Solvatochromism and ionochromism of the nile blue dye a through raman, infrared and uvvis spectroscopies

Abstract

The present work presents the systematic study of Nile Blue A (NB) dye, a cationic textile dye, through electronic and vibrational spectroscopies (Raman, resonant Raman scatter and infrared absorption) in the presence of distinct anions (chloride, bromide, perchlorate and sulfate) and protic and aprotic solvents of different polarities (water, ethanol, acetone, acetonitrile, chloroform and ethyl acetate). There were vibrational changes resulting from the formation and destruction of aggregates according to the chemical environment, besides the formation of a molecular conformation with higher energy in apolar aprotic solvents.