I'm a medical practitioner but sometimes I find time to discuss few topics of chemistry with my son who has just passed out his 12th standard exams. Regarding optical isomerism I have learned that a chiral center is an essential requirement as is there in "Lactic Acid" {CH4-CH(OH)-COOH}. But in co-ordinate compounds like "bis(glycinato)Nickle(II)" I find same ligand (glycinato) bound on either side of a tetrahedral Nickle with two atoms each of Oxygen & Nitrogen occupying the four corners of tetrahedron. Then where is the chiral center?

  • $\begingroup$ The decisive factor is if the mirror image of the complex is or is not identical to original. E.g. meso-tartaric acid has 2 chiral centers that mutually cancel, the molecule has plane of symmetry and mirrored images are identical, so not optically active. $\endgroup$
    – Poutnik
    Jul 29, 2022 at 5:22
  • $\begingroup$ There are octahedral derivatives of this compound (and they can be chiral as all bis(bidentate-ligand) octahedral complexes are. If it really is tetrahedral, it won't be chiral. $\endgroup$
    – matt_black
    Jul 29, 2022 at 9:27
  • $\begingroup$ This question/answer is somewhat related. $\endgroup$ Jul 30, 2022 at 16:41


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