(4) units found in 1 are also present in 2. However, in 2 there are two distinct chains present, one where alternating corner-shared oxygen atoms are protonated, and one where the chains are unprotonated. The uranyl moieties in 2 are bound by five oxygen atoms from the tellurite chains to create seven-coordinate pentagonal bipyramidal U(VI). The structures of 3 and 4 both contain one-dimensional [UO(2)(TeO(3))(2)](2-) chains constructed from tetragonal bipyramidal U(VI) centers that are bridged by tellurite anions. The chains differ between 3 and 4 in that all of the pyramidal tellurite anions in 3 have the same orientation, whereas the tellurite anions in 4 have opposite orientations on each side of the chain. In 4, there are also additional isolated TeO(3)(2-) anions present. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 7.9993(5) A, b = 8.7416(6) A, c = 11.4413(8) A, Z = 4; 2, orthorhombic, space group Pbam, a = 10.0623(8) A, b = 23.024(2) A, c = 7.9389(6) A, Z = 4; 3, monoclinic, space group P2(1)/n, a = 5.4766(4) A, b = 8.2348(6) A, c = 20.849(3) A, beta = 92.329(1) degrees, Z = 4; 4, monoclinic, space group C2/c, a = 20.546(1) A, b = 5.6571(3) A, c = 13.0979(8) A, beta = 94.416(1) degrees, Z = 4.     

Linear Trinuclear Pt.Mo-Mo Complexes [Mo(2)PtX(2)(pyphos)(2)(O(2)CR)(2)](2) (X = Cl, Br, I; R = CH(3), C(CH(3))(3); pyphos = 6-(Diphenylphosphino)-2-pyridonate) with an Axial Interaction between the Quadruply Bonded Mo(2) Moiety and the Platinum Atom

An example of a direct axial interaction of a platinum(II) atom with a Mo(2) core through a uniquely designed tridentate ligand 6-(diphenylphosphino)-2-pyridonate (abbreviated as pyphos) is described. Treatment of PtX(2)(pyphosH)(2) (2a, X = Cl; 2b, X = Br; 2c, X = I) with a 1:1 mixture of Mo(2)(O(2)CCH(3))(4) and [Mo(2)(O(2)CCH(3))(2)(NCCH(3))(6)](2+) (3a) in dichloromethane afforded the linear trinuclear complexes [Mo(2)PtX(2)(pyphos)(2)(O(2)CCH(3))(2)](2) (4a, X = Cl; 4b, X = Br; 4c, X = I). The reaction of [Mo(2)(O(2)CCMe(3))(2)(NCCH(3))(4)](2+) (3b) with 2a-c in dichloromethane afforded the corresponding pivalato complexes [Mo(2)PtX(2)(pyphos)(2)(O(2)CCMe(3))(2)](2) (5a, X = Cl; 5b, X = Br; 5c, X = I), whose bonding nature is discussed on the basis of the data from Raman and electronic spectra as well as cyclic voltammograms. The linear trinuclear structures in 4b and 5a-c were confirmed by NMR studies and X-ray analyses: 4b, monoclinic, space group C2/c, a = 34.733(4) ?, b = 17.81(1) ?, c = 22.530(5) ?, beta = 124.444(8) degrees, V = 11498(5) ?(3), Z = 8, R = 0.060 for 8659 reflections with I > 3sigma(I) and 588 parameters; 5a, triclinic, space group P&onemacr;, a = 13.541(3) ?, b = 17.029(3) ?, c = 12.896(3) ?, alpha = 101.20(2) degrees, beta = 117.00(1) degrees, gamma = 85.47(2) degrees, V = 2599(1) ?(3), Z = 2, R = 0.050 for 8148 reflections with I > 3sigma(I) and 604 parameters; 5b, triclinic, space group P&onemacr;, a = 12.211(2) ?, b = 20.859(3) ?, c = 10.478(2) ?, alpha = 98.88(1) degrees, beta = 112.55(2) degrees, gamma = 84.56(1) degrees, V = 2433.3(8) ?(3), Z = 2, R = 0.042 for 8935 reflections with I > 3sigma(I) and 560 parameters; 5c, monoclinic, space group P2(1)/n, a = 13.359(4) ?, b = 19.686(3) ?, c = 20.392(4) ?, beta = 107.92(2) degrees, V = 5101(2) ?(3), Z = 4, R = 0.039 for 8432 reflections with I > 3sigma(I) and 560 parameters.     

