Stretch Out or Fold Back? Conformations of Dinuclear Gold(I) N-Heterocyclic Carbene Macrocycles

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• 作者：Stefanie Kobialka ; Christina M眉ller-Tautges ; Melanie T. S. Schmidt ; Gregor Schnakenburg ; Oldamur Holl贸czki ; Barbara Kirchner ; Marianne Engeser
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：July 6, 2015
• 年：2015
• 卷：54
• 期：13
• 页码：6100-6111
• 全文大小：719K
• ISSN：1520-510X

文摘

We report the synthesis and characterization of 12 new dinuclear gold(I) N-heterocyclic carbene (NHC) complexes and the corresponding imidazolium precursors. The focus lies in a systematic study of conformational changes and intra- and intermolecular gold鈥揼old and 蟺鈥撓€ interactions of dinuclear gold(I) carbene complexes. Common to all members of the series of gold macrocycles are NHC ligands on the basis of imidazole with ethyl side chains and bromide as well as hexafluorophosphate counterions, respectively. The compounds vary in the length of a flexible alkyl linker between the NHC units. For the methylene and ethylene bridged macrocycles, a ring inversion movement can be observed by VT-NMR. In total, 11 molecular structures have been characterized by X-ray diffraction. Open ring conformations with intermolecular 蟺鈥撓€ and Au鈥揂u interactions prevail, but a backfolded conformation with a short intramolecular Au鈥揂u distance has been found for the ethylene-bridged species. The presence of Au鈥揂u interactions could be proven by quantum chemical calculations.