Solvatochromic behavior on the absorption and fluorescence spectra of Rose Bengal dye in various solvents

M. A. Rauf, John P. Graham, Saeed B. Bukallah, Mariam A.S. Al-Saedi

Research output: Contribution to journalArticlepeer-review

63 Citations (Scopus)


The absorption and fluorescence spectra of Rose Bengal dye were studied in various solvents. It was found that solvent effects on the absorption wavelength are consistent with the solvatochromic model of Kamlet, Abboud and Taft. The solvent polarizability value π* was found to have a linear relationship with the absorption wavelength of the dye in various solvents. Additionally, the normalized transition energy value (ETN) showed some scattering when plotted versus Δνaf. Density functional calculations were used to assign the absorption in the region 540-570 nm to a π-π* transition between the HOMO and LUMO of the anion. Experimental ground state and excited state dipole moments were calculated by using the solvatochromatic shifts of absorption and fluorescence spectra as a function of the dielectric constant (ε) and refractive index (n). The dipole moment for Rose Bengal was found to be 1.72 Debye in the ground state, whereas this value was 2.33 Debye in the excited state.

Original languageEnglish
Pages (from-to)133-137
Number of pages5
JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Issue number1
Publication statusPublished - Feb 2009


  • Absorption
  • Density functional theory
  • Dipole moments
  • Dyes
  • Fluorescence
  • Rose Bengal

ASJC Scopus subject areas

  • Analytical Chemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Spectroscopy


Dive into the research topics of 'Solvatochromic behavior on the absorption and fluorescence spectra of Rose Bengal dye in various solvents'. Together they form a unique fingerprint.

Cite this