Vibrational study on Zn(Pyrimidine)2Cl2, Pyrimidine-Al(OH)3 and Pyrimidine-(Al(OH)3)2 complexes

A molecular modeling analysis was performed via density functional theory (DFT), using B3LYP/6-31++G(d,p) basis set on Zn(PM)2Cl2, PM-Al(OH)3 and PM-(Al(OH)3)2 complexes (PM: Pyrimidine) in order to investigate monodentate and bidentate coordination effects on pyrimidine vibrational wavenumbers. The Zn(PM)2Cl2 complex was synthesized and the FT-IR and FT-Ra spectra were recorded which, when compared to the calculated wavenumbers of the model mono- and bidentate Al(OH)3 complexes, showed that pyrimidine behaved as a monodentate ligand. Anharmonic corrections to the calculated wavenumbers of the Zn(PM)2Cl2 complex were done and the results led to a good overall agreement with the observed wavenumbers. A complete assignment of the fundamentals was proposed based on the internal mode analysis done by Gaussian03 programme.