crystallographic analysis revealed that the Ru−Ccarbene distances (1.938(5)−1.984(4) Å) measured in the DAC-supported complexes were relatively short, particularly in comparison to the range of Ru−Ccarbene distances typically observed in analogous N-heterocyclic carbene (NHC) supported complexes (1.96−2.03 Å). While the Tolman electronic parameters (TEP) of various DACs (2056−2057 cm−1) were calculated to
合成并研究了一系列含N,N'-二
叠氮碳烯(
DACs)的Ru基烯烃复分解催化剂。X射线晶体学分析表明,在
DAC负载的配合物中测得的Ru-C卡宾距离(1.938(5)-1.984(4)Å)相对较短,特别是与通常观察到的Ru-C卡宾距离的范围相比在类似的N-杂环卡宾(NHC)负载的配合物中(1.96-2.03Å)。尽管各种
DAC(2056-2057 cm -1)的Tolman电子参数(
TEP)与PCy 3(2056 cm -1)相似),由
DAC支持的Ru配合物促进的
二乙基丙二酸二乙酯的闭环复分解(RCM)进行的速度相对较慢。然而,与含膦的配合物不同,
DAC类似物将二甲基烯
丙二酸二乙酯的RCM催化成其各自的四取代的烯烃。一系列电
化学实验表明,带有
DAC配体的Ru络合物比包含膦和各种N-杂环卡宾(NHCs)的类似络合物(包括四氢
嘧啶二亚烷基,饱和的和饱和的)在较高的电势下(ΔE pa > 0.5 V