Synthesis and characterization of the silver maleonitrilediselenolates and silver maleonitriledithiolates [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4], [Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4].0.33MeCN, [NBu4]4[Ag4(S2C2(CN)2)4], [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2].2MeCN, and [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2

Reaction of AgBF(4), KNH(2), K(2)Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)](4)[Ag(4)(Se(2)C(2)(CN)(2))(4)] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)](+) units and a tetrahedral Ag(4) anionic core coordinated in mu(1)-Se, mu(2)-Se fashion by each of four mns ligands (mns = maleonitrilediselenolate, [Se(2)C(2)(CN)(2)](2)(-)). Reaction of AgNO(3), Na(2)(mnt) (mnt = maleonitriledithiolate, [S(2)C(2)(CN)(2)](2)(-)), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)](4)[Ag(4)(mnt)(4)].0.33MeCN (2). The Ag(4) anion of 2 is analogous to that in 1. Reaction of AgNO(3), Na(2)(mnt), and [NBu(4)]Br in acetonitrile yields [NBu(4)](4)[Ag(4)(mnt)(4)] (3). The anion of 3 also comprises an Ag(4) core coordinated by four mnt ligands, but the Ag(4) core is diamond-shaped rather than tetrahedral. Reaction of [K([2.2.2]-cryptand)](3)[Ag(mns)(Se(6))] with KNH(2) and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)](3)[Ag(mns)(2)].2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral arrangement. Reaction of AgNO(3), 2 equiv of Na(2)(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)](3)[Ag(mnt)(2)] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n, Z = 2, a = 18.362(2) A, b = 16.500(1) A, c = 19.673(2) A, beta = 94.67(1) degrees, V = 5941(1) A(3); 2, P4, Z = 4, a= 27.039(4) A, c = 15.358(3) A, V = 11229(3) A(3); 3, P2(1)/c, Z = 6, a = 15.689(3) A, b = 51.924(11) A, c = 17.393(4) A, beta = 93.51(1) degrees, V = 14142(5) A(3); 4, P2(1)/c, Z = 4, a = 13.997(1) A, b = 21.866(2) A, c = 28.281(2) A, beta = 97.72(1) degrees, V = 8578(1) A(3); 5, P2/n, Z = 2, a = 11.547(2) A, b = 11.766(2) A, c = 27.774(6) A, beta = 91.85(3) degrees, V = 3772(1) A(3).     

Cs3AgAs4Se8 and CsAgAs2Se4: selenoarsenates with infinite 1 infinity[AsSe2]- chains in different Ag+ coordination environments

Two quaternary silver selenoarsenates Cs3AgAs4Se8 (I) and CsAgAs2Se4 (II) have been discovered by methanothermal reaction of Li3AsSe3 with AgBF4 in the presence of the respective alkali metal sources Cs2CO3 and CsCl. Orange crystals of Cs3AgAs4Se8 (I) were formed after reaction at 120 degrees C for 72 h, whereas red CsAgAs2Se4 (II) was obtained under slightly different conditions at 140 degrees C for 70 h. Both compounds possess novel two-dimensional (2D) polyanions consisting of infinite 1 infinity[AsSe2]- chains that are interconnected by Ag+ ions in different coordination patterns. In I, a double layer of 1 infinity[AsSe2]- chains is bridged by distorted trigonal planar coordinated Ag+ atoms to form a 2 infinity[AgAs4Se8]3- layer with a thickness of about 11.3 A. The nonbonding Ag...Ag distances are about 4.220 A, and large cavities within the layers accommodate for three of the four crystallographic Cs+ cations. The double amount of Ag+ atoms per AsSe2 chain unit in II leads to simple layers 2 infinity[AgAs2Se4]- [=[Ag2As4Se8]2-] in which the Ag+ atoms are arranged in rows between the 1 infinity[AsSe2]- chains, with alternating Ag...Ag distances of 3.053(3) and 3.488(3) A. Hereby the 1 infinity[AsSe2]- polyanions show a disorder within the central (-As-Seb)- chain (b = bridging), while the positions of the terminal Se atoms (Set) remain unaffected. The thermal, optical, and spectroscopic properties of the compounds are reported. Both I and II melt with decomposition and are wide band gap semiconductors with values of 2.07 and 1.79 eV, respectively. Raman spectroscopic data show typical band patterns expected for infinite [AsSe2]- chains. Crystal Data: Cs3AgAs4Se8 (I), monoclinic, C2/c, a = 25.212(2) A, b = 8.0748(7) A, c = 22.803(2) A, beta = 116.272(2) degrees, Z = 8; CsAgAs2Se4 (II), monoclinic, P2(1)/n, a = 10.9211(1) A, b = 6.5188(2) A, c = 13.7553(3) A, beta = 108.956(1) degrees, Z = 4.     

