SYNTHESIS AND CHARACTERIZATION OF STILBAZ OLIUM DYES WITH MESOIONIC 1,2-DIAZINIUM STRUCTURE

Pyridazinium salts of typ 1 react with substituted aromatic and hetero aromatic aldehydes 2a, e-h, 8a-c and trans-p-dimethylamino-cinnamaldeh yde 3a to the charge transfer dyes 4a-h, 5a-d, 9a-c. They absorb in th e range between 380 and 660 degrees nm. The dehydratisation of the ald oxime group in 4, 5 to the nitril group under formation of 6, 7a-d cau ses a bathochromic shift of the absorption band up to 110 nm. The UV-V IS data are discussed dependent on the structure of the dyes.