Synthesis,structure and magnetic properties of a trinuclear cyano-bridged complex [Cu(bappz)(μ-NC)Ni(CN)2(μ-CN)Cu(bappz)](ClO4)2 {bappz=1,4-bis(3-aminopropyl)piperazine}

The bimetallic trinuclear complex [Cu(bappz)(μ-NC)Ni(CN)₂(μ-CN)Cu(bappz)](ClO₄)₂ (bappz=1,4-bis(3-aminopropyl)piperazine) has been prepared from the reaction of [Cu(bappz)](ClO₄)₂ and K₂[Ni(CN)₄] in water and its crystal and molecular structure has been determined. The structure consists of a trinuclear [Cu(bappz)(μ-NC)Ni(CN)₂(μ-CN)Cu(bappz)]²⁺ cation and two perchlorate anions. The bridging [Ni(CN)₄]²⁻ anion is coordinated by two [Cu(bappz)]²⁺ cations through two cyano groups, providing a novel trinuclear structure with the Cu–(NC)–Ni–(CN)–Cu linkage. The nickel(II) ion is four-coordinated by carbon atoms from four cyano groups (two of them, in trans position, form a bridge) in a square planar arrangement, whereas both the copper(II) ions are five-coordinated by four bappz nitrogens and one cyanide nitrogen in a distorted square–pyramidal geometry. The temperature dependence of magnetic susceptibility was measured for this compound over the range of 2–300 K. The magnetic investigation showed the presence of a very weak antiferromagnetic interaction (superexchange interaction parameter J=−0.54 cm⁻¹) between the copper atoms through the diamagnetic [Ni(CN)₄]²⁻ ion.     

Synthesis and structure of the pentanuclear mixed-metal cluster [Co4MoCp(μ3-SBut)(μ3-S)(μ3-CO)(μ-CO)2(CO)6]

The pentanuclear mixed-metal cluster [Co₄MoCp(μ₃-SBu^t)(μ₃-S)(μ₃-CO)(μ-CO)₂(CO)₆] (1) has been synthesised by reaction of [CoMoCp(CO)₇] with Bu^tSSBu^t. X-ray structural analysis identified an asymmetric unit with three cobalt atoms and one molybdenum forming an irregular tetrahedron while one cobalt–molybdenum edge is bridged by a cobalt atom. Crystal data: space group P2(1)/n, a=10.162(2), b=13.722(3), c=17.69(5) Å, β=91.44(2)°, Z=4.     

Synthesis and X-ray characterization of the quindecanuclear nickel/sulfur paramagnetic cluster [Ni15(μ3-S)6(μ4-S)9(PEt3)6]+

The quindecanuclear nickel/sulfur cluster [Ni₁₅(μ₃-S)₆(μ₄-S)₉(PEt₃)₆]⁺ has been isolated by reaction of Ni(ClO₄)₂·6H₂O with H₂S and PEt₃ in ethanol\dichloromethane solution and has been characterized by X-ray diffraction studies.     

Synthesis,characterization and weak ferromagnetic coupling in [Cu2(μ3-CO3)(SCN)2(py)4]n

The crystal structure of a novel [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n complex has been determined. It comprises of [CuCO₃Cu]_n infinite chains, running along the a-axis, and is in this aspect similar to the previously described [Cu(CO₃)(4-aminopyridine)₂]·H₂O complex. The FTIR spectrum of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n has been recorded and analyzed. A CuCO₃Cu intrachain coupling between Cu(II) atoms has been found to be responsible for the weak ferromagnetic properties of [Cu₂(μ₃-CO₃)(SCN)₂(py)₄]_n.     

Synthesis and crystal structure of [Ni{bis(2,5-dihydroxysalicylidene)ethylenediaminato}]: a hydrogen bonded assembly of Ni(II)–salen complex

The hydrogen bonded assembly of salen type complexes was studied. The nickel(II) complex with N,N^′-bis(2,5-dihydroxysalicylidene)ethylenediaminato was synthesized, and structurally characterized. The compound has two hydroxy groups at the both terminals of the tetradentate ligand. One of the two hydroxy groups of the nickel(II) complex forms a hydrogen bond with a coordinating oxygen donor of the adjacent molecule to yield a hydrogen bonded one-dimensional chain. These chains are also associated by π–π interactions with interlocking fashion to produce a two-dimensional structure. The guest ethanol molecules are incorporated between the two-dimensional layers.     

