Gold(I) Complexes Bearing Sterically Imposing, Saturated Six- and Seven-Membered Expanded Ring N-Heterocyclic Carbene Ligands

The synthesis and characterization of novel six- and seven-membered expanded ring N-heterocyclic carbene (NHC) complexes of the general formula [Au­(NHC)­Cl] are described. The key structural parameters of complexes 1, 2, and 4 have been evaluated by solid-state analysis and by means of the percent buried volume (%Vbur) analysis. Complex 4 is found to demonstrate the largest %Vbur value of any gold­(I) NHC complex reported to date, with a value of 52.6. All complexes 1–4 have been evaluated in a preliminary catalytic survey of the hydration of internal alkynes.本工作报道了通式为[Au(NHC)Cl]的新型六元、七元扩环氮杂环卡宾（N-heterocyclic carbene, NHC）金(Ⅰ)配合物的合成与表征。通过固态结构分析及空间掩埋体积百分比（percent buried volume, %Vbur）分析手段，对配合物1、2及4的关键结构参数进行了评估。研究发现，配合物4是迄今为止已报道的所有金(Ⅰ) NHC配合物中空间掩埋体积百分比最高的体系，其数值达52.6。所有配合物1至4均参与了内炔水合反应的初步催化性能考察。