Novel dyes derived from hydrazones.: Part 4.: Synthesis and characterizations of 2-{4-[(2E)-2-(1-arylylidene)hydrazino]phenyl}ethylene-1,1,2-tricarbonitrile

Novel tricyanovinyl derived from hydrazones have been prepared by the reaction of tetracyanoethylene and phenylethylidene hydrazone, and these dyes showed absorption in the region of 500-593 nm. The dyes showed pronounced solvatochromic effects as the polarity of the solvents increased. Some of the new dyes were studied to show the aggregation properties in solution as the concentration changed. Most of the dyes studied showed change in the absorption spectrum and hence the position of the maximum absorption bands. The thermal stability of some of the prepared dyes was studied in polymethylmethacrylate film at 80 degrees C the annulations on the aromatic group showed less thermal stability of the dyes. (c) 2005 Elsevier Ltd. All rights reserved.