Search

Two new tetrahedral tungsten cyanide cluster compounds, [Cu(dien)]3[W4Te4(CN)12] · 9H2O (1) (dien=diethylenetriamine) and [Ni(en)(NH3)]3[W4Se4(CN)12] · 7.5H2O (2) (en=ethylenediamine), were synthesized by treating aqueous solutions of the saltlike cluster compound K6[W4Te4(CN)12] · 5H2O/K6[W4Se4(CN)12] · 6H2O with copper(II)/nickel(II) chloride in aqueous ammonia containing dien/en. The cyano-bridged layered coordination polymeric compounds were characterized by single-crystal X-ray diffraction analysis: monoclinic, space group P21 for 1; trigonal, space group R&3macr; for 2. Structures of 1 and 2 consist of infinite neutral layers of cluster components {W4Te4(CN)12}/{W4Se4(CN)12} connected, one another by {Cu(dien)} or {Ni(en)(NH3)} fragments, respectively. [Copyright &y& Elsevier]

Abstract: New complexes of triangular clusters M3S4 4+ (M=Mo, W) with incomplete cuboidal metal–chalcogenide framework bearing chiral α-hydroxy and amino acids have been prepared. l-lactic acid (H2lac), l-mandelic acid (H2man), and l-alanine (Hala) react with [W3S4Br4(PPh3)3] in 1:1 ratio to yield, respectively, monosubstituted complexes [W3S4(PPh3)3Br3(Hlac)(CH3CN)] (1), [W3S4(PPh3)3Br3(Hman)(CH3CN)] (2), and [W3S4(PPh3)3Br3(Hala)(CH3CN)]Br (3). In the presence of base [Mo3S4Cl4(PPh3)3] gives trisubstituted complexes [Mo3S4(PPh3)3(Hlac)2(lac)] (4) and [Mo3S4(PPh3)3(Hman)3]Cl (5). Circular dichroism studies of 4 indicate chirality transfer from the ligand to the Mo3S4 4+ cluster core. These complexes incorporate Cu+ with the formation of corresponding {M3CuS4}5+ cuboidal derivatives. NMR and ESI-MS studies of solution behavior are presented. [Copyright &y& Elsevier]

Abstract: New metal–organic coordination polymer, (Me3NH)[Fe3(μ3-O)(μ-HCOO)8]·DMF (1), was synthesized by heating of Fe(NO3)3·9H2O and [NH(CH3)3]Cl in DMF/HCOOH solution. The single-crystal X-ray structure analysis reveals this compound has 1D anionic framework structure built from Fe3O(μ-HCOO)6 cluster units linked by formate bridges. Compound 1 was characterized by elemental analysis, IR and TGA. The magnetic susceptibility measurements indicate a strong antiferromagnetic exchange interaction between FeIII ions in the cluster and intercluster magnetic interaction. [ABSTRACT FROM AUTHOR]

Abstract: A series of copper(II) complexes, i.e. Cu2LCl4, CuLCl2·H2O and [Cu2L2Cl4]·2MeCN (8), based on a new potentially polytopic ligand, 3,5-bis(4,6-dimethylpyrimidin-2-yl)-4H-1,2,4-triazol-4-amine (3b, L), have been synthesized. The crystal structures of L and [Cu2L2Cl4]·2MeCN were studied by X-ray single crystal analysis. The dinuclear compound [Cu2L2Cl4]·2MeCN represents the first example of structurally characterized metal complexes with 3,5-di(pyrimidin-2-yl)-4H-1,2,4-triazol-4-amines. Both copper atoms have distorted tetragonal–pyramidal 3N+2Cl environment. Surprisingly, in contrast to the complexes based on 3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-amine (pyridinyl analog of L), the compound [Cu2L2Cl4]·2MeCN adopts a dinuclear trans-(N′,N1 ,N2 )2 double bridging binding mode which is due to tridentate coordination of two L molecules linking two copper atoms through N1 ,N2 -triazole and N′-pyrimidine atoms. It seems to be reasonable that it is methyl groups in pyrimidinyl moiety that obstruct the expected dinuclear (N′,N1 ,N2 ,N″)2 double bridging coordination being one of the most common for 4-substituted 3,5-di(pyridin-2-yl)-4H-1,2,4-triazoles and 3,5-di(pyridin-2-yl)-1,2,4-triazolates. Due to π–π stacking interactions, molecules of Cu2L2Cl4 in the structure of [Cu2L2Cl4]·2MeCN form 1D chains. [ABSTRACT FROM AUTHOR]