Syntheses and structural, physical, and theoretical studies of the novel isostructural Mo9 cluster compounds Ag(2.6)CsMo9Se11, Ag(4.1)ClMo9Se11, and h-Mo9Se11 with tunnel structures

The new isostructural compounds Ag(2.6)CsMo9Se11 (1) and Ag(4.1)ClMo9Se11 (2) were prepared by solid-state reaction in evacuated sealed silica tubes at 1200 degrees C and 860 degrees C, respectively. By topotactic reduction-oxidation reaction of Ag(4.1)ClMo9Se11 with I2, we also obtained the metastable compound h-Mo9Se11 (3). The three compounds crystallize in the hexagonal space group P6(3)/m, Z = 2, (1) a = 10.0472(2) A, c = 11.9548(2), (2) a = 10.0321(2) A, c = 11.8734(2) A, and (3) a = 9.4204(2) A, c = 12.1226(2) A. Their crystal structures were determined from single-crystal X-ray diffraction data and consist of interconnected Mo9Se11 units forming an original and unprecedented three-dimensional framework in which large tunnels are occupied randomly by a part of the Ag+ and the Cl- ions in 2 and the Cs+ ions in 1, the remaining Ag+ in 1 being localized in mirror planes around the 3-fold axis. First-principle calculations allow the understanding of the variation of the atomic distances. Electrical resistivity measurements carried out on single crystals of Ag(2.6)CsMo9Se11 and Ag(4.1)ClMo9Se11 in which the number of electrons per Mo9 cluster is different indicate that the former is semiconducting whereas the latter is semimetallic.     

Selenium-centered, undecanuclear silver cages surrounded by iodo and dialkyldiselenophosphato ligands. Syntheses, structures, and photophysical properties

Three clusters [Ag11(mu9-Se)(mu3-I)3{Se2P(OR)2}6] (R = Et, 1; iPr, 2; 2Bu, 3) were isolated from the reaction of [Ag(CH3CN)4](PF6), NH4[Se2P(OR)2], and Bu4NI in a molar ratio of 4:3:1 in CH2Cl2 in 47-55% yield. Compounds 1 and 2 can also be synthesized with high yield from the reaction of Ag10(Se)[Se2P(OR)2]8 with 8 equiv of Bu4NI. In the positive fast atom bombardment mass spectra of 1-3, two major peaks that correspond to the intact molecule with the loss of an iodide ion, [Ag11(mu9-Se)(mu3-I)(2){Se2P(OR)2}6]+, and a diselenophosphate ligand, [Ag11(mu9-Se)(mu3-I)3{Se2P(OR)2}5]+, were identified. Single-crystal X-ray analyses of 2 and 3 reveal an Ag11Se core stabilized by three iodide anions and six diselenophosphato ligands in a tetrametallic tetraconnective (mu2,mu2) coordination mode. The central core adopts the geometry of a 3,3,4,4,4-pentacapped trigonal prism with a selenium atom in the center. In addition, weak intermolecular Se...I interactions exist in 2 and form a one-dimensional polymeric chain structure. Furthermore, all compounds exhibit orange-red luminescence in both the solid state and solution.     

Structures and physical properties of new semiconducting polyselenides Ba2CudeltaAg4-deltaSe5 with unprecedented linear Se(3)4- units

The title compounds were prepared from the elements in evacuated silica tubes at 650 degrees C, followed by slow cooling. Ba2Ag4Se5 forms a new structure type, space group C2/m, with a=16.189(2) A, b=4.5528(6) A, c=9.2500(1) A, beta=124.572(3) degrees, and V=561.4(1) A3 (Z=2). A maximum of 44% of the Ag atoms may be replaced with Cu atoms without changing the structure type. The crystal structure is composed of Ag4Se(5)4- layers, interconnected via the Ba2+ cations. The Ag atoms show irregular [3+1] coordination by the Se atoms, and the Ba atoms are located in capped square antiprisms formed by Se atoms. Most intriguing is the unprecedented occurrence of linear Se(3)4- units. According to the formulation (Ba2+)2(Ag+)4Se(3)4-(Se2-)2, this selenide is electron-precise with eight positive charges equalizing the eight negative charges. Electronic structure calculations indicated the presence of a band gap, as was experimentally confirmed: the electrical conductivity measurement revealed a gap of 0.6 eV for Ba2CuAg3Se5.     

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.     

