Synthesis, characterization and magnetic properties of four new organically templated metal sulfates [C5H14N2][M(II)(H2O)6](SO4)2, (M(II) = Mn, Fe, Co, Ni)

A series of novel organically templated metal sulfates, [C(5)H(14)N(2)][M(II)(H(2)O)(6)](SO(4))(2) with (M(II) = Mn (1), Fe (2), Co (3) and Ni (4)), have been successfully synthesized by slow evaporation and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, thermogravimetric analysis and magnetic measurements. All compounds were prepared using a racemic source of the 2-methylpiperazine and they crystallized in the monoclinic systems, P2(1)/n for (1, 3) and P2(1)/c for (2,4). Crystal data are as follows: [C(5)H(14)N(2)][Mn(H(2)O)(6)](SO(4))(2), a = 6.6385(10) ?, b = 11.0448(2) ?, c = 12.6418(2) ?, β = 101.903(10)°, V = 906.98(3) ?(3), Z = 2; [C(5)H(14)N(2)][Fe(H(2)O)(6)](SO(4))(2), a = 10.9273(2) ?, b = 7.8620(10) ?, c = 11.7845(3) ?, β = 116.733(10)°, V = 904.20(3) ?(3), Z = 2; [C(5)H(14)N(2)][Co(H(2)O)(6)](SO(4))(2), a = 6.5710(2) ?, b = 10.9078(3) ?, c = 12.5518(3) ?, β = 101.547(2)°, V = 881.44(4) ?(3), Z = 2; [C(5)H(14)N(2)][Ni(H(2)O)(6)](SO(4))(2), a = 10.8328(2) ?, b = 7.8443(10) ?, c = 11.6790(2) ?, β = 116.826(10)°, V = 885.63(2) ?(3), Z = 2. The three-dimensional structure networks for these compounds consist of isolated [M(II)(H(2)O)(6)](2+) and [C(5)H(14)N(2)](2+) cations and (SO(4))(2-) anions linked by hydrogen-bonds only. The use of racemic 2-methylpiperazine results in crystallographic disorder of the amines and creation of inversion centers. The magnetic measurements indicate that the Mn complex (1) is paramagnetic, while compounds 2, 3 and 4, (M(II) = Fe, Co, Ni respectively) exhibit single ion anisotropy.     

Spectroscopic and magnetic properties of a series of μ-cyano bridged bimetallic compounds of the type M(II)-NC-Fe(III) (M = Mn, Co, and Zn) using the building block [Fe(III)(CN)5imidazole]2-

In this contribution, we describe the preparation and single-crystal X-ray diffraction of a new building block for bimetallic solid state materials. X-ray diffraction data of these complexes indicate that (PPh(4))(2)[Fe(CN)(5)imidazole]·2H(2)O crystallizes in the triclinic space group P1 with a = 9.8108(15) ?, b = 11.1655(17) ?, c = 23.848(4) ?, α = 87.219(2)°, β = 85.573(2)°, γ = 70.729(2)°, and Z = 2, while its precursor Na(3)[Fe(CN)(5)(en)]·5H(2)O crystallizes in the monoclinic space group P2(1)/n with a = 8.3607(7) ?, b = 11.1624(9) ?, c = 17.4233(14) ?, β = 90.1293(9)°, and Z = 4. Spectroscopic and magnetic properties of a series of bimetallic materials were obtained by reaction of the complex [Fe(CN)(5)imidazole](2-) with hydrated transition metal ions [M(H(2)O)(n)](2+) (M = Mn, Co, Zn; n = 4 or 6). The new bimetallic materials obtained are [Co(H(2)O)(2)][Fe(CN)(5)imidazole]·2H(2)O (1), [Mn(CH(3)OH)(2)][Fe(CN)(5)imidazole] (2), Zn[Fe(CN)(5)imidazole]·H(2)O (3), and [Mn(bpy)][Fe(CN)(5)imidazole].H(2)O (4). All of the complexes crystallize in the orthorhombic system. X-ray single-crystal analysis of the compounds identified the Imma space group with a = 7.3558(10) ?, b = 14.627(2) ?, c = 14.909(2) ?, and Z = 4 for 1; the P2(1)2(1)2(1) space group with a = 7.385(5) ?, b = 13.767(9) ?, c = 14.895(10) ?, and Z = 4 for 2; the Pnma space group with a = 13.783(2) ?, b = 7.167(11) ?, c = 12.599(2) ?, and Z = 4 for 3; and the Pnma space group with a = 13.192(3) ?, b = 7.224(16) ?, c = 22.294(5) ?, and Z = 4 for 4. The structures of 1, 2, and 4 consist of two-dimensional network layers containing, as the repeating unit, a cyclic tetramer [M(2)Fe(2)(CN)(4)] (M = Mn, Co). H bonding between the layers in the structure of 1 results in a quasi-three-dimensional network. The structure of 3 was found to be three-dimensional, where all of the cyano ligands are involved in bridging between the metal centers. The bridging character of the cyano is confirmed spectroscopically. The magnetic properties have been investigated for all of the bimetallic systems. Compound 1 shows ferromagnetic behavior with an ordering temperature at 25 K, which is higher than the corresponding Prussian Blue analogue Co(x)[Fe(CN)(6)](y)?·zH(2)O. Compound 2 shows weak ferromagnetic behavior and an interlayer antiferromagnetic character, while 3, as expected, shows paramagnetic character due to the diamagnetic character of Zn(2+). Compound 4 shows antiferromagnetic behavior.     

