The Electronic Structures of Permethyl Oligogermane Radical Cation with Longer Chains

Abstract

Hybrid density functional theory (DFT) calculations have been carried out for neutral and radical cation of permethyl-oligogermane, Ge_n(CH₃)_2n+2 (n = 4–28), to elucidate the electronic structures at ground and low-lying excited states. It was found that a hole is distributed in both the Ge-Ge skeleton (main chain) and methyl group (side chain) in the case of shorter chain-lengths below n = 8, whereas the spin density (hole) in the methyl group becomes significantly smaller in longer chain-lengths (n > 10). The IR-band of radical cation were assigned on the basis of theoretical calculations.

Keywords:

• oligogermane
• hole transfer
• radical cation
• DFT
• PBC

Acknowledgments

The authors are indebted to the Computer Center at the Institute for Molecular Science (IMS) for the use of the computing facilities. One of the authors (H.K) acknowledges a partial support from a Grant-in-Aid for President's optional budget from Kyoto University. Another author (H.T) also acknowledges a partial support from a Grant-in-Aid for Scientific Research (C) from the Japan Society for the Promotion of Science (JSPS).