Binuclear Cobalt(II) Complexes with Biladiene-a,c in DMF

The reaction of cobalt(II) acetate with alkylbiladiene-a,c (H2L) in DMF at 298.15 K was studied by spectrophotometry. The resulting binuclear complexes Co2L(AcO)2 and Co2L2 contain one or two coordinated biladiene-a,c ligands, depending on the ratio of the reagent concentrations. The compositions of the complexes were determined and the thermodynamic constants of their formation were calculated from spectrophotometric data with the use of the molar ratio method. It was assumed that the high thermodynamic stabilities of heteroligand binuclear complexes M2L(AcO)2 are responsible for the formation of double-stranded biladiene complexes M2L2.