Mercuric ionic liquids: [C(n)mim][HgX3], where n = 3, 4 and X = Cl, Br

A series of mercury(II) ionic liquids, [C(n)mim][HgX(3)], where [C(n)mim] = n-alkyl-3-methylimidazolium with n = 3, 4 and X = Cl, Br, have been synthesized following two different synthetic approaches, and structurally characterized by means of single-crystal X-ray structure analysis ([C(3)mim][HgCl(3)] (1), Cc (No. 9), Z = 4, a = 16.831(4) ?, b = 10.7496(15) ?, c = 7.4661(14) ?, β = 105.97(2)°, V = 1298.7(4) ?(3) at 298 K; [C(4)mim][HgCl(3)] (2), Cc (No. 9), Z = 4, a = 17.3178(28) ?, b = 10.7410(15) ?, c = 7.4706(14) ?, β = 105.590(13)°, V = 1338.5(4) ?(3) at 170 K; [C(3)mim][HgBr(3)] (3), P2(1)/c (No. 14), Z = 4, a = 10.2041(10) ?, b = 10.7332(13) ?, c = 14.5796(16) ?, β = 122.47(2)°, V = 1347.2(3) ?(3) at 170 K; [C(4)mim][HgBr(3)] (4), Cc (No. 9), Z = 4, a = 17.093(3) ?, b = 11.0498(14) ?, c = 7.8656(12) ?, β = 106.953(13)°, V = 1421.1(4) ?(3) at 170 K). Compounds 1, 2, and 4 are isostructural and are characterized by strongly elongated trigonal [HgX(5)] bipyramids, which are connected via common edges in chains. In contrast, 3 contains [Hg(2)Br(6)] units formed by two edge-sharing tetrahedra. With melting points of 69.3 °C (1), 93.9 °C (2), 39.5 °C (3), and 58.3 °C (4), all compounds qualify as ionic liquids. 1, 2, and 4 solidify upon fast cooling as glasses, whereas 3 crystallizes. Cyclic voltammetry shows two separate, quasi-reversible redox processes, which can be associated with the 2Hg(2+)/Hg(2)(2+) and Hg(2)(2+)/2Hg redox couples.     

Metal-centered deltahedral Zintl ions: synthesis of [Ni@Sn9]4- by direct extraction from intermetallic precursors and of the vertex-fused dimer [{Ni@Sn8(μ-Ge)(1/2)}2]4-

Ni-centered deltahedral Sn(9) clusters with a charge of 4-, i.e., [Ni@Sn(9)](4-), were extracted in ethylenediamine in high yield directly from intermetallic precursors with the nominal composition "K(4)Sn(9)Ni(3)". The new endohedral clusters were crystallized and structurally characterized in K[K(18-crown-6)](3)[Ni@Sn(9)]·3benzene (1a, triclinic, P1?, a = 10.2754(5) ?, b = 19.5442(9) ?, and c = 20.5576(13) ?, α = 73.927(3)°, β = 79.838(4)°, and γ = 84.389(3)°, V = 3899.6(4) ?(3), Z = 2) and K[K(2,2,2-crypt)](3)[Ni@Sn(9)] (1b, triclinic, P1, a = 15.8028(8) ?, b = 16.21350(9) ?, and c = 20.1760(12) ?, α = 98.71040(10)°, β = 104.4690(10)°, and γ = 118.3890(10)°, V = 4181.5(4) ?(3), Z = 2). The alternative method of a post-synthetic insertion of a Ni atom in empty Sn(9) clusters by a reaction with Ni(cod)(2) predominantly produces the more-oxidized clusters with a charge of 3-, i.e., the recently reported [Ni@Sn(9)](3-). Nonetheless, using substoichiometric amounts of 18-crown-6 as a cation sequestering agent, we also have been able to isolate the 4- clusters as a minor phase from such reactions. They were structurally characterized in K[K(en)][K(18-crown-6)](2)[Ni@Sn(9)]·0.5en (2, monoclinic, P2(1)/n, a = 10.4153(5) ?, b = 25.6788(11) ?, and c = 20.6630(9) ?, β = 102.530(2)°, V = 5394.7(4) ?(3), Z = 2). The ability of the Ni-centered clusters to exist with both 3- and 4- charges parallels the same ability of the empty clusters and is very promising for similarly rich chemistry involving electron transfer and flexible "oxidation states". We also report the synthesis and characterization of the endohedral heteroatomic dimer [{Ni@Sn(8)(μ-Ge)(1/2)}(2)](4-) composed of two [Ni@(Sn(8)Ge)]-clusters fused at the Ge-vertex. The dimer was synthesized by reacting an ethylenediamine solution of a ternary precursor with the nominal composition "K(4)Ge(4.5)Sn(4.5)", which is known to produce heteroatomic Ge(9-x)Sn(x) clusters, with Ni(cod)(2). It is isostructural with the reported [{Ni@Sn(8)(μ-Sn)(1/2)}(2)](4-) and is structurally characterized in [K-(2,2,2-crypt)](4)[{Ni@Sn(8)(μ-Ge)(1/2)}(2)]·2en (3, monoclinic, C2/c, a = 30.636(2) ?, b = 16.5548(12) ?, and c = 28.872(2) ?, β = 121.2140(10)°, V = 12523.5(15) ?(3), Z = 4).     

