Synthesis and semi-empirical sparkle PM6 study of substituted dithiophosphoric compounds of gadolinium(III)

Seven gadolinium(III) derivatives containing dialkyl and alkylene dithiophosphate chelating ligands [S2P(OR)(2)](3)center dot 2CH(3)CN (R=Et, n-Pr, n-Bu and Ph) and [S2PORO](3)center dot 2CH(3)CN (R=CH2CMe2CH2, CH2CEt2CH2 and CMe2CMe2) have been synthesized. The metal complexes have been characterized by elemental analyzes, molecular weight determinations, IR, and UV-Visible spectroscopy. Microanalytical data revealed a 1:3 metal-ligand ratio in all complexes. Geometries were fully optimized at the semi-empirical sparkle PM6 level of theory using MOPAC2009 and geometrical structures and electronic properties of the complexes have been evaluated. The optimized geometries were confirmed to be minima on the potential energy surfaces through frequency calculations. Absorption spectra of the complexes have been calculated using ORCA2.9 package utilizing the predicted optimized wave functions. Linear and nonlinear static optical susceptibilities for all complexes were calculated at the same level of theory. The polarizability invariants were, in general, well correlated with the molecular volume and the number of carbons within the alkyl moieties. The largest electric properties were exhibited by the phenyl dithiophosphate complex.