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).     

U(VI) uranyl cation-cation interactions in framework germanates

The isomorphous compounds NH(4)[(UO(6))(2)(UO(2))(9)(GeO(4))(GeO(3)(OH))] (1), K[(UO(6))(2)(UO(2))(9)(GeO(4))(GeO(3)(OH))] (2), Li(3)O[(UO(6))(2)(UO(2))(9)(GeO(4))(GeO(3)(OH))] (3), and Ba[(UO(6))(2)(UO(2))(9)(GeO(4))(2)] (4) were synthesized by hydrothermal reaction at 220 °C. The structures were determined using single crystal X-ray diffraction and refined to R(1) = 0.0349 (1), 0.0232 (2), 0.0236 (3), 0.0267 (4). Each are trigonal, P(3)1c. 1: a = 10.2525(5), c = 17.3972(13), V = 1583.69(16) ?(3), Z = 2; 2: a = 10.226(4), c = 17.150(9), V = 1553.1(12) ?(3), Z = 2; 3: a = 10.2668(5), c = 17.0558(11), V = 1556.94(15) ?(3), Z = 2; 4: a = 10.2012(5), c = 17.1570(12), V = 1546.23(15) ?(3), Z = 2. There are three symmetrically independent U sites in each structure, two of which correspond to typical (UO(2))(2+) uranyl ions and the other of which is octahedrally coordinated by six O atoms. One of the uranyl ions donates a cation-cation interaction, and accepts a different cation-cation interaction. The linkages between the U-centered polyhedra result in a relatively dense three-dimensional framework. Ge and low-valence sites are located within cavities in the framework of U-polyhedra. Chemical, thermal, and spectroscopic characterizations are provided.     

Exploration of composition space in templated uranium sulfates

The phase stability of organically templated uranium sulfates in the [UO(2)(CH(3)CO(2))(2).2H(2)O/homopiperazine/H(2)SO(4)] and [UO(2)(CH(3)CO(2))(2).2H(2)O/N,N-dimethylethylenediamine/H(2)SO(4)] systems has been studied using composition space. Two new compounds were formed in each system; [N(2)C(5)H(14)](2)[UO(2)(SO(4))(3)] (USO-17) and [N(2)C(5)H(14)][UO(2)(H(2)O)(SO(4))(2)] (USO-18) contain homopiperazine, and [N(2)C(4)H(14)][UO(2)(SO(4))(2)] (USO-19) and [N(2)C(4)H(14)][(UO(2))(2)(H(2)O)(SO(4))(3)].H(2)O (USO-20) contain N,N-dimethylethylenediamine. The relative stability of the products from each system is dependent upon the reactant mole fractions in the initial reaction gel. Crystal data: USO-17, a = 14.4975(3) A, b = 11.9109(3) A, c = 13.0157(3) A, beta = 110.475(1) degrees, monoclinic, C2/c (No. 15), Z = 4; for USO-18, a = 7.6955(2) A, b = 11.7717(3) A, c = 14.7038(4) A, orthorhombic, P22(1)2(1) (No. 18), Z = 4; for USO-19, a = 9.3322(1) A, b = 9.7743(2) A, c = 13.8897(3) A, orthorhombic, P2(1)2(1)2(1) (No. 19), Z = 4; and for USO-20, a = 11.2460(2) A, b = 10.5387(2) A, c = 17.0432(3) A, beta = 92.9884(6) degrees, monoclinic, P2(1)/c (No. 14), Z = 4.     