New binuclear Mn(II) and Fe(II) complexes supported by 1,4,8-triazacycloundecane

Two new binuclear metal complexes supported by 1,4,8-triazacycloundecane (tacud) are reported. [Fe(2)(tacud)(2)(μ-Cl)(2)Cl(2)] (1) and [Mn(2)(tacud)(2)(μ-Cl)(2)Cl(2)] (2) are isomorphs consisting of bis(μ-chloro) bridged metal centers along with terminal chloro groups and tacud ligands. Both compounds 1 and 2 crystallize in the P1 space group. For 1, a = 7.7321(12) ?, b = 7.8896(12) ?, c = 11.4945(17) ?, α = 107.832(2)°, β = 107.827(2)°, γ = 92.642(2)°, V = 627.85(17) ?(3) and Z = 1. For 2, a = 7.7607(12) ?, b = 7.9068(12) ?, c = 11.6111(18) ?, α = 108.201(2)°, β = 108.041(2)°, γ = 92.118(3)°, V = 636.47(17) ?(3) and Z = 1. Variable-temperature and variable-field magnetic susceptibility studies on 1 indicate the presence of weak ferromagnetic interactions between the high-spin iron(ii) centers in the dimer (J = + 1.6 cm(-1)) and the crystalline field anisotropy of the ferrous ion (D = - 2.8, E = - 0.1 cm(-1)). Variable temperature magnetic susceptometry studies on 2 indicate that weak antiferromagnetic coupling exists between the manganese(ii) centers (J = - 1.8 cm(-1)). Compounds 1 and 2 retain their dinuclearity in weakly coordinating or low polarity solvents, while both become mononuclear in solvents such as methanol.     

The series of molecular conductors and superconductors ET4[AFe(C2O4)3]·PhX (ET = bis(ethylenedithio)tetrathiafulvalene; (C2O4)2- = oxalate; A+ = H3O+, K+; X = F, Cl, Br, and I): influence of the halobenzene guest molecules on the crystal structure and superconducting properties

An extensive series of radical salts formed by the organic donor bis(ethylenedithio)tetrathiafulvalene (ET), the paramagnetic tris(oxalato)ferrate(III) anion [Fe(C(2)O(4))(3)](3-), and halobenzene guest molecules has been synthesized and characterized. The change of the halogen atom in this series has allowed the study of the effect of the size and charge polarization on the crystal structures and physical properties while keeping the geometry of the guest molecule. The general formula of the salts is ET(4)[A(I)Fe(C(2)O(4))(3)]·G with A/G = H(3)O(+)/PhF (1); H(3)O(+)/PhCl (2); H(3)O(+)/PhBr (3), and K(+)/PhI (4), (crystal data at room temperature: (1) monoclinic, space group C2/c with a = 10.3123(2) ?, b = 20.0205(3) ?, c = 35.2732(4) ?, β = 92.511(2)°, V = 7275.4(2) ?(3), Z = 4; (2) monoclinic, space group C2/c with a = 10.2899(4) ?, b = 20.026(10) ?, c = 35.411(10) ?, β = 92.974°, V = 7287(4) ?(3), Z = 4; (3) monoclinic, space group C2/c with a = 10.2875(3) ?, b = 20.0546(15) ?, c = 35.513(2) ?, β = 93.238(5)°, V = 7315.0(7) ?(3), Z = 4; (4) monoclinic, space group C2/c with a = 10.2260(2) ?, b = 19.9234(2) ?, c = 35.9064(6) ?, β = 93.3664(6)°, V = 7302.83(18) ?(3), Z = 4). The crystal structures at 120 K evidence that compounds 1-3 undergo a structural transition to a lower symmetry phase when the temperature is lowered (crystal data at 120 K: (1) triclinic, space group P1 with a = 10.2595(3) ?, b = 11.1403(3) ?, c = 34.9516(9) ?, α = 89.149(2)°, β = 86.762(2)°, γ = 62.578(3)°, V = 3539.96(19) ?(3), Z = 2; (2) triclinic, space group P1 with a = 10.25276(14) ?, b = 11.15081(13) ?, c = 35.1363(5) ?, α = 89.0829(10)°, β = 86.5203(11)°, γ = 62.6678(13)°, V = 3561.65(8) ?(3), Z = 2; (3) triclinic, space group P1 with a = 10.25554(17) ?, b = 11.16966(18) ?, c = 35.1997(5) ?, α = 62.7251(16)°, β = 86.3083(12)°, γ = 62.7251(16)°, V = 3575.99(10) ?(3), Z = 2; (4) monoclinic, space group C2/c with a = 10.1637(3) ?, b = 19.7251(6) ?, c = 35.6405(11) ?, β = 93.895(3)°, V = 7128.7(4) ?(3), Z = 4). A detailed crystallographic study shows a change in the symmetry of the crystal for compound 3 at about 200 K. This structural transition arises from the partial ordering of some ethylene groups in the ET molecules and involves a slight movement of the halobenzene guest molecules (which occupy hexagonal cavities in the anionic layers) toward one of the adjacent organic layers, giving rise to two nonequivalent organic layers at 120 K (compared to only one at room temperature). The structural transition at about 200 K is also observed in the electrical properties of 1-3 and in the magnetic properties of 1. The direct current (dc) conductivity shows metallic behavior in salts 1-3 with superconducting transitions at about 4.0 and 1.0 K in salts 3 and 1, respectively. Salt 4 shows a semiconductor behavior in the temperature range 300-50 K with an activation energy of 64 meV. The magnetic measurements confirm the presence of high spin S = 5/2 [Fe(C(2)O(4))(3)](3-) isolated monomers together with a Pauli paramagnetism, typical of metals, in compounds 1-3. The magnetic properties can be very well reproduced in the whole temperature range with a simple model of isolated S = 5/2 ions with a zero field splitting plus a temperature independent paramagnetism (Nα) with the following parameters: g = 1.965, |D| = 0.31 cm(-1), and Nα = 1.5 × 10(-3) emu mol(-1) for 1, g = 2.024, |D| = 0.65 cm(-1), and Nα = 1.4 × 10(-3) emu mol(-1) for 2, and g = 2.001, |D| = 0.52 cm(-1), and Nα = 1.5 × 10(-3) emu mol(-1) for 3.     

