A study on the electronic spectra of some 2-azidobenzothiazoles, TD-DFT treatment

作者：Abu Eittah Rafie H^*; El Taher Sabry; Hassan Walid; Noamaan Mahmoud

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2015, 151: 916-925.

DOI：10.1016/j.saa.2015.06.119

• Azidobenzothiazoles
• Electronic absorption spectra
• sigma and pi electronic transitions
• TD/DFT-treatment

The electronic absorption spectra of some 2-azidobenzothiazoles were measured in different solvents. The effects of solvent and substitution on the spectra were investigated. Substitution by a bromine atom and by a nitro group have significant effects on both band maxima and band intensity. Correlation between the spectra of the studied compounds and the corresponding hydrocarbons proved to be weak, whereas the correlation between the observed spectra and those calculated is adequate.
Theoretical treatment of the ultraviolet spectra of the studied compounds was carried out by using the TD-DFT procedures, at the B3LYP level and the 6-311+G** basis sets, the results compared well with the experimental values. The computed molecular orbitals of the ground state indicate that some orbitals are "localized-pi" or "localized sigma" molecular orbitals while the others are delocalized orbitals. The calculated functions of the excited states lead to an accurate assignment of the bands observed in the spectra.

• 出版日期2015-12-5