Mehmet Sönmez

Synthesis, spectroscopic and biological studies on the new symmetric Schiff base derived from 2,6-diformyl-4-methylphenol with N-aminopyrimidine.

A phenol based novel Schiff base polydentate symmetric ligand was prepared. The complexes were prepared by reacting ligand and the metal chlorides of Cu (II), Ni(II), Co(II) and Fe(II) in methanol to get a series of mononuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, NMR and API-ES mass spectral data. The mononuclear structure of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility and API-ES mass spectral data. The ligand and all the metal complexes were evaluated for their antimicrobial activity against four Gram-positive bacteria (Staphylococcus aureus ATCC 6538, S. aureus ATCC 25923, Bacillus cereus ATCC 7064 and Micrococcus luteus ATCC 9345), one Gram-negative bacterium (Escherichia coli ATCC 4230), and three yeast (Candida albicans ATCC 14053, Candida krusei ATCC 6258 and Candida parapsilosis ATCC 22019) strains. Therefore, newly synthesized the ligand and two complexes [(Cu(II) and Co(II)] showed good biological activity against all tested bacteria and yeast strains.

Synthesis and Characterization of Cu(II), Co(II), Ni(II), and Zn(II) Complexes of a Schiff Base Derived from 1‐Amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one and 3‐Hydroxysalicylaldehyde

Cu(II), Co(II), Ni(II) and Zn(II) metal complexes of a new heterocylic Schiff base derived from 1‐amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one with 3‐hydroxy‐salicylaldehyde have been synthesized and characterized on the basis of elemental analyses, electronic, IR and 1H NMR spectra, molar conductivity measurements, magnetic moment measurements and thermogravimetric analyses (TGA). It has been found that the Schiff base behaves as a neutral bidentate (NO) or tridentate (ONO) ligand forming chelates with 1:2 (metal:ligand) stoichiometry and octahedral geometry. The conductivity data for the Ni(II) complex is consistent with that expected for a weak electrolyte.

Palladium(II) and platinum(II) complexes of a symmetric Schiff base derived from 2,6,diformyl-4-methylphenol with N-aminopyrimidine: synthesis, characterization and detection of DNA interaction by voltammetry.

The two new mononuclear complexes were prepared by reacting symmetric Schiff base, containing pyrimidine rings and the metal chlorides of Pd(II) and Pt(II) in methanol. The mononuclear structure of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, IR, UV-Vis, NMR, DTA/TGA and API-ES mass spectral data. The interaction of these metal complexes with fish sperm double-stranded DNA (dsDNA) was studied electrochemically based on the oxidation signals of guanine and adenine. Differential pulse (DP) voltammetry by using renewable pencil graphite electrode was employed to monitor the DNA interaction at the surface or in solution. The results indicate that Pd(II) and (Pt) complexes with Schiff base ligand having pyrimidine rings strongly interacted with DNA.

Synthesis, characterization, cyclic voltammetry, and antimicrobial properties of N-(5-benzoyl-2-oxo-4-phenyl-2H-pyrimidine-1-yl)-malonamic acid and its metal complexes

A new heterocyclic compound, N-(5-benzoyl-2-oxo-4-phenyl-2H-pyrimidin-1-yl)-malonamic acid, was synthesized from N-aminopyrimidine-2-one and malonyldichloride. Bis-chelate complexes of the ligand were prepared from acetate/chloride salts of Cu(II), Co(II), Ni(II), Mn(II), Zn(II), Cd(II), Fe(III), Cr(III), and Ru(III) in methanol. The structures of the ligand and its metal complexes were characterized by microanalyses, IR, NMR, API-ES, UV-Vis spectroscopy, magnetic susceptibility, and conductometric analyses. Octahedral geometry was suggested for all the complexes, in which the metal center coordinates to ONO donors of the ligand. Each ligand binds the metal using C=O, HN, and carboxylate. The cyclic voltammograms of the ligand and the complexes were also discussed. The compounds were evaluated for their antimicrobial activities against Gram-positive and Gram-negative bacteria, and fungi using microdilution procedure. The antimicrobial studies showed that Cu(II), Fe(III), and Ru(III) complexes exhibited good antibacterial activity against Gram-positive bacteria with minimum inhibitory concentrations between 20 and 80 µg mL−1. However, the ligand and the complexes possess weak efficacy against Gram-negative bacterium and Candida strains. As a result, we suggest that these complexes containing pyrimidine might be a new group of antibacterial agents against Gram-positive bacteria.

A novel one-pot synthesis of heterocyclic compound (4-benzoyl-5-phenyl-2-(pyridin-2-yl)-3,3a-dihydropyrazolo[1,5-c]pyrimidin-7(6H)-one): Structural (X-ray and DFT) and spectroscopic (FT-IR, NMR, UV-Vis and Mass) characterization Studies

In this study, the title compound named as 4-benzoyl-5-phenyl-2-(pyridin-2-yl)-3,3a-dihydropyrazolo[1,5-c]pyrimidin-7(6H)-one (C24H18N4O2) was both experimentally and theoretically investigated. The compound was synthesized and characterized by FT-IR, NMR ((1)H NMR, (13)C NMR and HETCOR-NMR), Mass spectroscopies and single-crystal X-ray diffraction methods. The compound crystallizes in the monoclinic space group P2(1)/n with a=6.1402 (3) Å, b=21.4470 (15) Å, c=15.0049 (8) Å and β=97.407 (4)°. The molecular geometry was obtained from the X-ray structure determination optimized using density functional theory (DFT/B3LYP) method with the 6-31+G(d, p) basis set in ground state. From the optimized structure, geometric parameters, vibrational wavenumbers and chemical shifts of molecule were obtained. Experimental measurements were compared with its corresponding the calculated data. An excellent harmony between the two data was ascertained. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs) and non-linear optical (NLO) properties of the title molecule were investigated by theoretical calculations at the B3LYP/6-31+G(d, p) level.