Hydrolysis studies on bismuth nitrate: synthesis and crystallization of four novel polynuclear basic bismuth nitrates

Hydrolysis of Bi(NO(3))(3) in aqueous solution gave crystals of the novel compounds [Bi(6)O(4)(OH)(4)(NO(3))(5)(H(2)O)](NO(3)) (1) and [Bi(6)O(4)(OH)(4)(NO(3))(6)(H(2)O)(2)]·H(2)O (2) among the series of hexanuclear bismuth oxido nitrates. Compounds 1 and 2 both crystallize in the monoclinic space group P2(1)/n but show significant differences in their lattice parameters: 1, a = 9.2516(6) ?, b = 13.4298(9) ?, c = 17.8471(14) ?, β = 94.531(6)°, V = 2210.5(3) ?(3); 2, a = 9.0149(3) ?, b = 16.9298(4) ?, c = 15.6864(4) ?, β = 90.129(3)°, V = 2394.06(12) ?(3). Variation of the conditions for partial hydrolysis of Bi(NO(3))(3) gave bismuth oxido nitrates of even higher nuclearity, [{Bi(38)O(45)(NO(3))(24)(DMSO)(26)}·4DMSO][{Bi(38)O(45)(NO(3))(24)(DMSO)(24)}·4DMSO] (3) and [{Bi(38)O(45)(NO(3))(24)(DMSO)(26)}·2DMSO][{Bi(38)O(45)(NO(3))(24)(DMSO)(24)}·0.5DMSO] (5), upon crystallization from DMSO. Bismuth oxido clusters 3 and 5 crystallize in the triclinic space group P1? both with two crystallographically independent molecules in the asymmetric unit. The following lattice parameters are observed: 3, a = 20.3804(10) ?, b = 20.3871(9) ?, c = 34.9715(15) ?, α = 76.657(4)°, β = 73.479(4)°, γ = 60.228(5)°, V = 12021.7(9) ?(3); 5, a = 20.0329(4) ?, b = 20.0601(4) ?, c = 34.3532(6) ?, α = 90.196(1)°, β = 91.344(2)°, γ = 119.370(2)°, V = 12025.8(4) ?(3). Differences in the number of DMSO molecules (coordinated and noncoordinated) and ligand (nitrate, DMSO) coordination modes are observed.     

Aluminosilicate relatives: Chalcogenoaluminogermanates Rb(3)(AlQ(2))(3)(GeQ(2))(7) (Q = S, Se)

The new compounds Rb(3)(AlQ(2))(3)(GeQ(2))(7) [Q = S (1), Se (2)] feature the 3D anionic open framework [(AlQ(2))(3)(GeQ(2))(7)](3-) in which aluminum and germanium share tetrahedral coordination sites. Rb ions are located in channels formed by the connection of 8, 10, and 16 (Ge/Al)S(4) tetrahedra. The isostructural sulfur and selenium derivatives crystallize in the space group P2(1)/c. 1: a = 6.7537(3) ?, b = 37.7825(19) ?, c = 6.7515(3) ?, and β = 90.655(4)°. 2: a = 7.0580(5) ?, b = 39.419(2) ?, c = 7.0412(4) ?, β = 90.360(5)°, and Z = 2 at 190(2) K. The band gaps of the congruently melting chalcogenogermanates are 3.1 eV (1) and 2.4 eV (2).     

H(x)TeV9O28]((5-x)-) (x=1 and 2): vanadotellurates with decavanadate structure

Two new vanadotellurates, [HTeV(9)O(28)](4-) and [H(2)TeV(9)O(28)](3-) have been synthesized and structurally characterized as tetra-n-butylammonium (TBA) salts: TBA(4)[HTeV(9)O(28)]·2CH(3)CN [triclinic, space group P ?1, a = 16.7102(6) ?, b = 17.4680(7) ?, c = 17.9634(7) ?, α = 74.412(1)°, β = 67.494(1)°, γ = 74.160(2)°, Z = 2] and TBA(3)[H(2)TeV(9)O(28)] [monoclinic, space group P2(1)/c, a = 13.0013(5) ?, b = 19.157(1) ?, c = 28.453(1) ?, β = 97.222(2)°, Z = 4]. The results of the structural analyses indicate that the four O atoms that bridge two V atoms on the Te side are the most basic ones in the structure. The results of density-functional theory (DFT) calculations support this view.     

Manganese(II/II/II) and Manganese(III/II/III) Trinuclear Compounds. Structure and Solid and Solution Behavior

Two mixed-valence Mn(III)Mn(II) complexes and a homo-valence Mn(II) trinuclear manganese complex of stoichiometry Mn(III)Mn(II)Mn(III)(5-Cl-Hsaladhp)(2)(AcO)(4)(MeOH)(2).4CH(3)OH (1a), Mn(III)Mn(II)Mn(III) (Hsaladhp)(2)(AcO)(2)(5-Cl-Sal)(2)(thf)(2) (3a) and Mn(II)Mn(II)Mn(II) (AcO)(6)(pybim)(2) (1b) where H(3)saladhp is a tridentate Schiff base ligand and pybim a neutral bidentate donor ligand, have been structurally characterized by using X-ray crystallography. The structurally characterized mixed-valence complexes have strictly 180 degrees Mn(III)-Mn(II)-Mn(III) angles as required by crystallographic inversion symmetry. The complexes are valence trapped with two terminal Mn(III) ions showing Jahn-Teller distortion along the acetate or salicylate-Mn(III)-X axis. The Mn.Mn separation is 3.511 ? and 3.507 ? respectively. The mixed-valence complexes have S = (3)/(2) ground state and the homovalence complex S = (5)/(2), with small antiferromagnetic exchange J couplings, -5.6 and -1.8 cm(-1), respectively, while the powder ESR spectra at 4 K show a broad low field signal with g approximately 4.3 for Mn(III)Mn(II)Mn(III) and a broad temperature-dependent signal at g = 2 for Mn(II)Mn(II)Mn(II). Crystal data for 1a: [C(36)H(60)O(20)N(2)Cl(2)Mn(3)], triclinic, space group P&onemacr;, a = 9.272(7) ?, b = 11.046(8) ?, c = 12.635(9) ?, alpha = 76.78(2) degrees, beta = 81.84(2) degrees, gamma = 85.90(2) degrees, Z = 1. Crystal data for 3a: [C(48)H(56)O(18)N(2)Cl(2)Mn(3)], monoclinic, space group P2(1)/n, a = 8.776(3) ?, b = 22.182(7) ?, c = 13.575(4) ?, beta = 94.44(1) degrees, Z = 2. Crystal data for 1b: [C(36)H(36)O(12)N(6)Mn(3)], triclinic, space group P&onemacr;, a = 13.345(6) ?, b = 8.514(4) ?, c = 9.494(4) ?, alpha = 75.48(1) degrees, beta = 75.83(1) degrees, gamma = 76.42(1) degrees, Z = 1.     

