H-bridged A3H3+ (A = Si and Ge): A π-ligand in organometallic chemistry

Abstract

Organometallic complexes based on H-bridged Si₃H₃⁺ and Ge₃H₃⁺ ligands were studied at the B3LYP and B3P86 levels. Relativistic effective core potentials (SBKJC-21G and Stuttgart-RSC) and their associated basis sets were used on metals and the 6-31G(d) basis set was used on ligands. All the complexes (A₃H₃)Co(CO)₃ (9, C_3v), (A₃H₃)Rh(CO)₃ (10, C_3v) and (A₃H₃)Ir(CO)₃ (11, C_3v) (A = Si and Ge) are minima and more stable than the complexes based on Si₃H₃⁺ and Ge₃H₃⁺ ligands with terminal hydrogens (9a–11a). The stability of the bridged systems increases from Si to Ge. Isolobal and isosynaptic analogies connect these complexes with other organometallic complexes (e.g. (μ-H)₃Fe₃(CO)₉(μ₃-CMe)) and main group pyramidal systems (e.g. (μ-H)₃B₃H₃(μ₃-CH)).