G. OANCA^#, CLAUDIA NĂDEJDE, DORINA CREANGĂ

Faculty of Physics, “Alexandru Ioan Cuza” University, 11 Carol I Blvd., Iași, Romania

Caffeine is known as an important substance in human life with both alimentation and medical issues. Biophysical approach of caffeine molecule was carried out in this study by applying quantum chemical methods and spectral recording. The focus of the present investigation was the evidencing of the solvent action on the electronic absorption transition of caffeine in the near ultraviolet range – for practical applications in extractive industry and chromatographic analysis of the product. The nature of solvent solute interactions was revealed by means of mathematical modeling. Linear correlation coefficient of 0.99 was found to the application of solvatochromic model of Lippert-Mataga that allowed the estimation of dipole moment in the excited state (9.2130 D) – based also on the dipole moment in the ground state (3.906 D) estimated by quantum chemical method. The application of Bakhshiev’s solvatochromic model with linear correlation coefficient over 0.93 led to the evidence of universal solute-solvent interactions like induction forces and dispersive ones.

Corresponding author’s e-mail: oanca.gabriel@gmail.com

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