Investigation of the nature of the unpaired electron states in the organic semiconductor N-methyl-N-ethylmorpholinium-tetracyanoquinodimethane

Abstract

Rice, M. J.; Yartsev, V. M.; Jacobsen, Claus Schelde

Temperature Study of the Polarized Reflectivity of TEA(TCNQ)2Single Crystal

“…Therefore, it would be interesting to study the manifestation of these changes in the model describing the electron-molecular vibration coupling. For a start we have attempted to interpret the data in terms of the dimer model derived by Rice et al [31,32].…”

Electron-molecular vibration coupling in (DMtTTF)Br and (o-DMTTF)2[W6O19] salts studied by vibrational spectroscopy

“…Originally developed for the salt K-TCNQ, with its well-isolated (TCNQ) 2 2-dimers, the latter isolated dimer model provided a means by which the experimental determination of the coupling constants in this material could be achieved [7]. In addition to doubly-charged TCNQ dimers, the model also found utility in salts having TCNQ dimers containing one electron as the totally symmetric TCNQ vibrations were found to couple to the charge transfer between the charged and neutral molecules [9].…”

Application of the Dimer and Tetramer Models for Interpretation of the IR Spectra of TEA(TCNQ)2

“…The theory [2,3] of the optical properties of those compounds predicts sharp peaks in the polarized optical reflectance spectrum as a consequence of a coupling of the radical electrons to the totally symmetric (ag) internal modes of vibration. Each dimer is assumed to be described by the…”

“…The monomers in a dimer were assumed to be identical, therefore the frequencies ωα,i were the same for the sites i = 1, 2. Consequently, the complex conductivity along the stack direction is [3] Here Nd denotes the number of dimers per unit volume, a is interplanar spacing in dimers. ωCT and ΓCT are, respectively, the energy and phenomenological natural width of the CT excitation, t is the transfer integral in the dimer, while y« denotes the phenomenological natural width of the antisymmetric vibration mode a of the dimer (the symmetric vibrations of the dimer do not couple with the intradimer electron excitations).…”