Synthesis and crystal structure of bis [2-(4-methylphenyl)-1-phenethyl-4(1H)-quinazolinone] dichlorocopper (II)

The title complex, bis [2-(4-methylphenyl)-1-phenethyl-4(1H)-quinazolinone] dichlorocopper (II) was synthesized and characterized by single-crystal and powder X-ray diffraction, IR–UV spectra, elemental analyses, 1H and 13C NMR and thermogravimetric analyses. Crystal structure determination reveals that the complex consists of mononuclear units with copper (II) ion coordinating in a bis-bidentate fashion. The copper (II) ion is located on the inversion center and has an octahedral coordination environment. The conformation of the dihydropyrimidine (DHPM) ring is almost planar unlike a sofa, as in the case of pure ligand. No classical hydrogen bonds were observed in the structure. The optimized geometrical parameters were calculated using the methods based on the density functional theory (DFT). A comparison of the molecular conformation and geometrical parameters obtained from the X-ray structure analysis and the theoretical study clearly indicates that the DFT calculations agree closely the X-ray structure. The investigated complex along with the ligand has been screened simultaneously for in vitro antibacterial and antifungal activities and compared with the drugs in use.

The synthesis, crystal structure and physical characterization of the copper (II) complex with a bidentate ligand are described. X-ray data have been compared with DFT calculations. Antimicrobial studies have been carried out. Structure–activity correlation has been done in the light of ligand–metal complexation.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of bis[2-(4-MePh)-1-Phenethyl-4(1H)-quinazolinone] Cu(II)Cl2 is reported.
► X-ray structure analysis revealed the geometry of the metal-coordination is octahedral.
► NMR study confirms metal coordination via deprotonation.
► DFT-B3LYP/6-31G calculations show good agreement with the experimental X-ray data.
► Antimicrobial studies show some encouraging results.