Synthesis, Characterization, and Molecular Modelling of Bis(Aquo)Tris(Dibutyldithiophosphato) Gadolinium (III)

Characterization of the compound formed in the reaction between the ligand di-n-butyldithiophosphoric acid (DBDTP) and gadolinium(III) ion, and a prediction of the possible molecular structure of the synthesized compound, using molecular modelling have been carried out. Ultraviolet spectra of the resulted compound showed a bathochromic shift from 197.3 to 210.0 nm, due to the formation of Gd-S bonds. Infrared spectra of the compound showed absorptions at 1,494 and 1,394 cm-1, probably due to the in-plane vibration of Gd-S bonds. Mass spectra of the compound showed a peak at an m/z of 919.632, which corresponds to the calculated molecular mass of [Gd(DBDTP)3(H2O)2]. X-ray powder diffraction measurements showed that the compound had a hexagonal shape with the lattice parameters a = 9.97 and c = 9.09 Å. From the experimental results, including those of molecular modelling, it can be drawn a conclusion that the complex molecule consisted of one gadolinium atom, which bound three di-n-butyldithiophosphate and two water ligand molecules.