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 1 H NMR spectral data.