A (phenylenediselenolato)cobalt complex dimer, [Co(η5-C5H5) (Se2C6H4)]2 (1), was synthesized by a reaction of carbonyl(η5-cyclopentadienyl)diiodocobalt(III) ([Co(η5-C5H5)I2(CO)]) with poly(o-diselenobenzene). The structure of 1, determined by single-crystal X-ray crystallography, was found to be located in the space group of P21/c (No. 14), with a = 9.3346(5) Å, b = 11.6477(9) Å, c = 10.2179(5) Å, β = 111.491(1)°, and Z = 2. Covalent Co-Se bonds bridge the metal centers. In solution, dimers and monomers coexist at equilibrium. The dissociation equilibrium constant of 1 in solution was evaluated by 1H NMR spectra at several temperatures between 20 and 80 °C. Dissociation enthalpies/entropies were found to be 50/110, 60/120, and 88 kJ mol-1/200 J K-1 mol-1 in dimethyl sulfoxide-d6, benzene-d6, and chloroform-d1, respectively.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry