title: Synthesis, antimicrobial activity, structural and spectral characterization and DFT calculations of Co(II), Ni(II), Cu(II) and Pd(II) complexes of 4-amino-5-pyrimidinecarbonitrile.
abstract: Co(II), Ni(II), Cu(II) and Pd(II) complexes of 4-amino-5-pyrimidinecarbonitrile (APC) have been synthesized and characterized using elemental analysis, magnetic susceptibility, mass spectrometry, infrared (4000-200 cm(-1)), UV-Visible (200-1100 nm), (1)H NMR and ESR spectroscopy as well as TGA analysis. The molar conductance measurements in DMSO imply non-electrolytic complexes, formulated as [M(APC)2Cl2] where M=Co(II), Ni(II), Cu(II) and Pd(II). The infrared spectra of Co(II), Ni(II) and Cu(II) complexes indicate a bidentate type of bonding for APC through the exocyclic amino and adjacent pyrimidine nitrogen as donors whereas APC coordinated to Pd(II) ion as a monodentated ligand via a pyrimidine nitrogen donor. The magnetic measurements and the electronic absorption spectra support distorted octahedral geometries for Co(II), Ni(II) and Cu(II) complexes however a square planar complex was favored for the Pd(II) complex (C2h skeleton symmetry). In addition, we carried out B3LYP and ω-B97XD geometry optimization at 6-31G(d) basis set except for Pd(II) where we implemented LanL2DZ/6-31G(d) combined basis set. The computational results favor all trans geometrical isomers where amino N, pyrimidine N and Cl are trans to each other (structure 1). Finally, APC and its divalent metal ion complexes were screened for their antibacterial activity, and the synthesized complexes were found to be more potent antimicrobial agents than APC against one or more microbial species.
authors.affiliation: Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City 11884, Cairo, Egypt. Electronic address: tarek_ama@hotmail.com.
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Mohamed
authors.affiliation: Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City 11884, Cairo, Egypt.
authors.forename: Ibrahim A
authors.initials: IA
authors.lastname: Shaaban
authors.affiliation: Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City 11884, Cairo, Egypt.
authors.forename: Rabei S
authors.initials: RS
authors.lastname: Farag
authors.affiliation: Department of Chemistry, Sultan Qaboos University, P.O. Box 36, Al Khod, Oman.
authors.forename: Wajdi M
authors.initials: WM
authors.lastname: Zoghaib
authors.affiliation: Department of Chemistry, Faculty of Science (Men's Campus), Al-Azhar University, Nasr City 11884, Cairo, Egypt.
authors.forename: Mahmoud S
authors.initials: MS
authors.lastname: Afifi
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005658:Fungi / Q000187:drug effects; D007700:Kinetics; D008024:Ligands; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008968:Molecular Conformation; D009532:Nickel / Q000494:pharmacology; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010165:Palladium / Q000494:pharmacology; D066244:Proton Magnetic Resonance Spectroscopy; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
chemical_list: C000598708:4-amino-5-pyrimidinecarbonitrile; D000890:Anti-Infective Agents; D056831:Coordination Complexes; D008024:Ligands; D009570:Nitriles; D011743:Pyrimidines; D003035:Cobalt; D010165:Palladium; D003300:Copper; D009532:Nickel
keywords: 4-Aminopyrimidine-5-carbonitrile; Antimicrobial activities; DFT calculations; IR, Vis and ESR spectra; Metal complexes