X-ray study of the molecular structure of α-mercury and α-platinummercury derivatives of l-menthyl phenylacetate

The molecular structures of the L-menthyl ester of S-α-bromomercuriphenyl-acetic acid, diastereomer II, α]²⁰_D ?18°, and of the related L-menthyl ester of α-bromobis(triphenylphosphine)platinummeruriphenylacetic acid, VI, have been investigated by the X-ray method. Insertion of L₂Pt carbenoid appears to occur into the HgBr bond in II and two phosphine ligands in the product VI occupy cis positions in a planar square around the platinum atom. The HgPt distance is 2.50 Å; there is intermolecular HgBr coordination in II, the distance being 3.23 Å.