Electronic States of the Crystals of TCNE Complexes with Hexamethylbenzene, Acenaphthene, and Dibenzofuran

The polarized reflection spectra were measured on crystals of tetracyanoethylene and its charge-transfer complexes, and the absolute intensity of the absorption parallel to the crystalline axes has been obtained by the Kramers-Kronig transformation. The charge-transfer degree and the stabilization energy in the ground state were estimated for each complex by analyzing the charge-transfer bands in the crystalline state. In the TCNE–hexamethylbenzene(HMB), acenaphthene, and dibenzofuran complexes, the charge-transfer degrees are 9.05, 12.3, and 4.95% respectively in the ground state.