Seven novel pentamethine cyanine dyes with 3,5-dimethylpyridinium-1-yl, pyridinium-1-yl, and
1-quinolinum-1-yl substituents in the g position of the methine chain containing ester or carboxylic acid
groups in the ring of the dyes were synthesized via a three-step procedure. The visible spectral behavior
of the pentamethine cyanine dyes was examined in DMSO. Elemental analysis, IR, 1H-NMR, 13C-NMR,
and mass spectral (MS) data confirmed the molecular structure of the newly synthesized compounds.