Spectroscopic and DFT Study of Alizarin Red S Complexes of Ga(III) in Semi-Aqueous Solution

A combined spectroscopic and computational approach has been used to study in detail the complexation between Ga(III) ARS solution. The NMR results revealed formation of four Ga(III)/ARS complexes, at pH 4, differing their metal:ligand stoichiometries or configuration, point a coordination mode through ligand positions C-1 C-9. For equimolar solutions, 1:1 [Ga(ARS)(H2O)4]+ complex was formed, while for 1:2 molar ratio [Ga(ARS)2(H2O)2]− complex, which two ligands are magnetically equivalent, is proposed. Based on DFT calculations, it determined that this centrosymmetric structure with an anti configuration. solutions 1:3 ratio, isomeric [Ga(ARS)3]3− complexes were detected by NMR, have mer fac configuration around metal centre. calculations provided structural details support proposal 1,9 mode. infrared spectroscopy results, together calculation spectra theoretically proposed structures, give further conclusions above. Changes UV/vis absorption fluorescence upon highly sensitive fluorescent probe detection Ga(III).