Novel unsymmetric hetaryl LTAM molecules, (2Z, 2E)-2,2-(2-phenyl-propane-1,3-diylidene)bis(1,3,3-trimethylindoline) 5 and unsymmetric LTAM molecules, (2Z,2’E)-2-2’((E)-4-(4-nitrophenyl)pent-2-ene-1,5-diylidene)bis(1,3,3-trimethylindoline) 8 were prepared from the reaction of excess 5-substituted Fischer base (FB) with the conjugated dye molecules 4 and 7, respectively, via a Michael type reaction. Since the conjugated dye molecules is the α, β-unsaturated iminium salts, they behave like an α, β-unsaturated carbonyl compounds toward the Michael reaction. The compound 4 & 7 were obtained from the reaction of 1,3,3-trimethyl-2-styrylindolium perchlorate 2 and benzaldehyde or cinnamic aldehyde, respectively. Another rout for the conjugated compounds are the acid-catalized decomposition of the symmetric LTAM molecules 3 or 6, which was prepared from the Fisher base and the corresponding aldehydes.
The prepared molecules were characterized by 1H, 13C-NMR, IR, UV-Vis spectroscopy.