Kinetische und mechanistische untersuchungen von übergangsmetall-komplex-reaktionen
作者:Helmut Fischer
DOI:10.1016/0022-328x(88)80235-3
日期:1988.5
The pentacarbonyl(thioaldehyde), -(selenoaldehyde), and -(selenoketone)complexes (CO)5M[XC(Ph)R] (I) (M = Cr, X = Se, R = Ph; M = W, X = S, R = H; M = W, X = Se, R = H, Ph, C6H4Br-p, C6H4Me-p, C6H4NMe2-p react with dienes such as cyclopentadiene, trans-1-methyl-1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-cyclohexadiene via [4 + 2]-cycloaddition to give metal-coordinated
五羰基(
硫醛),-(
硒醛)和-(
硒酮)配合物(CO)5 M [XC(Ph)R](I)(M = Cr,X = Se,R = Ph; M = W ,X = S,R = H; M = W,X = Se,R = H,Ph,C 6 H 4 Br- p,C 6 H 4 Me- p,C 6 H 4 NMe 2 - p与二烯反应如
环戊二烯,反式-1-甲基-
1,3-丁二烯,2-甲基-
1,3-丁二烯,
2,3-二甲基-1,3-丁二烯和
1,3-环己二烯通过[4 + 2] -环加成反应生成
金属配位的
噻吩和
硒杂环,反应遵循二级动力学:-d [I] / d t = k2 [I]·[diene]。活化焓ΔH ≠小(46至28.7 kJ / mol),并沿着亚
硒酮,
硫醛,
硒醛复合物系列降低。活化熵ΔS ≠强负值(-144至-147 J /(mol K),与络合物类型无关。与
环戊二烯反应的速率常数k 2随(Y)中Y的给体容量增加而明显降低。