Synthesis and Re—refinement of Cu3PSe4

1 INTRODUCTION The chemistry of mixed 15/16 main group compounds has attracted great attentions over the last years[1]. The metal chalcogenophosphides synthesized by solid state reactions[2] are the potential candidates for a wide range of applications such as semiconducting properties, two-dimensional magnetic behavior, anisotropy of conductivity and charge density waves. Some of these compounds are of lamellar structure, which are good materials for the investigation of intercalatio…     

Pseudo-polyrotaxane and beta-sheet layer-based three-dimensional coordination polymers constructed with silver salts and flexible pyridyl-type ligands

A fascinating 3D pseudo-polyrotaxane architecture with 1D polymeric [Ag(bpp)](n) chains penetrating 2D (6,3) [Ag(2)(bpp)(2)(ox)](n) sheets and a 3D coordination network constructed with 2D infinite [Ag(ppa)](n) beta-sheetlike layers pillared by ox ligands (bpp = 1,3-bis(4-pyridyl)propane; ppa = N-(4-pyridinylmethyl)-4-pyridinecarboxamide; ox = oxalate) have been prepared by utilizing flexible pyridyl-type ligands and have been crystallographically characterized. Crystal data for 1: monoclinic, space group C2/c, a = 7.619(2) A, b = 19.781(4) A, c = 26.799(5) A, beta = 94.720(10) degrees, U = 4025.2(15) A(3), and Z = 4. Crystal data for 2: monoclinic, space group C2/c, a = 28.947(8) A, b = 8.617(3) A, c = 16.307(6) A, beta =121.07(1) degrees, U = 3484(2) A(3), and Z = 4.     

Self-Assembly of Ribbons and Frameworks Containing Large Channels Based upon Methylene-Bridged Dithio-, Diseleno-, and Ditelluroethers

Homoleptic copper(I) and silver(I) complexes [M(n)(L-L)(2)(n)()](BF(4))(n)() (M = Cu or Ag; L-L = MeECH(2)EMe; E = S, Se or Te) have been prepared and characterized by analysis, FAB mass spectrometry, and IR and multinuclear NMR spectroscopy ((1)H, (77)Se, (125)Te, (63)Cu and (109)Ag). The single-crystal X-ray structures of [Cu(n)()(MeSeCH(2)SeMe)(2)(n)()](PF(6))(n)() (orthorhombic, P2(1)2(1)2(1), a = 10.879(7) ?, b = 16.073(7) ?, c = 9.19(1) ?, Z = 4) and [Ag(n)()(MeSeCH(2)SeMe)(2)(n)()](BF(4))(n)() (monoclinic, P2(1)/c, a = 14.546(9) ?, b = 14.65(1) ?, c = 30.203(9) ?, Z = 4) reveal extended three-dimensional cationic frameworks in the solid state which contain large cylindrical or rectangular channels accommodating the PF(6)(-) or BF(4)(-) counterions. In contrast, a single-crystal X-ray structure of [Cu(n)()(MeSCH(2)SMe)(2)(n)()](PF(6))(n)().nMeNO(2) (orthorhombic, Pbcn, a = 15.506(3) ?, b = 8.934(2) ?, c = 25.859(3) ?, Z = 8) shows tetrahedral Cu(I) ions coordinated to bridging dithioethers forming an cationic ribbon-like arrangement of 8-membered rings. Adjacent rings are linked by the Cu atoms. Variable temperature NMR studies have been used to probe various exchange processes occurring in solution in these systems.     

Self-assembly of a series of extended architectures based on polyoxometalate clusters and silver coordination complexes

Three unusual compounds based on polyoxometalate building blocks, [(H2O)5Na2(C6NO2H4)(C6NO2H5)3Ag2][Ag2IMo6O24(H2O)4] x 6.25H2O (1), [(H2O)4Na2(C6NO2H5)6Ag3][IMo6O24] x 6H2O (2), and (C6NO2H6)2[(C6NO2H5)2Ag][Cr(OH)6Mo6O18] x 4H2O (3), have been synthesized and characterized by elemental analysis; IR, XPS, and ESR spectroscopy; TG analysis; and single-crystal X-ray diffraction. Compound 1 is constructed from the cationic two-dimensional (2D) coordination polymer sheets which are constituted of [(H2O)5Na2(C6NO2H4)(C6NO2H5)3Ag2]3+ and anionic [Ag2IMo6O24(H2O)4]3- chains as pillars, forming a three-dimensional (3D) supramolecular framework via weak Ag-O interactions. Compound 2 is composed of the well-defined [IMo6O24]5- building blocks, which are linked through trinuclear Ag-pyridine-3-carboxylic acid, [(C6NO2H5)6Ag3]3+, fragments into a one-dimensional (1D) hybrid chain; adjacent chains are further connected by sodium cations to yield a novel 2D network. Compound 3 has a 1D chainlike structure constructed from [Cr(OH)6Mo6O18]3- building blocks and Ag-pyridine-4-carboxylic acid coordination units. The crystal data for these compounds are the following: 1, triclinic, P1, a = 13.280(3) A, b = 13.641(3) A, c = 16.356(3) A, alpha = 89.68(3) degrees, beta = 88.31(3) degrees, gamma = 75.87(3) degrees, Z = 2; 2, triclinic, P1, a = 11.978(2) A, b = 12.008(2) A, c = 13.607(3) A, alpha = 116.14(3) degrees, beta = 108.85(3) degrees, gamma = 93.86(3) degrees, Z = 1; 3, triclinic, P1, a = 10.458(2) A, b = 10.644(2) A, c = 12.295(3) A, alpha = 97.40(3) degrees, beta = 112.38(3) degrees, gamma = 113.59(3) degrees, Z = 1.     