Contribution of disulfide S2(2-) anions to the crystal and electronic structures in ternary sulfides, Ba12In4S19, Ba4M2S8 (M=Ga, In)

Three semiconducting ternary sulfides have been synthesized from the mixture of elements with about 20% excess of sulfur (to establish oxidant rich conditions) by solid-state reactions at high temperature. Ba(12)In(4)S(19) ≡ (Ba(2+))(12)(In(3+))(4)(S(2-))(17)(S(2))(2-), 1, crystallizes in the trigonal space group R ?3 with a = 9.6182(5) ?, b = 9.6182(5) ?, c = 75.393(7) ?, and Z = 6, with a unique long period-stacking structure of a combination of monometallic InS(4) tetrahedra, linear dimeric In(2)S(7) tetrahedra, disulfide S(2)(2-) anions, and isolated sulfide S(2-) anions that is further enveloped by Ba(2+) cations. Ba(4)In(2)S(8) ≡ (Ba(2+))(4)(In(3+))(2)(S(2-))(6)(S(2))(2-), 2, crystallizes in the triclinic space group P ?1? with a = 6.236(2) ?, b = 10.014(4) ?, c = 13.033(5) ?, α = 104.236(6)°, β = 90.412(4)°, γ = 91.052(6)°, and Z = 2. Ba(4)Ga(2)S(8) ≡ (Ba(2+))(4)(Ga(3+))(2)(S(2-))(6)(S(2))(2-), 3, crystallizes in the monoclinic P2(1)/c with a = 12.739(5) ?, b = 6.201(2) ?, c = 19.830(8) ?, β = 104.254(6)° and Z = 4. Compounds 2 and 3 represent the first one-dimensional (1D) chain structure in ternary Ba/M/S (M = In, Ga) systems. The optical band gaps of 1 and 3 are measured to be around 2.55 eV, which agrees with their yellow color and the calculation results. The CASTEP calculations also reveal that the disulfide S(2)(2-) anions in 1-3 contribute mainly to the bottom of the conduction bands and the top of valence bands, and thus determine the band gaps.     

A new organic-inorganic hybrid layered molybdenum(V) cobalt phosphate constructed from [H24(Mo16O32)Co16(PO4)24(OH)4(C5H4N)2(H2O)6](4-) wheels and 4,4'-bipyridine linkers

A new layered molybdenum cobalt phosphate, Na(2)[Co(H(2)O)(6)][(Mo(16)O(32))Co(16)(PO(4))(4) (HPO(4))(16)(H(2)PO(4))(4)(OH)(4)(C(10)H(8)N(2))(4)(C(5)H(4)N)(2)(H(2)O)(6)]·4H(2)O (1), has been hydrothermally synthesized and structurally characterized. 1 crystallizes in the monoclinic space group P2(1)/n with a = 15.6825(18) ?, b = 39.503(4) ?, c = 17.2763(17) ?, β = 93.791(2)°, V = 10679.4(18) ?(3), and Z = 2. A polyoxoanion of 1 exhibits an unusual organic-inorganic hybrid wheel-type cluster, in which two pyridine ligands link to the surface Co(II) atoms of a [H(24)(Mo(16)O(32))Co(16)(PO(4))(24)(OH)(4)(H(2)O)(6)] (namely, {Mo(16)Co(16)P(24)}) wheel via the Co-N bonds. Furthermore, each {Mo(16)Co(16)P(24)} wheel is connected to four adjacent wheels by four pairs of 4,4'-bipyridine linkers, forming a 2D layered network. The susceptibility measurement shows the existence of dominant antiferromagnetic interactions in 1.     

Syntheses and Crystal Structures of Molybdenum-Sulfur Clusters Mo_3S_4 (dtp)_3(o-CH_3OC_6H_4COO)(Py) and Mo_3S_4 (dtp)_3(p-HOC_6H_4COO)(DMF)·EtOH

1 INTRODUCTION Recent years have seen a drastic increase of compounds containing the Mo3S4 core. A major synthetic route to these compounds is by the reaction of the aqua ion [Mo3S4(H2O)9]4+ with different kinds of ligands replacing some or all of the water molecules. In this way, Mo3S4(dtp)4(H2O), which was synthesized by the spontaneous- assembly method in 1986[1] and its structural characterization and chemical reactivity have been well recognized [2], can be rationally synthesize…     

Sulfates of the refractory metals: crystal structure and thermal behavior of Nb2O2(SO4)3, MoO2(SO4), WO(SO4)2, and two modifications of Re2O5(SO4)2

