Which of the following complexes exhibits optical isomerism due to the absence of a plane of symmetry and a center of inversion in its molecular geometry?

💡 Solution & Explanation

Optical isomerism in coordination compounds requires the complex to be chiral and non-superimposable on its mirror image. The cis isomer of dichlorobis(ethylenediamine)cobalt(III) lacks both a plane of symmetry and a center of inversion, existing as optically active dextro and laevo enantiomers, whereas the trans isomer possesses a plane of symmetry and is optically inactive. Enantiomers rotate plane-polarized light in opposite directions.