much greater temperatures. Analogs with halides other than chloride (Br, I), or with pseudo-halides (OCN, N3), are found to exhibit generally similar behavior: high catalytic activity under H2 and measurable but much lower activity in the absence of H2. Thermolysis (under argon) of complexes [RhL2Cl]n (n = 1, 2; L is a phosphine bulkier than PMe3) in cyclooctane in the absence of hydrogen acceptors yielded
以前已报道过Rh(PMe 3)2 ClL'(L'= CO或三取代的膦)和[Rh(PMe 3)2 Cl] 2形式的配合物可使用烯烃氢受体在二
氢气氛。据报道,在没有H 2的情况下,即使在更高的温度下,这种配合物也能实现转移-脱氢,但速率和总催化转化率要低得多。发现与
氯化物以外的卤化物(Br,I)或假卤化物(OCN,N 3)的类似物表现出大致相似的行为:在H 2下具有高催化活性和在没有H 2的情况下可测量但活性低得多。在不存在氢受体的情况下,在
环辛烷中热解(在
氩气下)配合物[RhL 2 Cl] n(n = 1,2; L是比PMe 3更大的膦),生成环
辛烯。然而,转移-脱氢受到
配体分解的困扰。在
氢气氛下,含有比PMe 3体积大得多的
配体的络合物不影响脱氢作用。具有三齿
配体的络合物,(η 3 -PXP)RHL'(PXP =(ME 2 PCH 2我2 Si)的2 N,我2 PCH 2(2,6-C 6 H