The sulfates Nb(2)O(2)(SO(4))(3), MoO(2)(SO(4)), WO(SO(4))(2,) and two modifications of Re(2)O(5)(SO(4))(2) have been synthesized by the solvothermal reaction of NbCl(5), WOCl(4), Re(2)O(7)(H(2)O)(2), and MoO(3) with sulfuric acid/SO(3) mixtures at temperatures between 200 and 300 °C. Besides the X-ray crystal structure determination of all compounds, the thermal behavior was investigated using thermogravimetric studies. WO(SO(4))(2) (monoclinic, P2(1)/n, a = 7.453(1) ?, b = 11.8232(8) ?, c = 7.881(1) ?, β = 107.92(2)°, V = 660.7(1) ?(3), Z = 4) and both modifications of Re(2)O(5)(SO(4))(2) (I: orthorhombic, Pba2, a = 9.649(1) ?, b = 8.4260(8) ?, c = 5.9075(7) ?, V = 480.27(9) ?(3), Z = 2; II: orthorhombic, Pbcm, a = 7.1544(3) ?, b = 7.1619(3) ?, c = 16.8551(7) ?, V = 863.64(6) ?(3), Z = 4) are the first structurally characterized examples of tungsten and rhenium oxide sulfates. Their crystal structure contains layers of sulfate connected [W═O] moieties or [Re(2)O(5)] units, respectively. The cohesion between layers is realized through weak M-O contacts (343-380 pm). Nb(2)O(2)(SO(4))(3) (orthorhombic, Pna2(1), a = 9.9589(7) ?, b = 11.7983(7) ?, c = 8.6065(5) ?, V = 1011.3(1) ?(3), Z = 4) represents a new sulfate-richer niobium oxide sulfate. The crystal structure contains a three-dimensional network of sulfate connected [Nb═O] moieties. In MoO(2)(SO(4)) (monoclinic, I2/a, a = 8.5922(6) ?, b = 12.2951(6) ?, c = 25.671(2) ?, β = 94.567(9)°, V = 2703.4(3) ?(3), Z = 24) [MoO(2)] units are connected through sulfate ions to a three-dimensional network, which is pervaded by channels along [100] accommodating the terminal oxide ligands. In all compounds except WO(SO(4))(2), the metal ions are octahedrally coordinated by monodentate sulfate ions and oxide ligands forming short M═O bonds. In WO(SO(4))(2), the oxide ligand and two monodentate and two bidentate sulfate ions build a pentagonal bipyramid around W. The thermal stability of the sulfates decreases in the order Nb > Mo > W > Re; the residues formed during the decomposition are the corresponding oxides.     

The Uracil C(5) Position as a Metal Binding Site: Solution and X-ray Crystal Structure Studies of Pt(II) and Hg(II) Compounds

1,3-Dimethyluracil (1,3-DimeU) reacts with trans-[(CH(3)NH(2))(2)Pt(H(2)O)(2)](+) to give trans-[(CH(3)NH(2))(2)Pt(1,3-DimeU-C5)(H(2)O)]X (X = NO(3)(-), 1a, ClO(4)(-), 1b) and subsequently with NaCl to give trans-(CH(3)NH(2))(2)Pt(1,3-DimeU-C5)Cl (2) or with NH(3) to yield trans-[(CH(3)NH(2))(2)Pt(1,3-DimeU-C5)(NH(3))]ClO(4) (3). In a similar way, (dien)Pt(II) forms [dienPt(1,3-DimeU-C5)](+) (4). Reactions leading to formation of 1 and 4 are slow, taking days. In contrast, Hg(CH(3)COO)(2) reacts fast with 1,3-DimeU to give (1,3-DimeU-C5)Hg(CH(3)COO) (5). Both 1-methyluracil (1-MeUH) and uridine (urdH) react with (dien)Pt(II) initially at N(3) and subsequently with either (dien)Pt(II) or Hg(CH(3)COO)(2) also at C(5) to give the diplatinated species 7 and 9 or the mixed PtHg complex 8. C(5) binding of either Pt(II) or Hg(II) is evident from coupling of uracil-H(6) with either (195)Pt or (199)Hg nuclei and (3)J values of 47-74 Hz (for Pt compounds) and 185-197 Hz (for Hg compounds). J values of Pt compounds are influenced both by the ligands trans to the uracil C(5) position and by the number of metal entities bound to a uracil ring. Both 2 and 5 were X-ray structurally characterized. 2: monoclinic system, space group P2(1)/c, a = 15.736(6) ?, b = 11.481(6) ?, c = 25.655 (10) ?, beta = 145.55(3) degrees, V = 2621.9(28) ?(3), Z = 4. 5: monoclinic system, space group P2(1)/c, a = 4.905(2) ?, b = 18.451(6) ?, c = 11.801(5) ?, beta = 94.47(3) degrees, V = 1064.77(72) ?(3), Z = 4.     

