Synthesis, Thermal and Spectroscopic Studies of Lithium Salt of Naproxen.

Abstract

A new lithium salt was synthesized and characterized. The stoichiometry of the salt was LiNap . 1H 2 O. The salt was thermally stable until 260 °C and 275 °C in air and nitrogen atmospheres, respectively, and did not melt until decomposition. The salt was highly crystalline and the crystal had a prismatic form. A spectroscopic study of the compound was performed, which covered the UV, Vis, NIR and MIR regions. The fluorescence studies showed that the salt emitted at 356 nm when excited at 236 or 264 nm. This emission was assigned to the first singlet excited state to the singlet ground level state of the compound.

Thermal, spectroscopic and in vitro biological studies of the lanthanum complex of naproxen

“…Trivalent lanthanum have an f 0 electronic configuration, i.e., the core electronic structure has filled shells and as a result, no electronic transition appears in the ultraviolet and visible region, since higher energies are required to promote an electron from filled shells [23], therefore, the large bands that appears in the 230-385 nm range of the DR spectra, Fig. S4 (see Supplementary material), is assigned to the ligand → * and n → * transitions [24].…”