Crystal structure and catalytic studies of heterodinuclear complex [CuZn(μ-OAc)(μ-OH)(μ-OH2)(bpy)2](ClO4)2

The heterodinuclear copper–zinc complex [CuZn(μ-OAc)(μ-OH)(μ-OH₂)(bpy)₂](ClO₄)₂ has been synthesized from solid state reaction and its crystal structure was established. The heterobimetallic complex is quite efficient catalyst for hydrogen peroxide mediated oxidation of alcohols into corresponding carbonyl compounds.     

Electrical conductance and apparent molar volumes of Al(ClO4)3, Be(ClO4)2, and Cu(ClO4)2 in N,N-dimethylacetamide solutions at 25°C

Equivalent conductances and apparent molar volumes of Al(ClO₄)₃, Be(ClO₄)₂, and Cu(ClO₄)₂ in N,N-dimethylacetamide at 25°C are reported. The limiting equivalent conductances, the first step association constants, and the apparent molar volumes at infinite dilution are derived and discussed in terms of influence of nature of cation on the properties of DMA-solvated cations.     

Tricarbonyl rhenium complex of 2,2′-bis(4,5-dimethylimidazole) — Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

The paper presents a combined experimental and computational study of the tricarbonyl rhenium(I) complex incorporating 2,2′-bis(4,5-dimethylimidazole) (tmbiimH₂). The complex has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of [Re(CO)₃(tmbiimH₂)Cl] has been calculated with the density functional theory (DFT) method, and the electronic spectrum of the complex was investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ.     

Preparation of a new cobalt-containing diphosphine ligand and its reaction towards dicobalt octacarbonyl; X-ray crystal structure of [Co2(CO)4(μ-CO)2{μ-P,P-(μ-PPh2CCPPh2)Co2(CO)6}]

Consecutive reactions of bis(diphenylphosphino)acetylene with Co₂(CO)₈ resulted in an alkyne-bridged, diphosphine-chelated tetracobalt complex, [Co₂(CO)₄(μ-CO)₂{μ-P,P-(μ-PPh₂CCPPh₂)Co₂(CO)₆}] (2), which has been characterized by spectroscopic means as well as X-ray studies.     

Synthesis and structure of a supramolecular octanuclear Cu(II) complex {[Cu(sae)]42CH3OH·H2O}2 through both μ-oxo and hydrogen bonds (sae = 2-salicylideneamino-1-ethanol)

A new supramolecular octanuclear copper(II) complex, {[Cu(sae)]₄2CH₃OH·H₂O}₂, has been synthesized and structurally characterized. The structure of the complex consists of two tetracopper(II) cubane units related by hydrogen bonds.     

Syntheses and X-ray crystal structures of [Zn(cyclen)–im–Zn(cyclen)](ClO4)3 and [Ni(cyclen)(imH)(ClO4)](ClO4) (cyclen=1,4,7,10-tetraazacyclododecane,im=imidazolate)

The imidazolate-bridged binuclear zinc(II) macrocyclic complex, [Zn(cyclen)–im–Zn(cyclen)](ClO₄)₃ (1) and the free imidazole coordinated mononuclear nickel(II) complex, [Ni(cyclen)(imH)(ClO₄)](ClO₄) (2) (cyclen=1,4,7,10-tetraazacyclododecane, im=imidazolate) have been synthesized. Complexes 1 and 2 have been characterized by single crystal structural analyses. In complex 1 both zinc(II) ions are five-coordinated with a distorted square pyramidal geometry composed of four nitrogen atoms from cyclen and one nitrogen atom from the bridging imidazolate ion with N₅ chromophore. Complex 2 is mononuclear nickel(II) having six-coordination with distorted octahedral geometry consisting of four nitrogen atoms from cyclen, one nitrogen atom from the imidazole molecule and one oxygen from one of the perchlorate ions to give a N₅O chromophore.     