Reactions of Elemental Indium and Indium(I) Bromide with Nickel-Bromine Bonds: Structure of (eta(5)-C(5)H(5))(Ph(3)P)Ni-InBr(2)(O=PPh(3))

The reactions of elemental indium and In(I)Br with the carbonyl-free organonickel complexes (eta(5)-C(5)H(5))(PR(3))Ni-Br (R = CH(3), C(6)H(5)) have been studied in some detail. Either redox reactions to yield the ionic products [(eta(5)-C(5)H(5))(PR(3))(2)Ni][InBr(4)] (2a,b) occurred or the Ni-In bound systems (eta(5)-C(5)H(5))(PPh(3))Ni-InBr(2)(OPPh(3)) (3a) and [(eta(5)-C(5)H(5))(PPh(3))Ni](2)InBr (4) were obtained in good yields. The new compounds were characterized by elemental analysis, NMR, and mass spectrometry. A short Ni-In bond of 244.65(9) pm was found for 3a. Single crystal data for (eta(5)-C(5)H(5))(PPh(3))Ni-InBr(2)(OPPh(3)).THF (3a): triclinic, P1 with a = 1124.9(3), b = 1353.2(4), c = 1476.4(4) pm, alpha = 94.74(2) degrees, beta = 101.78(2) degrees, gamma = 109.64(1) degrees, V = 2044(1) x 10(6) pm(3), Z = 2, R = 0.053 (R(w) = 0.063).     

X-ray Crystallographic Study of the Ruthenium Blue Complexes [Ru(2)Cl(3)(tacn)(2)](PF(6))(2).4H(2)O, [Ru(2)Br(3)(tacn)(2)](PF(6))(2).2H(2)O, and [Ru(2)I(3)(tacn)(2)](PF(6))(2): Steric Interactions and the Ru-Ru "Bond Length"

X-ray crystal structures are reported for the following complexes: [Ru(2)Cl(3)(tacn)(2)](PF(6))(2).4H(2)O (tacn = 1,4,7-triazacyclononane), monoclinic P2(1)/n, Z = 4, a = 14.418(8) ?, b = 11.577(3) ?, c = 18.471(1) ?, beta = 91.08(5) degrees, V = 3082 ?(3), R(R(w)) = 0.039 (0.043) using 4067 unique data with I > 2.5sigma(I) at 293 K; [Ru(2)Br(3)(tacn)(2)](PF(6))(2).2H(2)O, monoclinic P2(1)/a, Z = 4, a = 13.638(4) ?, b = 12.283(4) ?, c = 18.679(6) ?, beta = 109.19(2) degrees, V = 3069.5 ?(3), R(R(w)) = 0.052 (0.054) using 3668 unique data with I > 2.5sigma(I) at 293 K; [Ru(2)I(3)(tacn)(2)](PF(6))(2), cubic P2(1)/3, Z = 3, a = 14.03(4) ?, beta = 90.0 degrees, V = 2763.1(1) ?(3), R (R(w)) = 0.022 (0.025) using 896 unique data with I > 2.5sigma(I) at 293 K. All of the cations have cofacial bioctahedral geometries, although [Ru(2)Cl(3)(tacn)(2)](PF(6))(2).4H(2)O, [Ru(2)Br(3)(tacn)(2)](PF(6))(2).2H(2)O, and [Ru(2)I(3)(tacn)(2)](PF(6))(2) are not isomorphous. Average bond lengths and angles for the cofacial bioctahedral cores, [N(3)Ru(&mgr;-X)(3)RuN(3)](2+), are compared to those for the analogous ammine complexes [Ru(2)Cl(3)(NH(3))(6)](BPh(4))(2) and [Ru(2)Br(3)(NH(3))(6)](ZnBr(4)). The Ru-Ru distances in the tacn complexes are longer than those in the equivalent ammine complexes, probably as a result of steric interactions.     

