COBALT(III) ALKYL COMPLEXES OF 1,2-BIS(2-PYRIDINECARBOXAMIDO)-BENZENE (H2BPB) AND 4,5-DICHLORO-1,2-BIS(2-PYRIDINECARBOX-AMIDO)BENZENE (H2BPC) AND X-RAY CRYSTAL-STRUCTURES OF [CO(BPC)(CH2CH2CME=CH2)(H2O)] AND [CO(BPB)ET(H2O)]

A series of organo and non-organo cobalt complexes of bpb and bpc ligands [H2bpb = 1,2-bis(2-pyridinecarboxamido)benzene, H2bpc = 4,5-dichloro-1,2-bis(2-pyridinecarboxamido)benzene] have been synthesised. Complexes prepared include Na[CoL(CN)2], Na[CoL(N3)2], [CoL(py)2]ClO4 and [CoL(R) (H2O)] (L = bpb or bpc; py = pyridine; R = Me, Et, Pr(i) or CH2CH2CMe = CH2). The complex [CoL(CH2CH2CMe = CH2) (H2O)] was formed as a rearrangement product from the reaction of 3,3-dimethylallyl bromide and [CoL].H2O in the presence of NaBH4 and NaOH in methanol. The complexes [Co(bpc) (CH2CH2CMe = CH2) (H2O)] 1 and [Co(bpb)Et(H2O)] 2 have been characterized by X-ray crystallography: 1, space group Pnma, a = 13.934(2), b = 12.204(2), c = 13.173(2) angstrom, Z = 4, and R = 0.046 for 1129 observed reflections; 2, space group Pnma, a = 15.072(1), b = 12.119(2), c = 9.884(3) angstrom, Z = 4, and R = 0.034 for 1387 observed reflections. Electrochemical studies on the one-electron oxidation of these complexes suggest the involvement of the equatorial ligand in these processes.