Synthesis of a family of solids through the building-block approach: a case study with Ag(+) substitution in the ternary Na-Ge-Se system

A new family of Ag-substituted pseudoquaternary alkali-seleno-germanates has been synthesized by two solid-state routes: the conventional flux method and metathesis. This family includes a series of semiconductors with varying amounts of Ag+ substituted for Na+ in Na8Ge4Se10 to form AgxNa(8-x)Ge4Se10, [x = 0.31 (I), 0.67 (II), 0.77 (III), 0.87 (IV), 1.05 (V), 1.09 (VI)] and another phase with a different composition AgxNa(6-x)Ge2Se7 (x = 1.76), VII, related to Na6Ge2Se7. In I-VI, Ge4Se10(8-) constitutes a 6-membered chairlike unit with a Ge-Ge bond, while in VII, a corner-shared dimer of GeSe4 tetrahedra (Ge2Se76-) acts as the building unit. The single-crystal structure analysis indicates that there is a phase transition from P to C2/c, in changing from pure Na8Ge4Se10 to AgxNa(8-x)Ge4 Se10 (I-VI), while there is no phase transition between pure Na6Ge2Se7 and AgxNa(6-x)Ge2Se7 (x = 1.76). The structures of I-VI may be described in terms of layers of cubic close-packed Se2- anions. In between the Se layers, octahedral holes fully occupied by Na+ and mixed Ag+/Na+ cations alternate with layers formed of octahedral holes fully occupied by Na+ and Ge26+ cations. Two adjacent Ge26+ cations form a chairlike Ge4Se10(8-) anion in which Ge-Ge bonds are oriented almost parallel to the Se layers. In contrast, VII does not have close-packed anions. Corner-shared GeSe4 tetrahedra (Ge2Se7(6-) dimer) and AgSe4 tetrahedra form layers that are cross-linked by Na/AgSe4 tetrahedra to form a 3-dimensional (3-D) structure. An optical property investigation indicates a red shift in the band gap of AgxNa(8-x)Ge4Se10 (x = 0.67)(II) as compared to that of pure Na8Ge4Se10. Raman data also indicate a red shift of the Ge-Se stretching mode in the Ag+-substituted phase II (x = 0.67) compared to that of Na8Ge4Se10.     

Luminescent homo- and heteropolynuclear platinum(II) chalcogenido aggregates based on [Pt2E2(P empty set N)4] units (E=S,Se)

A series of homodinuclear platinum(II) complexes containing bridging chalcogenido ligands, [Pt(2)(mu-E)(2)(P empty set N)(4)] (P empty set N=dppy, E=S (1), Se (2); P empty set N=tBu-dppy, E=S (3)) (dppy=2-(diphenylphosphino)pyridine, tBu-dppy=4-tert-butyl-2-(diphenylphosphino)pyridine) have been synthesized and characterized. The nucleophilicity of the [Pt(2)E(2)] unit towards a number of d(10) metal ions and complexes has been demonstrated through the successful isolation of a number of novel heteropolynuclear platinum(II)-copper(I), -silver(I), and -gold(I) complexes: [[Pt(2)(mu(3)-E)(2)(dppy)(4)](2)Ag(3)](PF(6))(3) (E=S (4); Se (5)) and [Pt(2)(dppy)(4)(mu(3)-E)(2)M(2)(dppm)]X(2) (E=S, M=Ag, X=BF(4) (6); E=S, M=Cu, X=PF(6) (7); E=S, M=Au, X=PF(6) (8); E=Se, M=Ag, X=PF(6) (9); E=Se, M=Au, X=PF(6) (10)). Some of them display short metal.metal contacts. These complexes have been found to possess interesting luminescence properties. Through systematic comparison studies, the emission origin has been probed.     