Thiophosphate phase diagrams developed in conjunction with the synthesis of the new compounds KLaP(2)S(6), K(2)La(P(2)S(6))(1/2)(PS(4)), K(3)La(PS(4))(2), K(4)La(0.67)(PS(4))(2), K(9-)(x)La(1+x/3)(Ps(4))(4) (x = 0.5), K(4)Eu(PS(4))(2), and KEuPS(4)

An alkali-metal sulfur reactive flux has been used to synthesize a series of quaternary rare-earth metal compounds. These include KLaP(2)S(6) (I), K(2)La(P(2)S(6))(1/2)(PS(4)) (II), K(3)La(PS(4))(2) (III), K(4)La(0.67)(PS(4))(2) (IV), K(9-x)La(1+x/3)(PS(4))(4) (x = 0.5) (V), K(4)Eu(PS(4))(2) (VI), and KEuPS(4) (VII). Compound I crystallizes in the monoclinic space group P2(1)/c with the cell parameters a = 11.963(12) A, b = 7.525(10) A, c = 11.389(14) A, beta = 109.88(4) degrees, and Z = 4. Compound II crystallizes in the monoclinic space group P2(1)/n with a = 9.066(6) A, b = 6.793(3) A, c = 20.112(7) A, beta = 97.54(3) degrees, and Z = 4. Compound III crystallizes in the monoclinic space group P2(1)/c with a= 9.141(2) A, b = 17.056(4) A, c = 9.470(2) A, beta = 90.29(2) degrees, and Z = 4. Compound IV crystallizes in the orthorhombic space group Ibam with a = 18.202(2) A, b = 8.7596(7) A, c = 9.7699(8) A, and Z = 4. Compound V crystallizes in the orthorhombic space group Ccca with a = 17.529(9) A, b = 36.43(3) A, c = 9.782(4) A, and Z = 8. Compound VI crystallizes in the orthorhombic space group Ibam with a = 18.29(5) A, b = 8.81(2) A, c= 9.741(10) A, and Z = 4. Compound VII crystallizes in the orthorhombic space group Pnma with a = 16.782(2) A, b = 6.6141(6) A, c = 6.5142(6) A, and Z = 4. The sulfur compounds are in most cases isostructural to their selenium counterparts. By controlling experimental conditions, these structures can be placed in quasi-quaternary phase diagrams, which show the reaction conditions necessary to obtain a particular thiophosphate anionic unit in the crystalline product. These structures have been characterized by Raman and IR spectroscopy and UV-vis diffuse reflectance optical band gap analysis.     

Synthesis and structure of Ag(6)[(UO(2))(3)O(MoO(4))(5)]: a novel sheet of triuranyl clusters and MoO(4) tetrahedra

The new uranyl molybdate Ag(6)[(UO(2))(3)O(MoO(4))(5)] (1) with an unprecedented uranyl molybdate sheet has been synthesized at 650 degrees C. The structure (monoclinic, C2/c, a = 16.4508(14) A, b = 11.3236(14) A, c = 12.4718(13) A, beta = 100.014(4)(o), V = 2337.4(4) A(3), Z = 4) contains [(UO(2))(3)O(MoO(4))(5)] sheets composed of triuranyl [(UO(2))(3)O] clusters that are connected by MoO(4) tetrahedra. The topology of the uranyl molybdate sheet in 1 represents a major departure from sheets observed in other uranyl compounds. Of the approximately 120 known inorganic uranyl compounds containing sheets of polyhedra, 1 is the only structure that contains trimers of uranyl pentagonal bipyramids that are connected only by the sharing of vertexes with other polyhedra. The sheets are parallel to (001) and are linked by Ag cations.     

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.     

