Synthesis, neutron structure, and reactivity of the bis(dihydrogen) complex RuH2(η2-H2)2(PCyp3)2 stabilized by two tricyclopentylphosphines
Synthesis, neutron structure, and reactivity of the bis(dihydrogen) complex RuH2(η2-H2)2(PCyp3)2 stabilized by two tricyclopentylphosphines
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DOI：
10.1021/ja055126g
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发表时间：
2005-12-21
影响因子：
15
通讯作者：
Sabo-Etienne, S
中科院分区：
文献类型：
--
作者：
Grellier, M;Vendier, L;Sabo-Etienne, S
钌（η - 4- c8h12）（η - 6- c8h10）在2等量的三环戊基膦（PCyp3）存在下用3 bar H2in在戊烷中处理，分离得到新的双氢配合物RuH2(η - 2- h2)2(PCyp3)2(2)，用NMR、单晶x射线和中子衍射对其进行了表征。单晶中子衍射研究是首次对二氢配合物进行的。金属中心周围的配位几何是一个扭曲的八面体，由两个反式（成168.9(1)°角）的磷化氢、两个顺式二氢配体和两个反式的氢化物定义为赤道面。H - H键距离(0.825（8)和0.835(8)Å）是两种“未拉伸”二氢配体的特征。氘化苯的Ru - H和C - D键在1 H内发生H/D交换，生成不同的同位素体RuHxD6-x(PCyp3)2（x= 0 ~ 6）。2是乙烯偶联（20bar, 293 K）到功能化芳烃（Murai反应）的催化剂前驱体。我们发现苯乙酮在35分钟内转化为2-乙基苯乙酮，而在相同的条件下，使用类似的三环己基膦配合物，RuH2(η - 2- h2)2(PCy3)2，最好的催化剂前驱体，在室温下需要10小时。
Treatment of Ru(η4-C8H12)(η6-C8H10) with 3 bar H2in the presence of 2 equiv of tricyclopentylphosphine (PCyp3) in pentane resulted in the isolation of the new bis(dihydrogen) complex RuH2(η2-H2)2(PCyp3)2(2), characterized by NMR and single-crystal X-ray and neutron diffraction. The single-crystal neutron diffraction study is the first carried out for a bis(dihydrogen) complex. The coordination geometry around the metal center is a distorted octahedron defined by the two phosphines in a trans configuration (making an angle of 168.9(1)°), two cis dihydrogen ligands, and two hydrides trans to them, defining the equatorial plane. The H−H bond distances (0.825(8) and 0.835(8) Å) are characteristic of two “unstretched” dihydrogen ligands. H/D exchange between the Ru−H and the C−D bonds of deuterated benzene is observed within 1 h, leading to the formation of various isotopomers RuHxD6-x(PCyp3)2(withx= 0−6).2is a catalyst precursor for ethylene coupling (20 bar, 293 K) to a functionalized arene (Murai reaction). We found a 90% conversion of acetophenone to 2-ethylacetophenone within 35 min, whereas 10 h was needed in the same conditions using the analogous tricyclohexylphosphine complex, RuH2(η2-H2)2(PCy3)2, the best catalyst precursor,at room temperature, prior to this work.