Metastable Se6 as a ligand for Ag+: from isolated molecular to polymeric 1D and 2D structures

Attempts to prepare the hitherto unknown Se(6)(2+) cation by the reaction of elemental selenium and Ag[A] ([A](-) = [Sb(OTeF(5))(6)](-), [Al(OC(CF(3))(3))(4)](-)) in SO(2) led to the formation of [(OSO)Ag(Se(6))Ag(OSO)][Sb(OTeF(5))(6)](2)1 and [(OSO)(2)Ag(Se(6))Ag(OSO)(2)][Al(OC(CF(3))(3))(4)](2)2a. 1 could only be prepared by using bromine as co-oxidant, however, bulk 2b (2a with loss of SO(2)) was accessible from Ag[Al(OC(CF(3))(3))(4)] and grey Se in SO(2) (chem. analysis). The reactions of Ag[MF(6)] (M = As, Sb) and elemental selenium led to crystals of 1/∞{[Ag(Se(6))](∞)[Ag(2)(SbF(6))(3)](∞)} 3 and {1/∞[Ag(Se(6))Ag](∞)}[AsF(6)](2)4. Pure bulk 4 was best prepared by the reaction of Se(4)[AsF(6)](2), silver metal and elemental selenium. Attempts to prepare bulk 1 and 3 were unsuccessful. 1-4 were characterized by single-crystal X-ray structure determinations, 2b and 4 additionally by chemical analysis and 4 also by X-ray powder diffraction, FT-Raman and FT-IR spectroscopy. Application of the PRESTO III sequence allowed for the first time (109)Ag MAS NMR investigations of 4 as well as AgF, AgF(2), AgMF(6) and {1/∞[Ag(I(2))](∞)}[MF(6)] (M = As, Sb). Compounds 1 and 2a/b, with the very large counter ions, contain isolated [Ag(Se(6))Ag](2+) heterocubane units consisting of a Se(6) molecule bicapped by two silver cations (local D(3d) sym). 3 and 4, with the smaller anions, contain close packed stacked arrays of Se(6) rings with Ag(+) residing in octahedral holes. Each Ag(+) ion coordinates to three selenium atoms of each adjacent Se(6) ring. 4 contains [Ag(Se(6))(+)](∞) stacks additionally linked by Ag(2)(+) into a two dimensional network. 3 features a remarkable 3-dimensional [Ag(2)(SbF(6))(3)](-) anion held together by strong Sb-FAg contacts between the component Ag(+) and [SbF(6)](-) ions. The hexagonal channels formed by the [Ag(2)(SbF(6))(3)](-) anions are filled by stacks of [Ag(Se(6))(+)](∞) cations. Overall 1-4 are new members of the rare class of metal complexes of neutral main group elemental clusters, in which the main group element is positively polarized due to coordination to a metal ion. Notably, 1 to 4 include the commonly metastable Se(6) molecule as a ligand. The structure, bonding and thermodynamics of 1 to 4 were investigated with the help of quantum chemical calculations (PBE0/TZVPP and (RI-)MP2/TZVPP, in part including COSMO solvation) and Born-Fajans-Haber-cycle calculations. From an analysis of all the available data it appears that the formation of the usually metastable Se(6) molecule from grey selenium is thermodynamically driven by the coordination to the Ag(+) ions.     

Self-assembly of coordination polymers from AgX (X = SbF(6)(-), PF(6)(-), and CF(3)SO(3)(-)) and oxadiazole-containing ligands