New hybrid zirconium aminophosphonates containing piperidine and bipiperidine groups

The reaction of N-(phosphonomethyl)piperidine and N,N'-bis(phosphonomethyl)bipiperidine with zirconium(IV) in hydrofluoric acid media led to the preparation of two new zirconium fluoride phosphonate derivatives with 1D and 2D structure, respectively. Their structures were solved ab initio from laboratory powder X-ray diffraction (PXRD) data. The monophosphonate derivative, with formula ZrF(2)(HF)(O(3)PCH(2)NC(5)H(10)), has a 1D structure (triclinic, space group P ?1, a = 6.6484(3) ?, b = 7.1396(3) ?, c = 12.2320(6) ?, α = 77.932(4)°, β = 87.031(6)°, γ = 78.953(5)°, V = 557.22(4) ?(3), and Z = 2) made of inorganic chains constituted from the connection of zirconium octahedra and phosphorus tetrahedra with the piperidine groups bonded on their external part. The diphosphonate derivative, with formula Zr(2)F(4)(HF)(2)(O(3)PCH(2))NC(10)H(18)N(CH(2)PO(3)), has a 2D structure (triclinic, space group P ?1, a = 6.6243(3) ?, b = 7.2472(4) ?, c = 12.2550(7) ?, α = 102.879(4)°, β = 100.29(1)°, γ = 101.287(7)°, V = 547.03(4) ?(3), and Z = 1) composed of the packing of covalent layers whose structure may be ideally obtained by the joining of adjacent chains of the 1D compound. In these hybrid layers, inorganic regions made of the connectivity of zirconium octahedra and phosphorus tetrahedra alternate with organic regions represented by the bipiperidine moieties. A section dedicated to vibrational spectroscopy analysis is also included, mainly devoted to clarify some issues not easily deducible on the basis of PXRD data and to describe the fluorine environment inside zirconium phosphonate structures.     

Chemistry of Bis(aryloxo)palladium(II) Complexes with N-Donor Ligands: Structural Features of the Palladium-to-Oxygen Bond and Formation of O-H.O Bonds

Reaction of palladium acetate with 2 equiv of sodium phenoxide in the presence of a chelate diamine ligand affords the complexes [Pd(OPh)(2)(N approximately N)] (N approximately N = bpy (1), tmeda (2), teeda (3), dpe (4), dmap (5)). These yellow to orange bis(phenoxo)palladium(II) complexes are thermally stable at room temperature in the solid state as well as in solution. Addition of an excess of pentafluorophenol to 1, 2, 4, and 5 affords crystalline complexes [Pd(OC(6)F(5))(2)(N approximately N)] (N approximately N = bpy (6), tmeda (7), dpe (8), dmap (9)). Crystals of 1 and 6 have been subjected to X-ray diffraction studies. Crystals of 1 are orthorhombic, space group P2(1)2(1)2(1) (no. 19), with a = 6.7655(6) ?, b = 16.0585(10) ?, c = 16.7275(13) ?, and Z = 4. Crystals of 6 are triclinic, space group P&onemacr; (no. 2), with a = 7.567(4) ?, b = 12.708(3) ?, c = 12.912(5) ?, alpha = 61.51(3) degrees, beta = 74.74(4) degrees, gamma = 88.78(4) degrees, and Z = 2. The molecular structures of 1 and 6 show them to be square-planar complexes, and the main structural difference between these complexes is the orientation of the aromatic rings. In 6 the OC(6)F(5) ligands are almost parallel in a face-to-face orientation (pi-pi stacking interactions), whereas in 1 the OC(6)H(5) units are skewed away from each other. An unexpected "mixed" alkoxo(aryloxo) complex [Pd(OCH(CF(3))(2))(OPh)(bpy)].HOPh (10) is formed when 1 is reacted with 1,1,1,3,3,3-hexafluoro-2-propanol. The molecular structure of 10 shows O-H.O hydrogen bonding (O.O = 2.642(8) ?) between the hydroxyl hydrogen of phenol and the oxygen atom of the phenoxide ligand as well as an additional C-H.O contact (C.O) = 2.95(1) ?), which can be regarded as the initial stage of a base-assisted beta-hydrogen elimination. Crystals of 10 are monoclinic, space group P2(1)/c, with a = 8.3241(14) ?, b = 11.0316(17) ?, c = 26.376(3) ?, alpha = 93.01(1) degrees, Z = 4. Spectroscopic data of complexes 1-10 indicate that the oxygen atom of the aryloxide or alkoxide ligand is extremely electron-rich, leading to high polarization of the palladium-to-oxygen bond. The bis(phenoxide) complexes 1, 2, and 4 associate with two molecules of phenol through O-H.O hydrogen bonds to form adducts [Pd(OPh)(2)(N approximately N)].2HOPh (N approximately N = bpy (11), tmeda (12), dpe (13)). The palladium complexes 6-9 with OC(6)F(5) groups show no tendency to form adducts with alcohols.     

Ruthenium Complexes Containing "Noninnocent" o-Benzoquinone Diimine/o-Phenylenediamide(2-) Ligands. Synthesis and Crystal Structure of the Nitrido-Bridged Complex [{LRu(o-C(6)H(4)(NH)(2))}(2)(&mgr;-N)](PF(6))(2).3CH(3)CN.C(6)H(5)CH(3)

