DFT calculations of the molecular structures and vibrational spectra of dimethylzinc and dimethylcadmium complexes with bidentate nitrogen ligands

The structures and vibrational spectra of dimethylzinc and dimethylcadmium complexes with o-phenanthroline (PHEN), 2,2'-bipyridine (BIPY), and tetramethylethylenediamine (TMED) have been calculated by DFT methods. The unexpected deviations in the dihedral angles between the plane of the o-phenanthroline ligand and the planes of the dimethyl-metal groups are due to low wavenumber twisting vibrations and the previously unknown locations of the metal-nitrogen stretching motions have been established. The results indicate that the ligands are not strongly bound, suggesting that the complexes may indeed be useful nontoxic precursors to Me2Zn and Me2Cd for use in the electronics industry.