J. Phys. I France
Volume 6, Numéro 12, December 1996
Page(s) 1643 - 1653
DOI: 10.1051/jp1:1996180
J. Phys. I France 6 (1996) 1643-1653

Electronic and Vibrational Spectra of Et $\mathsf{_4}$N[ Au(dmit) $\mathsf{_4}$TCNQ] Crystals

R. Swietlik1, A. Lapinski1, L.A. Kushch2 and E.B. Yagubskii2

1  Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan, Poland
2  Institute of Chemical Physics, Russian Academy of Sciences, 142 432 Chernogolovka, Russia

(Received 7 February 1996, revised 23 April 1996, accepted 3 June 1996)

We present the results of spectral studies of Et 4N[ 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 ( $\sim 8000~{\rm cm}^{-1}$) and the interstack charge transfer transition between Au(dmit) 2 molecules ( $\sim 5500~{\rm cm}^{-1}$) are found. Interactions of electrons with intramolecular vibrations of TCNQ (a ${\rm _g}$ modes) and Au(dmit) 2 (C = C and C = S stretching) are suggested and discussed.

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