G. M. Golzar Hossain

Structural studies of Ni(II), Zn(II) and Cd(II) complexes with saccharinate and 2,2′-bipyridine ligands

Abstract The syntheses and properties of the Ni(II) complex [Ni(sac)(bipy)2(H2O)]·sac (3) (sacH=saccharin, bipy=2,2′-bipyridine) and crystal structural studies of 3 and two other related derivatives [Zn(sac)(bipy)2(H2O)]·sac (5) and [Cd(sac)2(bipy)2] 6 are described. The Ni and Zn complexes belong to an isostructural series along with the corresponding Mn (1) and Co (2) compounds. These compounds have six coordinate octahedral structures with two mutually cis bipy, one sac− ion and the aqua ligands in the coordination sphere, and one uncoordinated sac− ion hydrogen bonded to the aqua ligand, and provide examples of ‘cation–anion pair’ formation. The Cd complex is also six coordinate octahedral, but in this case the two chelating bipy ligands are mutually trans, and both the sac− anions are directly bonded with the metal. The variations of the coordination geometry parameters in the complexes are compared and discussed.

Two novel Zn(II) helical chain polymers containing both bridging and terminal carboxylato groups

Abstract Two novel carboxylato-bridged Zn(II) polymeric complexes [Zn(L)(CCl3COO)]n and [Zn(L)(CF3COO)]n, where [L=2-N-(2′-pyridylimine)benzoic acid] have been synthesized and structurally characterized. The structures of the two complexes are similar with the Zn(L)(Cl3CCO2) or Zn(L)(F3CCO2) units being repeated to form infinite helical chains. In each structure, the neighbouring Zn atoms are bridged sequentially by syn–anti carboxylate groups of the Schiff base.

The rational synthesis of tetranuclear heterometallic butterfly clusters: reactions of [M2(CO)6(μ-pyS)2] (M = Re, Mn) with group VIII metal carbonyls

Heating [Os3(CO)10(NCMe)2] with [M2(CO)6(μ-pyS)2] (M = Re, Mn) (1–2) in benzene affords tetranuclear mixed-metal butterfly clusters [MOs3(CO)13(μ3-pyS)] (3–4). Similar reactions with Ru3(CO)12 give [MRu3(CO)13(μ3-pyS)] (5–6); however, when the latter is carried out in toluene the tetraruthenium sulfido cluster [Ru4(CO)12(μ-py)2(μ4-S)] (7) is the major product. Treatment of Fe3(CO)12 with 1 in refluxing toluene affords the mixed-metal sulfido cluster, [Fe2Re2(CO)13(μ-py)(μ-pyS)(μ4-S)] (8), while a similar reaction with 2 furnishes the tetrairon cluster [Fe4(CO)12(μ-py)2(μ4-S)] (9). Addition of PPh3 to 3 in the presence of Me3NO affords both the mono- and bis(phosphine)-substituted products [ReOs3(CO)12(PPh3)(μ3-pyS)] (10) and [ReOs3(CO)11(PPh3)2(μ3-pyS)] (11), respectively. All new complexes have been characterized by a combination of spectroscopic data and single-crystal X-ray diffraction studies.

Reaction between [Ru3(CO)10(μ-dppm)] (dppm = Ph2PCH2PPh2) and Te2(C6H4OEt-4)2: X-ray crystal structure of [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}]

Treatment of [Ru3(CO)10(μ-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene afforded the new aryltellurol bridged complex [Ru2(CO)4(μ-TeC6H4OEt-4)2 (μ-dppm)] (2) together with three known complexes [Ru4(CO)8(μ-CO)(μ4-Te)2(μ-dppm)] (3), [Ru2(CO)6{μ-CH2PPh(C6H4)PPh}] (4), and [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P21/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, β = 97.49(2)°, V = 2560.4(8) Å3, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C6H4PPh(CH2)PPh which is attached to one Ru by the C6H4 group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.

X-ray structure of [(μ-H)Os3(CO)10(μ-1,8-η2-C9H6N)]

AbstractDecacarbonyl-μ-hydrido-μ-1,8-η2-quinoline-triosmium crystallizes in the triclinic space group P

A new cyano-bridged Ca(II)–Fe(III) complex containing both molecular square and linear trimetallic species

\bar 1

Bis{3-amino-1-carbamo­thioyl-5-[(2-{[(5-methyl-1H-imidazol-3-ium-4-yl)meth­yl]sulfan­yl}eth­yl)amino]-1H-1,2,4-triazol-4-ium} hexa­chloridobismuthate(III) nitrate dihydrate

with a = 7.8551(6), b = 9.1283(8), c = 16.7915(8) Å, α = 74.788(2), β = 88.086(2), γ = 66.392(3)°, V = 1062.22(13)° Å3, T = 150 K, and Z = 2. The molecule consists of an Os3 triangle with the hydride and the heterocyclic ligand bridging the same Os—Os edge. The heterocyclic ligand is coordinated through the C(8) carbon and nitrogen atoms in a new μ-1,8-η2-bonding mode. The Os—Os distances lie in the close range 2.8837(4)–2.9034(4) Å with an average value of 2.892(7) Å.

cis-Bis[4-amino-N-(pyrimidin-2-yl)benzene­sulfonamido-κ2 N,N′]bis­(dimethyl sulfoxide-κO)cadmium

The molecule of the title compound, [Cu4I4(C18H21P)4], which lies on a crystallographic twofold rotation axis, displays a cubane-like Cu4I4 core.