Tricarbonyl rhenium complex of 2,6-bis(8′-quinolinyl)pyridine: Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

2,6-Bis(8′-quinolinyl)pyridine (bqp) reacts with pentacarbonyl rhenium chloride in toluene to give fac,fac-[Re(bqp-κ³N)(CO)₃](Cl). X-ray crystallographic data on fac,fac-[Re(bqp-κ³N)(CO)₃](Cl) show that the bqp ligand and carbonyl ligands achieve a mutually facial arrangement. A mix of MLCT and π–π* ligand centered transitions is observed for the low energy UV–vis absorption bands. The complex is emissive in solution and appears to be dominated by a MLCT-based process. Electronic and structural characteristics are supported by DFT calculations.     

A novel 3D coordination polymer [Cd15(μ4-Mtta)12(μ3-Mtta)6(μ3-SO4)4(μ3-OH)4]: Synthesis,structure and solid properties

A 3D coordination polymer, {[Cd₁₅(μ₄-Mtta)₁₂(μ₃-Mtta)₆(μ₃-SO₄)₄(μ₃-OH)₄] · 6H₂O}_n (1) (Mtta = 5-methyl-tetrazolate), which shows the rare multifunction of in situ formed Mtta and bright photo-induced blue emission, was isolated from a hydrothermal reaction of CdSO₄ · 8/3H₂O, NaN₃ in acetonitrile and water.     

Unexpected fragmentation of the Fe3(CO)9(μ3-Se)(μ3-AsCH3) cluster core in the reaction with CpCo(CO)2: synthesis and structure of Fe3(CO)6(μ3-Se)(μ-AsCH3{CpFe(CO)2})2(μ-CO)

The [Fe₃(CO)₆(μ₃-Se)(μ-AsCH₃{CpFe(CO)₂})₂(μ-CO)] (Cp=η⁵-C₅H₅) cluster has been obtained by the reaction of [Fe₃(CO)₉(μ₃-Se)(μ₃-AsCH₃)] with [CpCo(CO)₂]. Its crystal and molecular structures have been determined by X-ray analysis.     

Ru4(μ-CO)(CO)9(η4-μ4-C6H4)(η2-μ1,μ4-PPhCH2CH2PPh2): an unusual pyrolysis product of Ru3(CO)10(dppe) containing a benzyne ligand

The thermal decomposition of Ru₃(CO)₁₀(dppe) in refluxing benzene gives, in contrast to the pyrolysis of the dppm analogue, the tetranuclear cluster Ru₄(μ-CO)(CO)₉(η⁴-μ₄-C₆H₄)(η²-μ₁,μ₄-PCH₂CH₂PPh₂) (1) along with Ru₃(CO)₉(η²-μ₁,μ₂-C₆H₅)(η³-μ₁,μ₂-PPhCH₂CH₂PPh₂) (2). The single-crystal structure analysis of 1 reveals a square-planar tetraruthenium skeleton containing a η⁴-μ₄-benzyne ligand as well as a η²-μ₁,μ₄-phosphinidene–phosphine ligand.     

Synthesis,structure and properties of a new copper (II) complex, [Cu2(4,4′-bpy)5(H2O)4](ClO4)4(4,4′-bpy)(DMF)2(H2O)2

A new copper (II) complex with formula [Cu₂(4,4′-bpy)₅(H₂O)₄](ClO₄)₄(4,4′-bpy)(DMF)₂(H₂O)₂ has been synthesized by reaction of 4,4′-bpyridine (4,4′-bpy) with Cu(ClO₄)₂. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as C–H?O bonds, anion?π and C–H?π interactions are also evident in the structure. The preliminary investigation on the thermal property of the complex is presented.     

Synthesis,structure and reactions of triply selenolate-bridged diiron complex [Cp*Fe(μ-SeMe)3FeCp*]

Two new iron–selenolate complexes [Cp*Fe(μ-SeMe)₃FeCp*] (Cp* = η⁵-C₅Me₅) (1) and [Cp*Fe(μ-SeMe)₃FeCp*][FeCl₃] (2) were prepared by the oxidative addition reaction of MeSeSeMe with [Cp*FeCl]₂ in 25% and 20% yields, respectively. In refluxing toluene, the methyl groups in the selenolate ligands of complex 1 were removed, affording a cubane cluster [Cp*₄Fe₄Se₄] (3) in 50% yield. Complex 1 was oxidized by HBF₄ to give [Cp*Fe(μ-SeMe)₃FeCp*][BF₄] (4), and the reverse reduction reaction occurred in the presence of CoCp₂.