Expanding the crystal chemistry of uranyl peroxides: synthesis and structures of di- and triperoxodioxouranium(VI) complexes

Four compounds containing tri- and diperoxodioxouranium(VI) complexes have been synthesized under ambient conditions and structurally characterized. The crystal structures of Na4(UO2)(O2)3(H2O)12 (monoclinic, P21/c, a=6.7883(6) A, b=16.001(2) A, c=16.562(2) A, beta=91.917(2) degrees, V=1797.9(3) A3, Z=4) and Ca2(UO2)(O2)3(H2O)9 (orthorhombic, Pbcn, a=9.576(3) A, b=12.172(3) A, c=12.314(2) A, V=1435.4(6) A3, Z=4) contain clusters of triperoxodioxouranium(VI). These clusters are bonded through a network of H bonding to H2O groups and in the Ca compound by bonds to Ca2+ cations. In the crystal structure of Na2Rb4(UO2)2(O2)5(H2O)14 (orthorhombic, Pbcm, a=6.808(2) A, b=16.888(6) A, c=23.286(8) A, V=2677.5(16) A3, Z=4), triperoxodioxouranium(VI) polyhedra share a peroxide edge, forming dimers of polyhedra of composition (UO2)2(O2)5(6-). Adjacent dimers are linked through bonding to Rb+ cations and by H bonds to H2O groups. The crystal structure of K6[(UO2)(O2)2(OH)]2(H2O)7 (orthorhombic, Pcca, a=15.078(8) A, b=6.669(4) A, c=23.526(13) A, V=2366(2) A3, Z=4) contains diperoxodioxouranium(VI) polyhedra that include two OH groups. These polyhedra share an OH-OH edge, forming dimers of composition (UO2)2(O2)4(OH)2(6-). The dimers are linked by bonds to K+ cations and by H bonding to H2O groups.     

Rhenium(I) carbonyl complexes of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPT). Rhenium(I)-promoted methoxylation of the triazine ring carbon atom in dinuclear rhenium complexes

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (TPT) bridged dinuclear rhenium(I) tricarbonyl halide complexes with the composition (mu-TPT)[ReX(CO)(3)](2) (3, X = Cl; 4, X = Br) can be made either by one-pot reaction of TPT with 2 equiv of [ReX(CO)(5)] (X = Cl and Br) in chloroform or by reacting mononuclear [ReX(CO)(3)(TPT)] (2) (1, X = Cl; 2, X = Br) with an excess amount of [ReX(CO)(5)]. Crystal data are as follows. 1: monoclinic, P2(1)/c, a = 11.751(1) A, b = 11.376(1) A, c = 15.562(2) A, beta = 103.584(2) degrees, V = 2022.0(4) A(3), Z = 4. 2: monoclinic, P2(1)/c, a = 11.896(1) A, b = 11.396(1) A, c = 15.655(1) A, beta = 104.474(2) degrees, V = 2054.9(3) A(3), Z = 4. 3: triclinic, P1, a = 11.541(2) A, b = 12.119(2) A, c = 13.199(2) A, alpha = 80.377(2) degrees, beta = 76.204(3) degrees, gamma = 66.826(2) degrees, V = 1642.5(4) A(3), Z = 2. Crystals of 4 crystallized from acetone: triclinic, P1, a = 11.586(5) A, b = 12.144(5) A, c = 13.364(6) A, alpha = 80.599(7) degrees, beta = 76.271(8) degrees, gamma = 67.158(8) degrees, V = 1678.0(12) A(3), Z = 2. Crystals of 4' are obtained from CH(2)Cl(2)-pentane solution: monoclinic, C2/c, a = 17.555(4) A, b = 15.277(3) A, c = 13.093(3) A, beta = 111.179(3) degrees, V = 3274.0(12) A(3), Z = 4. By contrast, similar reactions in the presence of methanol yielded complexes with the composition [mu-C(3)N(3)(OMe)(py)(2)(pyH)][ReX(CO)(3)](2) (5, X = Cl; 6, X = Br). Crystal data for 5: monoclinic, C2/c, a = 26.952(2) A, b = 16.602(1) A, c = 14.641(1) A, beta = 116.147(1) degrees, V = 5880.5(8) A(3), Z = 8. 6: monoclinic, C2/c, a = 27.513(3) A, b = 16.740(2) A, c = 14.837(2) A, beta = 116.925(2) degrees, V = 6092.8(10) A(3), Z = 8. An unusual metal-induced methoxylation at the carbon atom of the triazine ring of the bridging TPT ligand was observed. The nucleophilic attack of MeO(-) on C(3) results in a tetrahedral geometry around the carbon atom. Concomitantly, the uncoordinated pyridyl ring is protonated and rotated into a perpendicular orientation relative to the central C(3)N(3) ring. Reaction of TPT with [NEt(4)](2)[ReBr(3)(CO)(3)] in benzene-methanol resulted in an unexpected dinuclear complex 7, with formulation [mu-C(3)N(3)(OMe)(py)(3)][Re(CO)(3)][ReBr(CO)(3)]. The methoxylated TPT ligand functions simultaneously as a tridentate and bidentate ligand with two fac-Re(CO)(3)(+) cores. Crystal data for 7: monoclinic, P2(1)/n, a = 12.114(1) A, b = 14.878(1) A, c = 15.807(1) A, beta = 104.601(1) degrees, V = 2756.9(3) A(3), Z = 4.     

