Preparation and Spectroscopic Studies of (Diethylenetriamine)cobalt(III) Complexes with l -Penicillaminate or Its Derivative

The (diethylenetriamine)(l-penicillaminato)cobalt(III) complex, [Co(l-pen)(dien)]+, was chromatographically separated into three isomers, trans(NiN), trans(NiO) and trans(NiS). Each of these gave a corresponding isomer of the (diethylenetriamine)(S-methyl-l-penicillaminato)cobalt(III) complex, [Co(l-smp)(dien)]2+, by the reaction with dimethyl sulfate. The (triammine)(S-methyl-l-penicillaminato)cobalt(III) complex was also derived from the corresponding l-pen complex, [Co(l-pen)(NH3)3]+. The absorption and CD spectra of the l-pen complexes were compared with those of the l-smp ones to specify the geometrical configurations. The l-pen complexes exhibited characteristic absorption behavior and CD spectra in the region of (14–30)×103 cm−1.