27 research outputs found

    Synthesis, characterization and DFT studies of the cobalt(III) complex of a tetrapodal pentadentate N4S donor ligand

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    The synthesis of the pentadentate ligand 2,6-bis(3,3-dimethyl-2,4-dioxocyclohexanyl)-4-thiaheptane (N(4)Samp) is described. The synthetic pathway involves the coupling of two 1,3-(dimethylenedioxy)-2-methyl-2-(methylene-p-toluenesulfonyl)propane moieties with sodium sulfide and subsequent synthetic elaboration to prepare the final N4S donor system. The cobalt(III) complex [Co(N(4)Samp)Cl](2+) has been prepared and subsequently crystallized as the tetrachlorozincate salt. The X-ray structure analysis confirms the pentadentate nature of the ligand and shows the thioether donor occupying one apex with four equivalent amine donors effectively occupying the equatorial plane of the molecule. The sixth coordination site is occupied by a chloro ligand. The electronic absorption and C-13 NMR spectra have been studied. DFT calculations have been employed to explore structural and mechanistic comparisons between [Co(N(4)Samp)Cl](2+) and an analogous pentaamine complex

    Embracing ligands. Synthesis, characterisation and the correlation between 59Co NMR and ligand field parameters of Co(III) complexes with a new class of nitrogen-thioether multidentate ligand

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    The syntheses of the hexadentate ligands 2,2,10,10-tetra(methyleneamine)-4,8-dithiaundecane (PrN(4)S(2)amp), 2,2,11,11-tetra(methyleneamine)-4,9-dithiadodecane (BuN(4)S(2)amp), and 1,2-bis(4,4-methyleneamine)-2-thiapentyl)benzene (XyN(4)S(2)amp) are reported and the complexes [Co(RN(4)S(2)amp)](3+) (R = Pr, Bu, Xy) characterised by single crystal X-ray study. The low-temperature (11 K) absorption spectra have been measured in Nafion films. From the observed positions of both spin-allowed (1)A(1g) --> T-1(1g) and (1)A(1g) --> T-1(2g) and spin forbidden (1)A(1g) --> T-3(1g) and (1)A(1g) --> T-3(2g) bands, octahedral ligand-field parameters (10D(q), B and C) have been determined. DFT calculations suggest that significant interaction between the d-d and CT excitations occurs for the complexes. The calculations offer an explanation for the observed deviations from linearity of the relationship between Co-59 magnetogyric ratio and beta(DeltaE)(-1) (beta = the nephelauxetic ratio; DeltaE the energy of the (1)A(1g) --> T-1(1g) transition) for a series of amine and mixed amine/thioether donor complexes

    Studies of factors which determine the distributions of three species of South Australian reptile ticks / by Robert Dale Sharrad

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    Typescript (photocopy)193 leaves : ill., maps ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 198

    Three instances of reptile ticks parasitising humans

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    Norval, Gerrut, Sharrad, Robert D., Gardner, Michael G. (2020): Three instances of reptile ticks parasitising humans. Acarologia 60 (3): 607-611, DOI: 10.24349/acarologia/20204389, URL: http://dx.doi.org/10.24349/acarologia/2020438

    Embracing ligands. Synthesis, characterisation and the correlation between 59 Co and NMR and ligand field parameters of Co(III) complexes with a new class of nitrogen-thioether multidentate ligand

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    The syntheses of the hexadentate ligands 2,2,10,10-tetra(methyleneamine)-4,8-dithiaundecane (PrN4S2amp), 2,2,11,11-tetra(methyleneamine)-4,9-dithiadodecane (BuN4S2amp), and 1,2-bis(4,4-methyleneamine)-2-thiapentyl)benzene (XyN4S2amp) are reported and th

    Synthesis, characterization and DFT studies of the cobalt(III) complex of a tetrapodal pentadentate N 4 S donor ligand

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    The synthesis of the pentadentate ligand 2,6-bis(3,3-dimethyl-2,4- dioxocyclohexanyl)-4-thiaheptane (N4Samp) is described. The synthetic pathway involves the coupling of two 1,3-(dimethylenedioxy)-2-methyl-2- (methylene-p-toluenesulfonyl)propane moietie
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