3,4,9,10-Perylenetetracarboxylic acid derivatives and their photophysical properties

The aggregation in solutions of perylene pigments N,N′-diphenyl-, N,N′-dibenzyl- and N,N′-diphenethyl-3,4,9,10-perylenetetracarboxylic acid diimides in chloroform and dimethylsulfoxide solutions was studied. UV/Vis absorption spectra at different concentrations were recorded and it was shown that pigment molecules underwent aggregation to form dimers at larger solution concentrations. Monomer and dimer spectra of the pigments as well as aggregation degrees n and equilibrium constants K were calculated employing concentration-dependent measurement data of pigment solutions. Single- and dual-layered photoreceptors employing 3,4,9,10-perylenetetracarboxylic acid derivatives as charge-generating materials were prepared and their xerographic characteristics were measured. Incorporating a charge blocking layer into the dual-layered photoreceptors led to the enhanced photosensitivity, but a faster dark decay of the initial surface potential as well as slightly inferior homogeneity of the system was also observed.