Spectroscopic Studies of Charge-Transfer Complexes of 2,3-Dichloro-5,6- Dicyano-P-Benzoquinone

摘要

In present work charge-transfer spectra of donors (p-acetotoluidide, acetanilide,biphenyl and naphthalene) with 2,3-dichloro-5, 6-dicyano-p-benzoquinone (DDQ) as acceptor were investigated. In each case two charge-transfer bands were observed. These investigations were made in three different solvents (CH2Cl2, CHCl3 and CCl4) and at two temperatures (25 degrees C and 20 degrees C or 30 degrees C). (delta)h(nu) values for p-acetotoluidide-DDQ, acetanilide-DDQ, biphenyl-DDQ and naphthalene-DDQ were measured. For these systems, values of ionization potentials of donors (I(sup D)), equilibrium constant for association (K(sub ass)) change in standard free energy (delta G degrees), change in standard entropy (delta S degrees) and change in standard enthalpy (delta H degrees) were also determined. Their magnitudes indicate similar trend as reported in othersystems in literature.