The Crucial Role of the Diphosphine Heteroatom X in the Stereochemistry and Stabilization of the Substitution-Inert [M(N)(PXP)]<sup>2+</sup> Metal Fragments (M = Tc, Re; PXP = Diphosphine Ligand)
作者:Francesco Tisato、Fiorenzo Refosco、Marina Porchia、Cristina Bolzati、Giuliano Bandoli、Alessandro Dolmella、Adriano Duatti、Alessandra Boschi、Christian M. Jung、Hans-Juergen Pietzsch、Werner Kraus
DOI:10.1021/ic049139r
日期:2004.12.1
stereochemical arrangements, that is, fac,cis, mer,cis, and mer,trans, depending primarily on the nature of the diphosphine heteroatom X. When X = NH, mer,cis-Tc(N)Cl(2)(PNP1), 1, was the only isomer formed. Alternatively, when a tertiary amine nitrogen (X = NR; R = CH(3), CH(2)CH(2)OCH(3)) was introduced in the bridging chain, fac,cis-M(N)Cl(2)(PN(R)P) complexes (M = Tc, 2, 3; M = Re, 8f) were obtained. Isomerization
已发现掺入五元PXP-二膦桥联链中的杂原子X的性质在总体稳定性和含亚硝基[[M(N)(PXP)](2)的立体化学排列中均起主要单元作用+)金属碎片(M = Tc,Re)。因此,通过将PXP配体与不稳定的[Re(N)Cl(4)](-)和Tc(N)Cl(2)(PPh(3))(2)硝化前体在CH(2)Cl(2)中混合/ MeOH混合物中,收集了一系列中性的M(N)Cl(2)(PXP)配合物(M = Tc,1-5; M = Re,8、9)。在产生的扭曲八面体中,PXP采用面或子午配位,并与卤化物配体结合产生三种不同的立体化学排列,即fac,cis,mer,cis和mer,trans,主要取决于二膦的性质。当X = NH时,mer,cis-Tc(N)Cl(2)(PNP1),1是形成的唯一异构体。或者,当在桥接链中引入叔胺氮(X = NR; R = CH(3),CH(2)CH(2)OCH(3))时,fac,cis-M(N)Cl(2