Synthesis, structure and catalytic activity of ruthenium diaminodiphosphine complexes
作者:Wai-Kwok Wong、Xiao-Ping Chen、Jian-Ping Guo、Yong-Gui Chi、Wei-Xiong Pan、Wai-Yeung Wong
DOI:10.1039/b106997g
日期:2002.3.8
The reaction of N,N′-bis[o-(diphenylphosphino)benzylidene]-1,2-diaminoethane (L2) with one equivalent of RuCl2(PPh3)3 in dichloromethane at room temperature gave trans-RuCl2(PPh3)(κ3-L2) 2 in high yield. When refluxed in toluene in air, 2 was converted quantitatively to trans-RuCl2(κ4-L2) 3. When treated with one equivalent of hydrogen peroxide in chloroform, 2 was oxidized to trans-RuCl2(PPh3)(κ3-L3) 4, in which the pendant phosphine has been oxidized to a phosphine oxide. Complex 4 can be further
oxidized with another equivalent of hydrogen peroxide to trans-RuCl2(PPh3)(κ3-L4) 5, in which the amino group trans to PPh3 has been oxidized to an imino group. When treated with excess hydrogen peroxide in ethanol, 3 was oxidized to trans-RuCl2(κ4-L5) 6, in which the diamino moiety [–N(H)CH2CH2N(H)–] has been oxidized to a conjugated diimino moiety (–NCHCHN–). The solid-state structures of 2, 4, 5 and 6 were ascertained by X-ray crystallography. Catalytic studies show that 2
is an effective catalyst for the oxidation of alkanes, alkenes and alcohols with air or tert-butyl hydroperoxide. Experimental evidence suggests that free radicals are probably involved in the catalytic oxidation processes.
N,N'-双[邻-(二苯基膦)亚苄基]-1,2-二氨基乙烷(L2)与一当量RuCl2(PPh3)3在二氯甲烷中室温反应得到反式-RuCl2(PPh3)(κ3- L2) 2 产量高。当在空气中的甲苯中回流时,2被定量转化为反式-RuCl2(κ4-L2) 3。当用一当量的过氧化氢的氯仿溶液处理时,2被氧化为反式-RuCl2(PPh3)(κ3-L3) 4,其中侧链膦已被氧化成氧化膦。复合物4可以进一步
用另一当量的过氧化氢氧化为反式-RuCl2(PPh3)(κ3-L4) 5,其中反式至PPh3的氨基已被氧化为亚氨基。当用乙醇中的过量过氧化氢处理时,3 被氧化为反式-RuCl2(κ4-L5) 6,其中二氨基部分 [–N(H)CH2CH2N(H)–] 已被氧化为共轭二亚氨基部分 (– NCHCHN–)。通过X射线晶体学确定了2、4、5和6的固态结构。催化研究表明 2
是一种有效的催化剂,用于空气或氢过氧化叔丁基氧化烷烃、烯烃和醇。实验证据表明自由基可能参与催化氧化过程。