Synthesis and Characterization of Cu(II), Ni(II), Co(II), Mn(II), and Cd(II) Transition Metal Complexes of Tridentate Schiff Base Derived from O-Vanillin and N-Aminopyrimidine-2-Thione

Abstract Monobasic tridentate Schiff base ligand having ONS donor sequence was prepared by condensing N-aminopyrimidine-2-thione with o-vanillin. The complexes were formed by reacting ligand and the metal acetates of Cu(II), Ni(II), Co(II), Mn(II), and Cd(II) in methanol to get a series of mononuclear and dinuclear complexes. The characterization of ligand and metal complexes were carried out by elemental analyses, conductivity measurements, magnetic susceptibility data, FTIR, UV-vis, NMR, and API-ES mass spectral data. The structure of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, API-ES mass spectral data and thermal gravitational analysis (TGA). GRAPHICAL ABSTRACT

Experimental and theoretical studies of (E)-2-(2-hydroxystyryl)-6-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-1,2,4-triazin-3(2H)-one

Crystal structure of the title compound, C26H21N3O5, has been synthesized and characterized by FT-IR, (1)H NMR, (13)C NMR and X-ray single crystal determination. The molecular geometry was also calculated by using Gaussian 03 software and structure was optimized by using HF and DFT/B3LYP method with the 6-31G(d) basis sets in ground state. The comparison of the theoretical and experimental geometries of the title compound indicated that the X-ray parameters agree with the theoretically obtained values. It was seen that R(2) value changes from 0.015 to 0.021 Å for bond length and angle. The calculated vibrational frequencies are also in good agreement with the experimental results. The (1)H and (13)C NMR chemical shifts values of (E)-2-(2-hydroxystyryl)-6-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-1,2,4-triazin-3(2H)-one molecule have been calculated by the GIAO method. Besides, molecular electrostatic potential maps (MEP), Mulliken charges and Nonlinear Optical effects (NLO) analysis of the compound have been calculated by the HF and B3LYP/6-31G(d) methods.

Studies on Reactions of Pyrimidine Compounds: Synthesis and Reactions of 5-Benzoyl-4,6-Diphenyl-1,2,3,4-Tetrahydro-2-Thioxopyrimidine

The 5-benzoyl-4,6-diphenyl-1,2,3,4-tetrahydro-2-thioxopyrimidin ( 1 ) have been prepared via Biginelli cyclocondensation reaction in acetic acid under reflux condition in good yield (93%). Reactions of 1 and iodomethane to afford thiopyrimidine compounds 3 and 5 . Also, the acetylation of compounds 1 and 3 gave 3-acetyl thioxopyrimidine 2 and methylthiopyrimidine 4 , respectively. Thioxopyrimidine derivative 6 was synthesized from 1 and POCl3/DMF. Furthermore, the starting compound 1 were cyclized with various bromo compounds to the thiazolopyrimidine 7 , 8 , 9 and pyrimido[2,3-b]thiazine 10 derivatives, in approximately 55–78% yields. The purpose of synthesizing the thioxopyrimidine derivatives is because of the high biological activities. All of these derivatives have been characterized by analytical and spectroscopic studies and the reaction mechanism is discussed.

Synthesis and biological evaluation of a novel ONS tridentate Schiff base bearing pyrimidine ring and some metal complexes

The new Schiff base ligand (1-[[1-(5-chloro-2-hydroxyphenyl)ethyliden]amino]-4-phenyl-5-benzoyl-pyrimidine-2-thione) and its Cu(II), Co(II), Pd(II), and Mn(II) complexes were synthesized and characterized by elemental and molar conductance, UV–Vis, IR, NMR spectra, magnetic moment as well as mass spectra. While Pd(II) complexes exhibited square planar geometry, the others displayed octahedral geometry. The complexes showed nonelectrolytic behavior. All the compounds were evaluated for in vitro antimicrobial efficiency against Gram-positive bacteria, Gram-negative bacteria, and yeast using microdilution procedure. This study suggested that the [Co(L)2]·3H2O (1b) and [Mn(L)2]·2H2O (1d) complexes might be new potential antimicrobial substances against bacteria and fungi.Graphical Abstract

Synthesis, characterisation and antimicrobial activity 1-aminopyrimidine-2(1 H )-thione and its Co(II), Ni(II), Pd(II) and Pt(II) complexes

Metal complexes of 1-aminopyrimidine-2(1H)-thione were prepared from acetate salts of Co(II), Ni(II), Pd(II) and Pt(II) in methanol. Electronic spectral data and magnetic moment measurements suggest mononuclear square planar geometrical structures for the metal complexes. The ligand and all the metal complexes were evaluated for their antimicrobial activity. The newly synthesised ligand and the Co(II) complex showed moderate activity against all tested bacteria and yeast strains.