Metallation of the isopropenyl group by platinum(<scp>II</scp>): mechanism of formation of isomeric σ-allylic and σ-vinylic six-membered chelate rings. X-Ray structure of the σ-vinylic complex di-µ-acetato-bis-{[2-(o-diphenylarsinophenyl)propenyl–C′As]platinum(<scp>II</scp>)}
作者:Mervyn K. Cooper、Philip J. Guerney、Hilary J. Goodwin、Mary McPartlin
DOI:10.1039/dt9820000757
日期:——
olefin bonded as a σ-vinyl group. Crystals are monoclinic, space group C2/c, a= 31.633(5), b= 11.345(5), c= 18.450(5)Å, β= 141.37(2)°, U= 4 133.6 Å3, Z= 4, and R= 0.059 for 2 093 reflections. The σ-allylic complex (1) is converted to the σ-vinylic complex (2) by acetic acid. Mechanisms for the formation, protonation, and interconversion of the two isomeric forms of the metallated olefin have been deduced;
(o-异丙烯基苯基)二苯基ar(ipa)络合物[Pt(ipa)(acac)] [BF 4 ](acac =乙酰丙酮酸酯)与包括乙酸盐在内的亲核试剂反应,生成[[graphic graph省略] sPh 2 }(acac)](1 ),其中配体作为σ-烯丙基键合。配合物[PtCl 2(ipa)]与乙酸银反应,得到配合物[[省略图示] sPh 2 } 2(µ-O 2 CMe)2 ](2)(通过X射线分析显示)具有去质子化的烯烃键合为σ-乙烯基。晶体是单斜晶体,空间群C 2 / c,a = 31.633(5),b = 11.345(5),Ç = 18.450(5),β= 141.37(2)°,û = 4 133.6埃3,Ž = 4,和- [R 2层093的反射= 0.059。σ-烯丙基络合物(1)被乙酸转化为σ-乙烯基络合物(2)。已经推导了金属化烯烃的两种异构形式的形成,质子化和相互转化的机理