Recent Advances on Palladium(II) Complexes with Substituted Dihydrobenzoimidazo Quinazoline Derivatives: Synthesis, Characterization and Its Biological Activity

This chapter highlights about Synthesis and Characterization of Palladium (II) Complexes with Substituted Dihydrobenzoimidazo Quinazoline Derivatives. The heterocyclic compounds have a great importance in medicinal chemistry. One of the most important heterocycles in medicinal chemistry are quinazolines possessing wide spectrum of biological properties like antibacterial, antifungal, anticonvulsant, anti-inflammatory, anti-HIV, anticancer and analgesic activities. A series of palladium(II) halo complexes of the types [PdX2L2].nH2O {n = 0, X = Cl, L = L2, L4 and L5; X = Br, L = L2; n = 1, X = Cl, L = L1 and L3} and Pd2X4L3 [X = Br, L = L1, L3, L4 and L5] were prepared where L is 6-R-5,6- dihydrobenzoimidazo quinazoline (R-Diq; where R = ethyl: L1/ n or i-propyl: L2, L3/ n or i-butyl: L4, L5) and characterized by elemental analyses, conductivity measurements, TGA, infrared, electronic, NMR and mass spectral techniques. The infrared spectra of the complexes exhibited peaks similar to those of the uncoordinated N- heterocycles L1 to L5 except for minor shifts implying the coordination of the ligands to palladium (II) ion. Based on these investigations, square planar monomeric or dimeric structures with the metal ion in the center were postulated for all of the complexes. It was determined whether some complexes have anti-microbial properties. The Pd(II) complexes were found to be effective against the microbes at 100 ppm concentration. It was observed that the Pd(II) complexes exhibit lower inhibitory activity as compared to those of the quinazoline derivatives.