Novel carbocyanine and bis carbocyanine dyes: synthesis, visible spectra studies, solvatochromism and halochromism

Novel carbocyanine dyes (trimethine cyanine dyes) and bis carbocyanine dyes (bis trimethine cyanine dyes) derived from the nucleus of benzo[2,3-b; 2',3'-b'] bis furo[2,3-d]imidazoline-3,5,8,10-tetra one were synthesized. The electronic visible adsorption spectra of all the synthesized cyanine dyes were investigated in 95% ethanol solution. Solvatochromism and/or halochromism for some selected dyes were examined in pure solvents having different polarities (water, dimethylformamide, ethanol, chloroform, carbontetrachloride and dioxane) and/or in aqueous universal buffer solutions owing varied pH values (1.45, 2.03, 3.72, 5.09, 7.57, 8.91, 10.20 and 12.04 units), respectively. Structural confirmations were determined by elemental analysis, visible, mass, IR and 1H NMR spectral data.