Electron‐molecular vibration coupling in the cation‐radical salt of a giant analogue of TTF with ClO anion

Abstract

A. GRAJA (a), v. M. YARTSEV4) (a, b), c. GARRIGOWLAGRANGE (b):Spectral studies of an ion-radical salt D-ClO, of a giant analogue (D) of TTF are performed in which the dihydro-TTF core is bearing the two conjugated 1,4-dithiafulvalen-6-yl side arms. Both IR absorption and electronic spectra of the donor molecule are measured; Raman scattering is also accomplished. Our main attention is paid to the electron-molecular vibration coupling in the D-C10, salt. It is shown that the idea of treating the donor molecules as an aggregate of two parts excited by the intramolecular charge transfer is an acceptable first approximation of the EMV coupling in the giant n-donor. The EMV coupling constants are calculated and compared with those determined for the parent TTF molecule.Les etudes spectroscopiques du sel d'ion radical D-C10, d'un analogue geant (D) du TTF sont realises dam lequel le coeur dihydro-TTF porte deux substituants 1,4-dithiafulven-6-y1 conjuguCs. Les absorptions IR et les spectres electroniques du donneur sont enregistres de mime que ceux de diffusion Raman. Plus particulitrement les couplages Clectron-vibration moleculaire (EMV) dans Ie sel D-CIO, sont 8tudiCs. On montre que I'hypothkse de concevoir la molecule de donneur comme resultant de la somme de deux parties excitkes par transfert de charge intramoleculaire constitue une bonne premiere approximation du couplage EMV dans le donneur gkant. Les constantes de couplage EMV sont calculees et comparees avec celles determinees dans la molecule parene de TTF.' ) Ul.