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.     

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.     

Octahedral coordination of halide ions (I-, Br-, Cl-) sandwich bonded with tridentate mercuracarborand-3 receptors

The "anti-crown" B-hexamethyl 9-mercuracarborand-3 (1) was shown to complex halide ions (I-, Br-, Cl-) in an eta(3)-sandwich fashion. Symmetry-allowed interactions of the filled halide ion p-orbitals and the corresponding empty mercury p-orbitals result in three equivalent p(Hg)-p(halide)-p(Hg) three-center two-electron bonds and a sandwich structure. The molecular structures of [Li.(H(2)O)(4)][1(2).I].2CH(3)CN, MePPh(3)[1(2).Br].((CH(3))(2)CO)(2).(H(2)O)(2), and PPN[1(2).Cl] were determined by single-crystal X-ray diffraction studies. Compound [Li.(H(2)O)(4)][1(2).I].2CH(3)CN crystallized in the triclinic space group P-1, a = 13.312(8) A, b = 13.983(9) A, c = 13.996(9) A, alpha = 61.16(2) degrees, beta = 82.34(2) degrees, gamma = 86.58(2) degrees, V = 4365(2) A(3), Z = 1, R = 0.063, and R(w) = 0.171. Compound MePPh(3)[1(2).Br].((CH(3))(2)CO)(2).(H(2)O)(2) crystallized in the monoclinic space group C2/c, a = 24.671(8) A, b = 17.576(6) A, c = 26.079(8) A, beta = 106.424(6) degrees, V = 10847(6) A(3), Z = 8, R = 0.0607, and R(w) = 0.1506. Compound PPN[1(2).Cl] crystallized in the monoclinic space group C2/m, a = 37.27(2) A, b = 29.25(1) A, c = 10.990(4) A, beta = 100.659(7) degrees, V = 11774(8) A(3), Z = 4, R = 0.0911, and R(w) = 0.2369.     

Unique hydrogen bonding correlating with a reduced band gap and phase transition in the hybrid perovskites (HO(CH2)2NH3)2PbX4 (X = I, Br)

The first hybrid perovskites incorporating alcohol-based bifunctional ammonium cations, (HO(CH(2))(2)NH(3))(2)PbX(4) (X = I, Br), have been prepared and characterized. (HO(CH(2))(2)NH(3))(2)PbI(4) adopts a monoclinic cell, a = 8.935(1) A, b= 9.056(2) A, c = 10.214(3) A, beta = 100.26(1) degrees , V = 813.3(3) A(3), P2(1)/a, and Z = 2, and (HO(CH(2))(2)NH(3))(2)PbBr(4) is orthorhombic, a = 8.4625(6) A, b = 8.647(1) A, c = 19.918(2) A, V = 1457.5(2) A(3), Pbcn, and Z = 4. In the layered structures, a unique hydrogen-bond network connects adjacent perovskite layers, owing to OH....X, NH(3)(+)....X, and intermolecular NH(3)(+)...OH interactions. Its impact on the bonding features of the inorganic framework and on the quite short interlayer distance, in the case of (HO(CH(2))(2)NH(3))(2)PbI(4), is shown. As a result, a significant red shift of the exciton peaks (lambda = 536 nm (X = I), lambda = 417 nm (X = Br)), compared to other PbX(4)(2)(-)-based perovskite hybrids, is observed, revealing a reduced band gap. A reversible structural transition occurs at T = 96 degrees C (X = I) and T = 125 degrees C (X = Br). An orthorhombic cell of the high-temperature phase of (HO(CH(2))(2)NH(3))(2)PbI(4) with a(HT) = 18.567(6) A, b(HT) = 13.833(6) A, c(HT) = 6.437(2) A, and V = 1653 A(3) is proposed from powder X-ray diffraction. A change in the hydrogen bonding occurs, with molecules standing up in the interlayer space and OH parts probably interacting together, leading to a more conventional situation for ammonium groups and a more distorted perovskite layer. This is in accordance with the blue shift of the exciton peak to lambda = 505 nm (X = I) or to lambda = 374 nm (X = Br) during the phase transition.     

