Electronic Properties of 3,3′,5,5′-Tetramethyl-Benzidine Complexes with TCNQ Derivatives

The electronic properties of the charge transfer complexes of 3,3′.5,5′-tetramethyl-benzidine (33′55′TMB) with five TCNQ derivatives (F4TCNQ, FTCNQ. TCNQ, Me2TCNQ and (MeO)2TCNQ) were investigated by electrical conductivities and electronic spectra measurements. 33′55′TMB-FTCNQ and 33′55′TMB-FTCNQ showed the relatively low resistivities. Two charge transfer bands were observed in the electronic spectra of these complexes. From the correlation between the observed first charge transfer band and the estimated one, it was found that FTCNQ and TCNQ complexes were in the intermediate state between ionic and non-ionic states. The relatively low resistivities of FTCNQ and TCNQ complexes among the benzidine complexes were confirmed to be caused by partial charge transfer.