Perylene bisimide dimers of the type shown in the structure below could be synthesized in high yield and purity by condensation of the corresponding monoimide-monoanhydride with diamines. Dimers in which R and X were alkyl, aryl aralkyl and substituted groups were prepared and characterized by absorption and emission spectroscopy. Like the corresponding monomeric bisimides the extent of Π-overlap (manifested in the pigment color) in the solid dimers is dependent on the structure of the terminal R-groups but is even more sensitive to the nature of the X-bridging group. Most notably, xerographic electrical evaluation of model devices showed that dimers in which X was 1,3-propylene generally showed broader visible spectral response and higher photosensitivity than dimers with other bridging groups.