Abstract
Symmetrical bis-(styryl, tetramethine, aza-styryl) cyanine dyes (5a-g, 6a-c, 7a-c) containing arylidene, heterylidene and schiff base moieties have been obtained by the interaction of 4,9-dioxopiperidino [2,3-g]-1,2,3,4,6,7,8,9-octahydroquinolinoquinone 1 with aromatic aldehyde, heterocyclic aldehyde and nitroso compounds followed by condensation with 2(4)-methyl quaternary salts. The UV spectra in 95% ethanol of all the synthesized cyanine dyes show that the photosensitization of the dyes increases (or decreases) by increasing (or decreasing) conjugation, by the presence of electron donating (attracting) groups and the more (less) planarity of the dyes. The new compounds have been identified by elemental analysis, IR and H-1 NMR spectral data.