Novel pyrazolo pyrazoly heterocyclic in the synthesis of positive solvatochromic cyanine dyes
R. M. Abdel Aal, I. I. Abd El Gawad and Z. M. Essam
Novel cyanine dyes monomethine, bismonomethine and trimethine cyanine dyes were synthesized from 5-hydroxy-2-(5-hydroxy-3-methyl-1-phenyl-4,5-dihydro1H-pyrazol-4-yl)-3-methyl-1-phenyl-4,5-dihydro-1H-pyrazol-2-ium as a nucleus.
Structure confirmed by elemental analysis, IR, 1H-NMR, mass and visible was determined. The electronic visible absorption spectra of all the newly synthesized cyanine dyes were investigated in 95% ethanol solution. Solvatochromism for the newly prepared cyanine dyes were performed in pure solvents having different polarities.