Circular Dichroism Spectra of Some Transition Metal Complexes with (1R,2R)-1,2-Cyclopentanediamine

Bischelates, three isomers of dicyanocobalt(III), trans-dichlorocobalt(III), and copper(II), and a monochelate, tetracyanoferrate(II), of the title diamine were prepared, and their CD spectra were reported. Major positive components were found for Ia bands, as was to be expected for the preferred λ conformation, but minor positive components were observed for the Ib band with the trans-dianionocobalt(III) complexes. The configurational and the vicinal effects, as calculated from the CD spectra of the cis-dicyanocobalt(III) complexes, are shown to be different from those of (1R,2R)-1,2-cyclohexanediamine. The CD spectra of the Fe(II) and Cu(II) complexes are consistent with the conformational effect of the title diamine.