Spectrophotometric and electrical studies of charge transfer complexes of 2-amino-1,3,4-thiadiazole with pi-acceptors.

Charge transfer (CT) complexes formed between 2-amino-1,3,4-thiadiazole as donor and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), p-chloranil (p-CHL), o-chloranil (o-CHL), p-bromanil (BRL) and chloranilic acid (CHA) as acceptors, have been studied spectrophotometrically. Benesi-Hildebrand and Job continuous variation methods were applied to the determination of association constant (K), molar extinction coefficients (epsilon), dipole moment and stoichiometric ratio, respectively. The solid CT complexes have been synthesized and characterized by different spectral methods. The spectral changes reveal that the CT interaction depends on the type of the acceptors. The magnetic properties of the various complexes were also investigated. The electrical properties for the solid CT complexes are measured from which the activation energies are calculated.