Polymethin Dyes Derived from 6-Methylphenanthridine

Department of Chemistry, Government College, Sundergarh Manuscript received 4 April 1977, revised 7 September 1971. accepted 24 February 1978 A number of polymethin dyes derived from 6-methyl-phenaothridine as the fixed basic nucleus have been prepared and their absorption maxima data were determined. The absorption maxima data have been utilised for determination of relative basicities of different basic nuclei as well as for determination of relative acidities of different acidic nuclei. These dyes are expected to be good photographic sensitisers.