Transition‐Metal Complexes [(PMe3)2Cl2M(E)] and [(PMe3)2(CO)2M(E)] with Naked Group 14 Atoms (E=C–Sn) as Ligands; Part 1: Parent Compounds

The equilibrium geometries and bond dissociation energies of 16‐valence‐electron(VE) complexes [(PMe₃)₂Cl₂M(E)] and 18‐VE complexes [(PMe₃)₂(CO)₂M(E)] with M=Fe, Ru, Os and E=C, Si, Ge, Sn were calculated by using density functional theory at the BP86/TZ2P level. The nature of the M? E bond was analyzed with the NBO charge decomposition analysis and the EDA energy‐decomposition analysis. The theoretical results predict that the heavier Group 14 complexes [(PMe₃)₂Cl₂M(E)] and [(PMe₃)₂(CO)₂M(E)] with E=Si, Ge, Sn have C_2v equilibrium geometries in which the PMe₃ ligands are in the axial positions. The complexes have strong M? E bonds which are slightly stronger in the 16‐VE species 1ME than in the 18‐VE complexes 2ME . The calculated bond dissociation energies show that the M? E bonds become weaker in both series in the order C>Si>Ge>Sn; the bond strength increases in the order Fe