Department of Chemistry, Curtin University, Perth, Australia.
Dalton Trans. 2011 Nov 28;40(44):11960-7. doi: 10.1039/c1dt11233c. Epub 2011 Oct 10.
Two rhenium(I) carbonyl complexes of the type fac-[Re(CO)(3)(N^C)X] where N^C is an N-heterocyclic carbene [3-butyl-1-(2'-pyridyl)benzimidazolin-2-ylidene] and X is either Cl or Br have been synthesised via an in situ method from [Re(CO)(5)X] and a respective benzimidazolium salt. The complexes have been characterised by (1)H and (13)C NMR, infra-red spectroscopy and in the case of the bromo-complex by a single-crystal X-ray diffraction study. The photophysical properties of the complexes have been investigated, revealing similar phosphorescent emission which was attributed to radiative decay from a (3)MLCT state partially mixed with a (3)LLCT state. However, the analysis of excited state lifetime and quantum yield values revealed distinct photophysical behaviour for the two complexes, which was attributed to the more labile nature of the bromo ligand with respect to the chloro one. The explanation was supported by the time-dependent emission profile change in diluted acetonitrile solutions.
两种铼（I）羰基配合物，类型为 fac-[Re(CO)(3)(N^C)X]，其中 N^C 是一种 N-杂环卡宾[3-丁基-1-(2'-吡啶基)苯并咪唑啉-2-亚基]，X 是 Cl 或 Br，通过原位方法从 [Re(CO)(5)X] 和相应的苯并咪唑鎓盐合成。配合物通过 (1)H 和 (13)C NMR、红外光谱进行了表征，对于溴代配合物还通过单晶 X 射线衍射研究进行了表征。研究了配合物的光物理性质，发现类似的磷光发射，归因于从 (3)MLCT 态部分混合的 (3)LLCT 态的辐射衰减。然而，激发态寿命和量子产率值的分析表明，两个配合物具有明显不同的光物理行为，这归因于溴配体相对于氯配体的更不稳定性质。该解释得到了在稀释的乙腈溶液中随时间变化的发射轮廓变化的支持。