The coordination chemistry of the oxadiazole-containing rigid bidentate ligands 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L1), 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L2), and 2,5-bis(3-aminophenyl)-1,3,4-oxadiazole (L3) with inorganic Ag(I) salts has been investigated. Four new coordination polymers (1, 2, 3, and 5) and one new bimetallic macrocyclic supramolecular complex (4) were synthesized from solution reactions of L1-L3 with inorganic Ag(I) salts, respectively. Compounds [[Ag(L1)]SbF(6)](n) (1) (1, monoclinic, P2(1)/c, a = 6.6846(4) A, b = 27.1113(15) A, c = 8.6802(5) A, beta = 94.1080(10) degrees, Z = 4) and [[Ag(L1)]PF(6)](n) (2) (2, monoclinic, P2(1)/c, a = 6.6753(3) A, b = 27.2824(14) A, c = 8.2932(4) A, beta = 94.6030(10) degrees, Z = 4) were obtained from the reactions of L1 with AgSbF(6) and AgPF(6) in a CH(2)Cl(2)/CH(3)OH mixed solvent system, respectively. Compounds 1 and 2 are isostructural and feature a novel two-dimensional zeolite-like net with two different individual rings. [[Ag(L2)]SbF(6)](n) (3) (3, monoclinic, P2(1)/c, a = 5.5677(3) A, b = 17.3378(9) A, c = 15.6640(8) A, beta = 94.4100(10) degrees, Z = 2) and [Ag(2)(L2)(2)](SbF(6))(2) (4) (4, triclinic, P1, a = 8.7221(5) A, b = 9.2008(6) A, c = 10.7686(7) A, alpha = 70.6270(10) degrees, beta = 75.7670(10) degrees, gamma = 73.7560(10) degrees, Z = 1) were obtained from one-pot reaction of L2 with AgSbF(6) in a CH(2)Cl(2)/CH(3)OH mixed solvent system. Compound 3 features a one-dimensional chain pattern, while compound 4 adopts a novel bimetallic macrocyclic structural motif which consists of Ag(2)(L2)(2) ringlike units (crystallographic dimensions, 8.06 x 7.42 A(2)). [[Ag(L3)]SO(3)CF(3)](n) (5) is generated from L3 and AgSO(3)CF(3) in a CH(2)Cl(2)/CH(3)OH mixed solvent system and crystallizes in the unusual space group Pbcn, with a = 9.8861(5) A, b = 20.2580(10) A, c = 17.5517(8) A, Z = 8. It adopts novel two-dimensional sheets that are cross-linked to each other by strong interlayer N-H...O hydrogen bonding interactions into a novel H-bonded three-dimensional network.     

New halide-centered discrete Ag(I)(8) cubic clusters containing diselenophosphate ligands, [Ag(8)(X)[Se(2)P(OR)(2)](6)](PF(6)) (X = Cl, Br; R = Et, Pr, (i)Pr): syntheses, structures, and DFT calculations

Six clusters Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)(PF(6)) (R = Et, X = Cl, 1a, X = Br, 1b; R = Pr, X = Cl, 2a, X = Br, 2b; R = (i)Pr, X = Cl, 3a, X = Br, 3b) were isolated from the reaction of [Ag(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NX in a molar ratio of 4:3:1 in CH(2)X(2). Positive FAB mass spectra show m/z peaks at 2573.2 for 1a, 2617.3 for 1b, 2740.9 for 2a, 2786.9 for 2b, 2742.3 for 3a, and 2787.0 for 3b due to respective molecular cation, (M - PF(6))(+). (31)P NMR spectra of 1a-3b display a singlet at delta 82.3, 81.5, 82.9, 81.7, 76.3, and 75.8 ppm with a set of satellites (J(PSe) = 661, 664, 652, 652, 656, and 656 Hz, respectively). The X-ray structure (1a-2b) consists of a discrete cationic cluster in which eight silver ions are linked by six diselenophosphate ligands and a central micro(8)-Cl or micro(8)-Br ion with a noncoordinating PF(6)(-) anion. The shape of the molecule is a halide-centered distorted Ag(8) cubic cluster. The dsep ligand exhibits a tetrametallic tetraconnective (micro(2), micro(2)) coordination pattern, and each caps on a square face of the cube. Each silver atom of the cube is coordinated by three selenium atoms and the central chloride or bromide ion. Additionally, molecular orbital calculations at the B3LYP level of the density functional theory have been carried out to study the Ag-micro(8)-X (X = Cl, Br) interactions for cluster cations [Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)](+). Calculations show very weak bonding interactions exist between micro(8)-X and Ag atoms of the cube.     

Synthesis and structure of coordination polymers of Ag(I) with isomeric (aminomethyl)pyridines. Formation of a novel circular helicate and 2-D networks via Ag...Ag contacts and coordination shell expansion under anion control

