Synthesis, spectral and thermal study of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) complexes with mefenamic acid

Abstract

New binuclear complexes of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) ions with mefenamic acid were obtained in solid phase. For all compounds considered, complexation occurs at pH 6-6.5. The analyzed complexes were characterized on the basis of chemical and elemental analyses, molar conductance, UVVis, IR and 1H NMR spectroscopies as well as thermoanalytical techniques. According to the research results, the molecular formula of the complexes is Ln 2 (C 15 H 14 NO 2 ) 3 (OH) 3 9nH 2 O, with the exception of the La(III) complex which has the formula La 2 (C 15 H 14 NO 2 ) 5 (OH). The results show that only the carboxyl group is involved in the coordination of the rare earth ions in the bidentate mode. Coordination does not occur through the nitrogen atom. All the complexes are soluble in DMSO, and they are nonelectrolytes. The TG-FTIR technique was employed in order to study a decomposition pathway of the obtained compounds. The received results provide information on the composition, thermal stability, thermal decomposition, as well as the gaseous products that evolved during the thermal decomposition of the considered compounds.

Synthesis, thermal behavior and spectroscopic investigations of metal complexes with N-modified glycine as ligand

“…The UV-VIS spectra in CH 3 OH abs for the complexes (1-3) indicate a slight bathochromic shift by 4-6 nm, but a considerable hyperchromic increase effect of absorbance comparative to the spectrum of the initial ligand (L), like the other similar complexes [4,11,12]. The shift of n ͢ ͢ → π * characteristic band in the UV spectra attributed to the C=O bond (262.4 nm for the ligand; lit.…”

Complexes of selected transition metal ions with n-modified glycine as ligand

“…The UV-VIS spectra in DMSO for the complexes (1-5) indicate a slight hypsochromical shift by 3.5-7.5 nm, but a considerable hyperchromic increase effect of absorbance comparative to the spectrum of the initial ligand (L), except Zn complex, like the other similar complexes [3,12,14,15].…”

Infrared Spectroscopic Study of Binding Interaction of Metal Complexes with Mefenamic Acid (MFA)

“…4-hydroxycoumarin with mefenamic acid exacerbates GI problems [18]. It is well known that transition metal complexes with nonsteroidal medicines are more efficacious and less toxic than their parent medications [19].…”

“…, 1651 cm -1 & 1577 cm -1 wavelength and the combination gets effective changes that alter the whole result of the FT-IR pattern. So there is a possible interaction with C=O, C-N & C=C groups formed respectively by sp 3 , sp, and sp 2 hybridization [18]. .…”