Potassium complex containing 2,4-dimercaptopyrimidine as ligand: synthesis, x-ray structure and DFT calculations (B3LYP/LanL2DZ)

Abstract

The reaction of 2,4-dimercaptopyrimidine with potassium borohydride K[BH4] led to the formation of a new polymeric potassium complex. The obtained adduct was characterized by infrared spectroscopy (FT-IR), UV–Vis and single crystal X-ray diffraction, where it was possible to confirm the formation of the product with the following crystallographic parameters: a = 10.4286(16) Å, b = 14.417(2) Å, c = 8.5745(13) Å, α = 90°, β = 108.032(3) ° and γ = 90°. The geometry of the complex, the energy of the Kohn-Sham orbitals (HOMO and LUMO), and the electrostatic potential map (MEP) were calculated using the Density Functional Theory (DFT) at the theoretical level B3LYP/LanL2DZ and the structural parameters are close to those experimentally obtained. Comparison of the formation energies of the title complex and the scorpionate hydrotris{2,4(1H,3H)-pyrimidinedithione}borate, another possible product of the same reaction, indicates that the potassium complex is more favorable by around Hartree.