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Guveli, Sukriye/0000-0001-7384-822X; Ulkuseven, Bahri/0000-0001-6342-1505; Ozdemir, Namik/0000-0003-3371-9874 WOS: 000377728600003 Two nickel(II) complexes containing 5-bromosalicylidene-N-methyl-S-methyl-isothiosemicarbazone (H(2)SMeNMeTsc) and 5-bromosalicylidene-N-methyl-thiosemicarbazone (H(2)NMeTsc) with triphenylphosphine were synthesized. The compounds were characterized by elemental analysis, IR, H-1 NMR and UV-Vis spectroscopies, and their structures were determined by single crystal X-ray diffraction technique. Theoretical characterization of the compounds was carried out using the density functional theory (DFF/B3LYP) method with 6-311G(d,p) basis set for the C, H, Br, N, O, P, S atoms and LANL2DZ pseudo-potential for Ni atom, and the results were checked against the experimental data. Electronic absorption spectra of the compounds have also been obtained using the time-dependent density functional theory (TD-DFT) formalism at the same level. The coordination geometry around Ni-II in the two complexes is distorted square-planar geometry. While the thiosemicarbazone ligand is coordinated to nickel through ONN mode in [Ni(SMeNMeTsc)(PPh3)]center dot PPh3, it is bound to the metal as dianionic ONS donors in [Ni(NMeTsc)(PPh3)]. The consistency between theoretical and experimental values is good in general. (C) 2016 Elsevier Ltd. All rights reserved. Scientific Research Projects Coordination Unit of Istanbul UniversityIstanbul University This work was supported by the Scientific Research Projects Coordination Unit of Istanbul University. We also thank Associate Professor Mustafa Serkan Soylu, Giresun University, Turkey, for his help with the X-ray data collection of complex [Ni(SMeN-MeTsc)(PPh3)]center dot PPh3.

The complexes [Ni(L1)(PPh3)] (1) and [Ni(L2)(PPh3)]·HCl (2) were synthesized by the reaction of [Ni(PPh3)Cl2] and dibasic 2-hydroxyacetophenone-S-R-4-R1-thiosemicarbazones (R/R1: H/CH3, L1H2; CH3/H, L2H2). The ligands and the complexes were characterized using elemental analysis, IR and 1H NMR spectra. In both complexes, the thiosemicarbazone ligands coordinate to nickel(II) by giving two protons. Complex 1 is formed through the phenolate oxygen, azomethine nitrogen and sulfur atoms of L1 and the P atom of a triphenylphosphine ligand. In complex 2, L2 is functional through an ONN donor set, containing a thioamide nitrogen instead of a sulfur atom. X-ray analysis indicated distorted square planar structures for the complexes, and the nickel atoms lie slightly above the planes structured by the donor atoms. In the crystal forms of 1 and 2, some phenyl ring protons of the phosphine ligand give intramolecular hydrogen bonds with the donor atoms of the thiosemicarbazone moiety, namely the phenolate oxygen (in complexes 1 and 2) and N4 nitrogen (in complex 2).

Ozdemir, Namik/0000-0003-3371-9874; Andac, Omer/0000-0003-3641-9690; Ulkuseven, Bahri/0000-0001-6342-1505; Guveli, Sukriye/0000-0001-7384-822X WOS: 000280898800002 Reaction of 2-hydroxyacetophenone thiosemicarbazone with [Ni(PPh(3))(2)Cl(2)] in optimized conditions afforded a mixed ligand complex with an isolated triphenylphosphine molecule. The structure was characterized by elemental analysis, IR, NMR and UV-Vis. spectroscopies and single crystal X-ray diffraction technique. In addition, the molecular geometry, vibrational frequencies and gauge including atomic orbital (CIAO) (1)H and (13)C NMR chemical shift values of the title compound in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-31G(d,p) basis set for the C. N, O, S, P. H atoms and LANL2DZ pseudo-potential for the Ni atom, and compared with the experimental data. Besides, atomic charge distributions, molecular electrostatic potential and frontier molecular orbitals (FMO) analysis of the title compound were investigated by theoretical calculations. The thermodynamic properties of the compound at different temperatures have been calculated and corresponding relations between the properties and temperature have also been obtained. Atomic charge distributions indicate that during forming the title compound, the free ligand of thiosemicarbazone ion transfers their negative charges to central Ni(II) ion. The effect of different solvents (chloroform, methanol and water) on the geometry, vibrational frequencies, total energies and dipole moments was studied using the density functional theory (DFT/B3LYP) method by applying the Onsager and the Polarizable Continuum Model (PCM). (C) 2010 Elsevier Ltd. All rights reserved. istanbul UniversityIstanbul University; Research Centre of Ondokuz May's UniversityOndokuz Mayis University [F-461] Funding of our research from the Research Fund of istanbul University and the Research Centre of Ondokuz May's University (Project No: F-461) is gratefully acknowledged.