Molecular complexes of phenols with DDQ

Molecular complexes of phenols with DDQ have been studied spectrophotometri cally in the temperature range of 10-30 degrees C in a solvent (CHCl3) of l ow polarity under low donor concentrations. All the complexes exhibit one C T band each in the wavelength region where acceptor and donor do not have a ny absorption. The complexes are inferred to be of the pi-pi type and have R-y configuration in which the donor molecular orbital encompasses the subs tituent. The ionization potentials of the donors, the stability constants a nd thermodynamic parameters of the complexes have been evaluated.