The coordination of [(η-Cp)2Pb] and [(η-Cp)2Sn] by bidentate Lewis-base ligands gives the first examples of adducts of neutral p-block metallocenes. Ab initio MO calculations of [(η-Cp)2Pb·TMEDA] (1) (TMEDA = (Me2NCH2)2), [Cp2Pb·4,4′-Me2bipy] (2) (4,4′-Me2bipy = 4,4′-dimethylbipyridine), and the new complex [(η-Cp)2Sn·TMEDA] (3) confirm that despite the presence of longer Pb-N and Sn-N bonds in the solid-state structures of the TMEDA adducts, the association of TMEDA with the metallocenes is more favorable than with 4,4′-Me2bipy. This finding is a consequence of the greater reorganization energy of 4,4′-Me2bipy compared to TMEDA. The low association energies of these species can be rationalized in terms of metal lone pair/ligand lone pair repulsion.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry