Combined experimental and theoretical investigations on 9-[3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,9-dihydro-6H-purin-6-one 4-nitrophenol (IPNP) molecule

Abstract

Inosine and p-nitrophenol were taken in equimolar ratio to synthesize 9-[3,4-dihydroxy-5-(hydroxyme-thyl)oxolan-2-yl]-1,9-dihydro-6H-purin-6-one 4-nitrophenol via solvent vaporization technique. The synthesized material was subjected to single-crystal X-ray diffraction analysis, which confirms that it is crystallized in a monoclinic crystal system with space group P21. Hirshfeld analysis showed that molecule had close contacts of O···H/H···O, amounting to 45.7%, observed over dnorm surface with red spots owing to intermolecular hydrogen bonding. 1H NMR and 13C NMR analysis confirmed the structure of the IPNP molecule. The signal at δ 162.82 ppm confirmed the presence of hydroxyl group attached carbon in p-nitrophenol. FTIR spectroscopy confirmed the presence of all functional groups in the molecule. The broad band at 3334 cm−1 is due to OH stretching and the strong peak at 1694 cm−1 is owing to NO stretching. Density functional theory calculations performed by Becke-3-Lee-Yang-Par (B3LYP) level and M06-2X, combined with the standard 6-31G (d,p) basis set on IPNP molecule correlated well the with experimental data. UV-Vis spectrum showed absorption at 244 and 318 nm, which are due to n→π* and π→π* transition in the molecule. The HOMO-LUMO energy gap was 4.561 eV. A fluorescence peak was observed at 385 nm with an energy gap of 3.21 eV via photoluminescence spectroscopy. The antibacterial activity tests indicated that IPNP inhibited both Vibrio alginolyticus and Staphylococcus aureus bacteria.