Reaction between Ag(I) salts and the three isomers of (aminomethyl)pyridines, viz., 2-amp, 3-amp, and 4-amp, lead to either discrete or polymeric (1-D and 2-D) structures influenced by anions and closed shell Ag.Ag contacts. Characterization data for Ag(2-amp)BF(4) (1) follow: monoclinic, space group C2/c, with a = 16.788(2) A, b = 11.5719(6) A, c = 11.3864(7) A, beta = 123.671(8) degrees, and Z = 8. For Ag(2)(2-amp)(3)(PF(6))(2) (2): monoclinic, space group P2(1)/a, with a = 10.029(7) A, b = 20.291(12) A, c = 13.907(6) A, beta = 95.38(5) degrees, and Z = 4. For Ag(2)(3-amp)(3)(PF(6))(2) (4): triclinic, space group P1, with a = 10.4482(7) A, b = 11.1468(9) A, c = 12.2720(11) A, alpha = 81.018(7) degrees, beta = 80.668(6) degrees, gamma = 80.977(6) degrees, and Z = 2. For Ag(4-amp)BF(4).0.75CH(3)CN (5): orthorhombic, space group C222(1), with a = 9.272(2) A, b = 16.164(12) A, c = 27.851(2) A, and Z = 8. For Ag(4-amp)PF(6) (6): monoclinic, space group P2(1)/m, with a = 5.2089(7) A, b = 14.3950(17) A, c = 7.0149(14) A, beta = 96.538(14) degrees, and Z = 2. While Ag(I) is 2-coordinate in 1, 5 and 6, it shows 3-coordination in 2 and 4. Compound 1 consists of a 1-D polymeric cation chain with interchain Ag...Ag contacts and the anions sitting on the edges of the chains. The dication in 2 is held in the form of a circular helicate by closed shell Ag...Ag interactions. Compound 4 generates a 2-D network with channels big enough to accommodate the anions. Compound 5 is a 2-D chiral network of chains connected by Ag...Ag contacts. Compound 6 shows a simple 1-D chain structure with an alternating arrangement of cationic chains and anions.     

Selenium imides: 77Se NMR investigations of the SeCl2-tBuNH2 reaction and X-ray structures of Se3(NtBu)3, tBuNSe(mu-NtBu)2SO2, and tBuNSe(mu-NtBu)2SeO

The reaction of SeCl2 with tert-butylamine in various molar ratios in THF at -78 degrees C has been investigated by 77Se NMR spectroscopy. In addition to the known Se-N heterocycles Se6(NtBu)2 (1) and Se9(NtBu)6 (2), the acyclic imidoselenium(II) dichlorides ClSe[N(tBu)Se]nCl (4, n = 1; 5, n = 2) and two new cyclic selenium imides [Se3(NtBu)2]n (3, n = 1 or 2) and Se3(NtBu)3 (6) have been isolated and identified. An X-ray analysis shows that 6 is a six-membered ring in a chair conformation with magnitude of d(Se-N) = 1.833 A. Crystal data: 6, trigonal, P3c1, a = 9.8660(3) A, c = 20.8427(7) A, V = 1757.0(1) A3, Z = 6. The 1H, 13C, and 77Se NMR data for 1-6 are reported, and some reassignments of earlier literature data for 1-3 (n = 1) are made. The decomposition of tBuN=Se=NtBu at 20 degrees C in toluene was monitored by 77Se NMR. The major products are 6 and 3. The Se(IV)-N systems tBuNSe(mu-NtBu)2E (7, E = SO2; 8, E = SeO) were prepared by the reaction of a mixture of SeCl4 and excess tBuNH2 with SO2Cl2 or SeOCl2, respectively. Compound 8 is also generated by the cycloaddition reaction of tBuNSeNtBu with tBuNSeO. Both 7 and 8 consist of slightly puckered four-membered rings. The mean terminal and bridging Se-N distances in 7 are 1.665(2) and 1.948(2) A, respectively. The corresponding values for 8 are 1.687(4) and 1.900(4) A, and d(Se=O) = 1.628(4) A. Crystal data: 7, monoclinic, P2(1)/c, a = 18.669(4) A, b = 12.329(2) A, c = 16.463(3) A, beta = 115.56(3) degrees, V = 3418.4(11) A3, Z = 4; 8, triclinic, P1, a = 6.372(1) A, b = 9.926(2) A, c = 14.034(3) A, alpha = 99.320(3) A, beta = 95.764(3) A, gamma = 103.876(3) A, V = 841.3(3) A3, Z = 2.     

A Comparative Study of Two New Structure Types. Synthesis and Structural and Electronic Characterization of K(RE)P(2)Se(6) (RE = Y, La, Ce, Pr, Gd)

