Structures and electronic states of gallium–acetone complexes: ab-initio DFT study

The structures and electronic states of acetone–metal complexes (Ac–M, where M=Ga, Al, and B) have been calculated by means of ab-initio DFT and configuration interaction (CI) calculations in order to shed light on the mechanism of the electron conductivity and doping effects. It was found that the electronic states of Ac–Ga and Ac–Al at the ground state are composed of ion-pair state expressed approximately by (Acδ−)(Mδ+): the electron is transferred from metal to the carbonyl group, suggesting that the carbonyl compound interacting with Ga and Al behaves as an n-type semiconductor. In the case of the Ac–B complex, on the other hand, the electron on Ac is significantly transferred to the boron atom, expecting that hole is transferred in the boron-doped carbonyl compound (p-type semiconductor). In these complexes, the first electronic transition is a charge-transfer band between metal and carbonyl group. The mechanism of the electronic conductivity was discussed on the basis of theoretical results.