Reaction of LRu(III)Cl(3) (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) with 1,2-phenylenediamine (opdaH(2)) in H(2)O in the presence of air affords [LRu(II)(bqdi)(OH(2))](PF(6)) (1), where (bqdi) represents the neutral ligand o-benzoquinone diimine. From an alkaline methanol/water mixture of 1 was obtained the dinuclear species [{LRu(II)(bqdi)}(2)(&mgr;-H(3)O(2))](PF(6))(3) (1a). The coordinated water molecule in 1 is labile and can be readily substituted under appropriate reaction conditions by acetonitrile, yielding [LRu(II)(bqdi)(CH(3)CN)](PF(6))(2) (2), and by iodide and azide anions, affording [LRu(II)(bqdi)I](PF(6)).0.5H(2)O (3) and [LRu(bqdi)(N(3))](PF(6)).H(2)O (4), respectively. Heating of solid 4 in vacuum at 160 degrees C generates N(2) and the dinuclear, nitrido-bridged complex [{LRu(o-C(6)H(4)(NH)(2))}(2)(&mgr;-N)](PF(6))(2) (5). Complex 5 is a mixed-valent, paramagnetic species containing one unpaired electron per dinuclear unit whereas complexes 1-4 are diamagnetic. The crystal structures of 1, 1a.3CH(3)CN, 3, 4.H(2)O, and 5.3CH(3)CN.0.5(toluene) have been determined by X-ray crystallography: 1 crystallizes in the monoclinic space group P2(1)/m, Z = 2, with a = 8.412(2) ?, b = 15.562(3) ?, c = 10.025 ?, and beta = 109.89(2) degrees; 1a.3CH(3)CN, in the monoclinic space group C2/c, Z = 4, with a = 19.858(3) ?, b = 15.483(2) ?, c = 18.192(3) ?, and beta = 95.95(2) degrees; 3, in the orthorhombic space group Pnma, Z = 4, with a = 18.399(4) ?, b = 9.287(2) ?, and c = 12.052(2) ?, 4.H(2)O, in the monoclinic space group P2(1)/c, Z = 4, with a = 8.586(1) ?, b = 15.617(3) ?, c = 16.388(5) ?, and beta = 90.84(2) degrees; and 5.3CH(3)CN.0.5(toluene), in the monoclinic space group P2(1)/c, Z = 4, with a = 15.003(3) ?, b = 16.253(3) ?, c = 21.196(4) ?, and beta = 96.78(3) degrees. The structural data indicate that in complexes 1-4 the neutral o-benzoquinone diimine ligand prevails. In contrast, in 5 this ligand has predominantly o-phenylenediamide character, which would render 5 formally a mixed-valent Ru(IV)Ru(V) species. On the other hand, the Ru-N bond lengths of the Ru-N-Ru moiety at 1.805(5) and 1.767(5) ? are significantly longer than those in other crystallographically characterized Ru(IV)=N=Ru(IV) units (1.72-1.74 ?). It appears that the C(6)H(4)(NH)(2) ligand in 5 is noninnocent and that formal oxidation state assignments to the ligands or metal centers are not possible.     

Long hydrogen-bonded rod of molecular oxide: a hexatantalate tetramer

A tetra-n-butylammonium (TBA) salt of [H(4.5)(Ta(6)O(19))](3.5-) was synthesized by reacting hydrous tantalum oxide with TBAOH. X-ray structural analysis of TBA(3.5)[H(4.5)(Ta(6)O(19))]·2THF·5.5H(2)O (THF = tetrahydrofuran) revealed that this compound consists of a hydrogen-bonded, rod-shaped tetramer of hexatantalate that is almost 30 ? long together with TBA cations and solvent molecules of crystallization [a = 20.6354(5) ?, b = 25.5951(7) ?, c = 37.2058(8) ?, α = 77.092(1)°, β = 86.177(1)°, γ = 88.683(1)°, V = 19110.9(8) ?(3), Z = 8, and space group P ?1]. (1)H NMR spectra showed that this tetrameric structure is maintained in solution.     

New vanadium selenites: centrosymmetric Ca2(VO2)2(SeO3)3(H2O)2, Sr2(VO2)2(SeO3)3, and Ba(V2O5)(SeO3), and noncentrosymmetric and polar A4(VO2)2(SeO3)4(Se2O5) (A = Sr2+ or Pb2+)

Five new vanadium selenites, Ca(2)(VO(2))(2)(SeO(3))(3)(H(2)O)(2), Sr(2)(VO(2))(2)(SeO(3))(3), Ba(V(2)O(5))(SeO(3)), Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), have been synthesized and characterized. Their crystal structures were determined by single crystal X-ray diffraction. The compounds exhibit one- or two-dimensional structures consisting of corner- and edge-shared VO(4), VO(5), VO(6), and SeO(3) polyhedra. Of the reported materials, A(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) (A = Sr(2+) or Pb(2+)) are noncentrosymmetric (NCS) and polar. Powder second-harmonic generation (SHG) measurements revealed SHG efficiencies of approximately 130 and 150 × α-SiO(2) for Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), respectively. Piezoelectric charge constants of 43 and 53 pm/V, and pyroelectric coefficients of -27 and -42 μC/m(2)·K at 70 °C were obtained for Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)) and Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), respectively. Frequency dependent polarization measurements confirmed that the materials are not ferroelectric, that is, the observed polarization cannot be reversed. In addition, the lone-pair on the Se(4+) cation may be considered as stereo-active consistent with calculations. For all of the reported materials, infrared, UV-vis, thermogravimetric, and differential thermal analysis measurements were performed. Crystal data: Ca(2)(VO(2))(2)(SeO(3))(3)(H(2)O)(2), orthorhombic, space group Pnma (No. 62), a = 7.827(4) ?, b = 16.764(5) ?, c = 9.679(5) ?, V = 1270.1(9) ?(3), and Z = 4; Sr(2)(VO(2))(2)(SeO(3))(3), monoclinic, space group P2(1)/c (No. 12), a = 14.739(13) ?, b = 9.788(8) ?, c = 8.440(7) ?, β = 96.881(11)°, V = 1208.8(18) ?(3), and Z = 4; Ba(V(2)O(5))(SeO(3)), orthorhombic, space group Pnma (No. 62), a = 13.9287(7) ?, b = 5.3787(3) ?, c = 8.9853(5) ?, V = 673.16(6) ?(3), and Z = 4; Sr(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), orthorhombic, space group Fdd2 (No. 43), a = 25.161(3) ?, b = 12.1579(15) ?, c = 12.8592(16) ?, V = 3933.7(8) ?(3), and Z = 8; Pb(4)(VO(2))(2)(SeO(3))(4)(Se(2)O(5)), orthorhombic, space group Fdd2 (No. 43), a = 25.029(2) ?, b = 12.2147(10) ?, c = 13.0154(10) ?, V = 3979.1(6) ?(3), and Z = 8.