Bridged dinucleating N-heterocyclic carbene ligands and their double helical mercury(II) complexes

详细信息	查看全文 | 推荐本文 |

• 作者：Ulrich Jü ; rgen Scheele ; Sebastian Dechert ; Franc Meyer
• 关键词：N-heterocyclic carbene (NHC) ; Mercury ; Double helicates ; Bimetallic complexes ; N-ligands
• 刊名：Inorganica Chimica Acta
• 出版年：2006
• 期刊代码：40_00201693
• 类别：ch
• 出版时间：1 December 2006
• 卷：359
• 期：15
• 页码：4891-4900
• 文件大小：463 K

摘要

A series of six 3,6-bis(imidazolium-3-yl)pyridazine derivatives with different imidazole-N substituents have been synthesized and isolated as the salts [H₂L]Cl₂ (1a)–(6a) and [H₂L](PF₆)₂ (1b)–(6b). Solid state structures have been determined crystallographically for eleven out of the twelve compounds, revealing diverse hydrogen bonding patterns that involve the imidazolium-C²H units and the anions. N-heterocyclic carbene (NHC) mercury(II) complexes [Hg₂L₂](PF₆)₄ (7)–(9) are readily formed in good yields from ligand precursors [H₂L](PF₆)₂ and Hg(OAc)₂, as long as imidazole-N substituents are not too bulky. X-ray crystallography reveals double helical bimetallic arrangements for the stable [Hg₂L₂]⁴⁺ cations. Ligand scrambling in [Hg₂L₂]⁴⁺ occurs only in the presence of free carbene precursor, presumably via an associative mechanism.