Abstract: Reaction of [Mo2O2(μ-S)2(H2O)6]2+ with Mo(CO)6 or metallic Mo under hydrothermal conditions (140°C, 4M HCl) gives oxido-sulfido cluster aqua complex [Mo3(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (1). Similarly, [W3(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (2) is obtained from [W2O2(μ-S)2(H2O)6]2+ and W(CO)6. While reaction of [Mo2O2(μ-S)2(H2O)6]2+ with W(CO)6 mainly proceeds as simple reduction to give 1, [W2O2(μ-S)2(H2O)6]2+ with Mo(CO)6 produces new mixed-metal cluster [W2Mo(μ3-S)(μ-O)2(μ-S)(H2O)9]4+ (3) as main product. From solutions of 1 in HCl supramolecular adduct with cucurbit[6]uril (CB[6]) {[Mo3O2S2(H2O)6Cl3]2CB[6]}Cl2⋅18H2O (4) was isolated and structurally characterized. The aqua complexes were converted into acetylacetonates [M3O2S2(acac)3(py)3]PF6 (M3 =Mo3, W3, W2Mo; 5a–c), which were characterized by X-ray single crystal analysis, electrospray ionization mass spectrometry and 1H NMR spectroscopy. Crystal structure of (H5O2)(Me4N)4[W3(μ3-S)(μ2-S)(μ2-O)2(NCS)9] (6), obtained from 2, is also reported. [ABSTRACT FROM AUTHOR]

Dark-brown single crystals of the title compound 1 were obtained in high yield by layering a CuCl2 solution in 25% aqueous ammonia on a glycerol solution of K6[W4Te4(CN)12]·5H2O. The complex 1 was characterized by single crystal X-ray diffraction analysis and IR spectroscopy. The X-ray structure of 1 reveals a polymeric chain cyano-bridged cluster-metal coordination compound. The [W4Te4(CN)12]6− cluster anions are linked one to another by Cu2+ cations through coordination by nitrogen atoms of the CN groups. [Copyright &y& Elsevier]

From solutions of seleno bridged triangular cluster Mo3Se4(aq)4+ in HCl, crystalline adducts with cucurbituril (Cuc, C36H36N24O12) of different composition, depending on HCl concentration, were isolated. From 2 M HCl, a monosubstituted cationic cluster crystallizes as {[Mo3Se4Cl(H2O)8]2(C36H36N24O12)}Cl6·16H2O (1). Increase in HCl concentration to 6 M gives a pentasubstituted anionic species, (H3O)2[Mo3Se4Cl5(H2O)4]2(C36H36N24O12)·15H2O (2). The crystal structures of 1 and 2 were determined by X-ray crystallography. Each portal of Cuc in 1 is covered with cluster cations [Mo3Se4Cl(H2O)8]3+ like a ‘lid’ on a ‘barrel’. Six water molecules in the trans position to the core μ2-Se form complementary hydrogen bonds with oxygen atoms of Cuc (O⋯O, 2.713–3.067 A˚). In 2 the complementarity is lost and the main structure building factor is short Se⋯Se interactions (Se⋯Se, 2.96–3.43 A˚) between two adjacent anionic clusters. Stereochemistry of halide substitution in the triangular clusters M3Q4 is analyzed. [Copyright &y& Elsevier]