Electronic and vibrational spectra of Et4N[Au(dmit)2TCNQ]

We present the results of spectral studies of Et4N[Au(dmit)2TCNQ] salt containing alternating stacks of Au(dmit)2 and TCNQ molecules. The polarized transmission spectra of single crystals are measured in the IR region (650 to 6500 cm-1) as a function of temperature (90 to 300 K). Moreover, the powder absorption spectra in the frequency range (400 to 40000 cm-1) are reported. From spectral evidence results that transferred electrons are localized on Au(dmit)2 molecules in the mixed stacks. The intrastack charge transfer between Au(dmit)2 and TCNQ molecules (approximately 8000 cm-1) and the interstack charge transfer transition between Au(dmit)2 molecules (approximately 5500 cm-1) are found. Interactions of electrons with intramolecular vibrations of TCNQ (ag modes) and Au(dmit)2 (C = C and C = S stretching) are suggested and discussed.