A study of the solvent effect on the low temperature spectra of benzoanthracene molecules

Asmaa N Ahmed

doi:10.30723/ijp.v12i24.315

Abstract

been taken at room temperature down to liquid nitrogen temperature (77K). Polar and nonpolar solvents have been used to study the solvent effect on the absorption and fluorescence spectra of solute molecules. Some of the spectroscopic parameters have been determined as functions of solvent polarity and temperature. The results indicate that the band width FWHM increases with increasing the solvent polarity and temperature, while the peak emission cross section decreases with increasing of solvent polarity and decreases with increasing the temperatures. Clear vibrational structure spectra of benzoanthracene molecules have been observed in Nonane and Hexane solvents at 77K.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are usually defined as a group of chemicals consisting of two or more benzene rings (C6H6) [1]
In addition to the spectral shifts, the vibrational structure of the fluorescence and absorption spectra are influenced by interactions with the solvent environment
While the peak emission cross section decreases with increase of solvent polarity at different temperatures

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are usually defined as a group of chemicals consisting of two or more benzene rings (C6H6) [1]. The molecular spectra of aromatic compounds can be studied in solid, liquid or vapour states. They may be studied under other suitable conditions in solid solutions or in a matrix of noble gas [4]. In addition to the spectral shifts, the vibrational structure of the fluorescence and absorption spectra are influenced by interactions with the solvent environment. The Shpol’skii spectra allow the determination of the structure of electronic and vibrational levels in complex organic molecules with high accuracy and the investigation of various manifestations of fine intra-and intermolecular interactions. The vessel was re- immersed in liquid nitrogen and the system is re-evacuated by connecting it again to the vacuum line.

PMT meter

Absorption spectra

Conclusions