Theoretical Studies on A3H3+ (A = C, Si, Ge) as π Ligands in Organometallic Chemistry
journal contributionposted on 02.11.2001, 00:00 by Gantasala N. Srinivas, Liwen Yu, M. Schwartz
η3 π complexes of A3H3+ (A = C, Si, Ge) with the organometallic fragments Co(CO)3, Rh(CO)3, Ir(CO)3, Ni(CO)3, Co(PH3)3, and Ni(PH3)3 have been studied at the B3LYP and B3P86 levels using the 6-31G(d) basis on ligands and SBKJC-21G relativistic effective core potential and their associated basis sets on metals. All the π complexes are minima. In Si and Ge complexes there is a ligand to metal charge transfer, making Si3H3 and Ge3H3 cationic ligands, whereas in C complexes there is a small charge transfer from metal to ligand, making C3H3 ligands anionic. These remarkable differences in electronic structure between carbon and its heavier analogues are explained using molecular orbitals and natural charges. All the π complexes for Si and Ge are considered viable targets for synthetic pursuit.