Article ID Journal Published Year Pages File Type
1325576 Journal of Organometallic Chemistry 2014 11 Pages PDF
Abstract

•Eighteen camphor derived Zn(II) complexes were synthetized and characterized.•Some of the Zn camphor complexes catalyse the cyclization of 4-pentyn-1-ol.•The dinuclear camphor Zn(II) compounds are better catalysts than the mononuclear.•XPS studies and SEM images allow an insight into the surface of Zn complexes.

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(μ-Cl)2] where proton loss from MeHNNC10H14O occurs. The new complexes and camphor derivatives were characterized by IR, NMR (1H, 13C{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.

Graphical abstractCamphor derived ligands coordinate Zn(II) forming complexes with different metal to ligand ratios. The binuclear complexes with bi-camphor type ligands are efficient catalysts for cyclization of 4-pentyn-1-ol with further addition of a second alkynol molecule.Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Inorganic Chemistry
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