| Abstract |
Zinc(II) complexes of general formula [ZnX2(YNC10H14O)], [ZnX2(YNC10H13NSO2)], [ZnX2(H2NNC10H14O)(2)], [\ZnX2\(2)(YNC10H14O)] and [\ZnX2\(2)(YNC10H13NSO2)] were obtained from zinc halides (chloride or bromide) by reaction with the suitable camphor ligands. In most of the complexes, the camphor ligands remain unchanged upon coordination, except in [\Zn(MeNNC10H14O)\(2)(mu-Cl)(2)] where proton loss from MeHNNC10H14O occurs. The new complexes and camphor derivatives were characterized by IR, NMR (H-1, C-13\H\, DEPT, 2D) and elemental analysis. In some cases the surface composition was studied by X-ray photoelectron spectroscopy (XPS) and imaged by Scanning Electron Microscopy (SEM). Images of [ZnCl2(Me2NNC10H14O)] and [ZnCl2(Me2NNC10H13NSO2)] obtained by SEM show the solid particles have tubular structures capped in one or both extremities. The coordination of THF in [ZnCl2(YNC10H14O) THF] was confirmed by X-ray diffraction analysis. The camphor derivatives YNC10H14NSO2 (Y = NMe2; NHMe) and p-C6H4(NC10H14O)(2) were structurally characterized by X-ray diffraction analysis. The ability of selected Zn(II) camphor complexes to catalyse the cyclization of 4-pentyn-1-ol was evaluated showing that the binuclear complex [\ZnX2\(2)(YNC10H14O)] performs better than the mononuclear Zn(II) complexes. (C) 2013 Elsevier B.V. All rights reserve. |