Pyridylazole chelation of oxorhenium(V) and imidorhenium(V). Rates and trends of oxygen atom transfer from Re(V)O to tertiary phosphines

The concerned azoles are 2-(2-pyridyl)benzoxazole (pbo) and 2-(2-pyridyl)benzthiazole (pbt). These react with ReOCl(3)(PPh(3))(2) in benzene, affording Re(V)OCl(3)(pbo) and Re(V)OCl(3)(pbt), which undergo facile oxygen atom transfer to PPh(2)R (R = Ph, Me) in dichloromethane solution, furnishing Re(III)(OPPh(2)R)Cl(3)(pbo) and Re(III)(OPPh(2)R)Cl(3)(pbt). The oxo species react with aniline in toluene solution, yielding the imido complexes Re(V)(NPh)Cl(3)(pbo) and Re(V)(NPh)Cl(3)(pbt). The X-ray structures of pbt, ReOCl(3)(pbt), Re(OPPh(3))Cl(3)(pbt), and Re(NPh)Cl(3)(pbo) are reported. The lattice of pbt consists of stacked dimers. In all the complexes the azole ligand is N,N-chelated and the ReCl(3) moiety is meridionally disposed. In ReOCl(3)(pbt) the metal-oxo bond length is 1.607(9) A. The second-order rates and the associated activation parameters of the oxygen atom transfer reactions of the Re(V)O chelates with PPh(2)R are reported. The large and negative entropy of activation (approximately -24 eu) is consistent with an associative pathway involving nucleophilic phosphine attack. The rate increases with phosphine basicity (PPh(2)Me > PPh(3)) and azole heteroatom electronegativity (O(pbo) > S(pbt)). Logarithmic rate constants for ReOCl(3)(pbo), ReOCl(3)(pbt), and ReOCl(3)(pal) are found to correlate linearly with Re(VI)O/Re(V)O reduction potentials (pal is pyridine-2-(N-p-tolyl)aldimine). The relatively low rate constant of ReOCl(3)(pbt) compared to that of ReOCl(3)(pal) is consistent with the observed shortness of the metal-oxo bond in the former. Crystal data are as follows: (pbt) empirical formula C(12)H(8)N(2)S, crystal system orthorhombic, space group Pca2(1), a = 13.762(9) A, b = 12.952(8) A, c = 11.077(4) A, V = 1974(2) A(3), Z = 8; (ReOCl(3)(pbt)) empirical formula C(12)H(8)Cl(3)N(2)OSRe, crystal system monoclinic, space group P2(1)/c, a = 11.174(7) A, b = 16.403(10) A, c = 7.751(2) A, beta = 99.35(4) degrees, V = 1401.8(13) A(3), Z = 4; (Re(NPh)Cl(3)(pbo)) empirical formula C(18)H(13)Cl(3)N(3)ORe, crystal system monoclinic, space group P2(1)/c, a = 9.566(6) A, b = 16.082(8) A, c = 11.841(5) A, beta = 94.03(4) degrees, V = 1817(2) A(3), Z = 4.     

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.