Two polytypes of potassium rare-earth-metal hexaselenodiphosphates(IV), K(RE)P(2)Se(6) (RE = Y, La, Ce, Pr, Gd), have been synthesized from the stoichiometric reaction of RE, P, Se, and K(2)Se(4) at 750 degrees C. Both single-crystal and powder X-ray diffraction analyses showed that the structures of these polytypes vary with the size of the rare earth metals. For the smaller rare-earth metals, Y and Gd, K(RE)P(2)Se(6) crystallized in the orthorhombic space group P2(1)2(1)2(1). The yttrium compound was studied by single-crystal X-ray diffraction with the cell parameters a = 6.7366(5) ?, b = 7.4286(6) ?, c = 21.603(2) ?, and Z = 4. This structure type comprises a layered, square network of yttrium atoms that are bound to four distinct [P(2)Se(6)](4)(-) units through selenium bonding. Each [P(2)Se(6)](4)(-) unit possesses a Se atom that is not bound to any Y atom but is pointing out into the interlayer spacing, into an environment of potassium cations. For larger rare-earth metals, La, Ce, and Pr, K(RE)P(2)Se(6) crystallized in a second, monoclinic polytype, the structure of which has been published. Both of these two different polytypes can be related to each other and several other isoelectronic chalcophosphate structures based on a Parthé valence electron concentration analysis. These structures include Ag(4)P(2)S(6), K(2)FeP(2)S(6), and the hexagonal M(II)PS(3) structure types. The magnetic susceptibilities of the title compounds have been studied, and the behavior can been explained based on a simple set of unpaired f-electrons. The diffuse reflectance spectroscopy also showed that these yellow plates are moderately wide band gap ( approximately 2.75 eV) semiconductors.     

A Two-dimensional Metallic Oxide Constructed from Molybdenum Clusters and Ag（Ⅰ）-[3-（2-pyridyl）-pyrazole] Cationic Coordination Components

A new polyoxomolybdate compound [Ag 3 (HL) 4 ](PMo 12 O 40)] 1 (HL=3-(2-pyridyl)pyrazole) has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in triclinic,space group P1 with a=10.375(3),b=12.076(3),c=13.196(4),α=84.170(4),β=71.961(3),γ=86.326(4)°,V=1563.1(7)3,C 32 H 28 Ag 3 Mo 12 N 12 O 40 P,M r=2726.52,D c=2.897 g/cm 3,μ(MoKα)=3.366 mm 1,F(000)=1284,Z=1,the final R=0.0587 and wR=0.1312 for 4139 observed reflections (I > 2σ(Ⅰ)).X-ray diffraction analyses reveal that the PMo 12 O 40 3clusters in compound 1 are linked by four Ag 3 (HL) 4 3+ units via the terminal oxygen atoms to form a two-dimensional architecture.The symmetrical unit of Ag 3 (HL) 4 3+ exhibits two distinct Ag(Ⅰ) environments:a two-coordinate {AgN 2 } site and a five-coordinate {AgN 3 O 2 } site which links to two molybdate clusters.     

Organometallic coordination polymers generated from bent Bis(acetylenylphenyl)oxadiazole ligands and Ag(I) salts

Two new bent oxadiazole bridging benzoacetylene ligands 2,5-bis(4-ethynylphenyl)-1,3,4-oxadiazole (L9) and 2,5-bis(3-ethynylphenyl)-1,3,4-oxadiazole (L10) were synthesized. The coordination chemistry of them with various inorganic Ag(I) salts has been investigated. Seven new coordination polymers were prepared by solution reactions and fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. [Ag2(L9)](SO3CF3)2 (1) (triclinic, P; a =10.292(4), b = 10.794(4), c = 11.399(5) A; alpha = 98.894(5), beta = 102.360(6), gamma = 90.319(5) degrees ; Z = 2), [Ag(L9)]SbF6 (2) (orthorhombic, Cmca; a = 19.059(9), b = 12.922(6), c = 15.609(7) A; Z = 8), [Ag(L9)]BF4 (3) (orthorhombic, Cmca; a = 19.128(3), b = 12.6042(18), c = 28.003(4) A; Z = 16), [Ag(L9)]ClO4 (4) (monoclinic, P2(1)/c; a = 8.5153(16), b = 19.722(4), c = 10.320(2) A; beta = 105.307(3) degrees ; Z = 4), [Ag(L10)]SO3CF3 (5) (triclinic, P; a = 9.0605(13), b = 10.4956(15), c = 10.8085(16) A; alpha = 101.666(2), beta = 109.269(2), gamma = 100.944(2) degrees ; Z = 2), [Ag(L10)(H2O)(0.5)]BF4.0.5H2O (6) (monoclinic, C2/m; a = 32.180(6), b = 17.027(3), c = 8.1453(15) A; beta = 102.541(3) degrees ; Z = 8), and {[Ag2(L10)2(H2O)](ClO4)2}.o-xylene (7) (monoclinic, P2(1)/c; a = 8.1460(10), b = 17.326(2), c = 30.345(4) A; beta = 97.71 degrees ; Z = 4) were obtained by the combination of L9 and L10 with various Ag(I) salts in a benzene/methylene chloride mixed solvent system. In addition, the luminescent and electrical conductive properties of these new compounds were investigated.