Uche B. Eke

Bis(acetonitrile-κN)dichlorido(η4-cyclo­octa-1,5-diene)ruthenium(II) acetonitrile monosolvate

In the title RuII complex, [RuCl2(C8H12)(C2H3N)2]·CH3CN, the metal ion is coordinated to the centers of each of the double bonds of the cyclooctadiene ligand, to two chloride ions (in cis positions) and to two N-atom donors (from MeCN molecules) that complete the coordination sphere for the neutral complex. The coordination about the RuII atom can thus be considered to be octahedral with a slightly trigonal distortion. There is also one acetonitrile solvent molecule per molecule which is outside the coordination sphere of the ruthenium atom.

Spectral studies of transition metal complexes of dihydrobis(1-pyrazoyl)borate with some Lewis bases

Abstract Co(II), Ni(II) and Cu(II) complexes of dihydrobis(1-pyrazolyl)borate and their adducts with some Lewis bases have been prepared and characterized by elemental analyses, IR and UV–vis spectroscopic techniques. The adducts were either 1:1 or 1:2 complexes depending on whether the Lewis base was bidentate or monodentate. The results indicate that adducts with 1,10-phenanthroline were the most stable due to the chelating effect of the Lewis base. The order of reactivity of the complexes was determined to be Ni(H2BPz2)2 > Cu(H2BPz2)2 > CoH2(BPz2)2 > Co(H2BPz2)2. The effects of various solvents (i.e., benzene, chloroform and DMF) on the structure were studied. The solvents appear to minimally affect the visible spectra of Co(H2BPz2)2. The Ni(H2BPz2)2 and Cu(H2BPz2)2 adducts exhibit a four-coordinate structure in non-coordinating solvents. However, in coordinating solvents, such as DMF, the adducts exhibit six-coordinate structures.

Synthesis of new ruthenium(II) complexes derived from labile nitrile ligands: an alternative route to the preparation of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II)

Abstract New ruthenium(II) complexes containing labile nitrile ligands have been prepared by treatment of either the polymer [{RuCl2(COD)}x] (COD = cycloocta-1,5-diene) (1) or its derivative [RuCl2(COD)(NCCH3)2]·NCCH3 (2) with the appropriate nitrile ligands in refluxing acetonitrile under argon. A new route to synthesis of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II) (7) was also reported. A redetermination of the structure of 7 was undertaken and X-ray crystallographic data revealed that the complex crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.7016(9) Å, b = 13.0847(10) Å, c = 14.1498(10) Å, α = 101.46(3)°, V = 2080.6(3) Å3, Z = 2 and R = 0.0309. Its polymorph 7′ was also obtained. The crystal structure of 4 was also determined. This complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.0510(3) Å, b = 11.0984(13) Å, c = 13.0450(16) Å, α = 90°, V = 3886.5(8) Å3, Z = 8 and R = 0.0282.