A facile synthetic access to the homologous series of 1,1â²-ferrocenylene bisdihalophosphanes Fcâ²(PX2)2 (X = F, Cl, Br, I; Fcâ² = 1,1â²-ferrocenediyl = ferrocenylene = âC5H4FeC5H4â) is reported. The 31P NMR spectroscopic data of this series suggest a similar electronic interaction of the âPX2 unit with the ferrocene system as in monofunctional ferrocenyldihalophosphanes. Crystal structures for Fcâ²(PCl2)2 and Fcâ²(PBr2)2 reveal that the nature of the halogen atom within the phosphane unit strongly influences the twist angle of the ferrocene system, while leaving the other structural parameters mostly unaffected. Based on these bisdihalophosphanes, a synthetic access to the first metallocene bridged bisphosphaalkene ((C5H4PC(t-Bu)OTMS)2Fe) is reported in which the tert-butyl substituents provide sufficient steric pressure to control the E/Z isomeric ratio which leads to the almost exclusive formation of the most stable Z,Z isomer out of the three possible isomers.
报告了一种简便的合成方法,以获取1,1'-
铁烯基二卤膦Fc²(PX2)2(X = F, Cl, Br, I; Fc² = 1,1'-
铁烯基 =
铁烯烃 = - Fe -)的同系物系列。该系列的31P NMR光谱数据表明,-PX2单元与
铁烯基系统之间存在与单功能
铁烯基二卤膦相似的电子相互作用。Fc²(PCl2)2和Fc²(PBr2)2的晶体结构揭示,膦中卤素原子的性质对
铁烯基系统的扭转角度有显著影响,而对其他结构参数影响较小。基于这些二卤膦,报告了一种合成首个
金属烯桥接的
双膦烯((
C5H4PC(t-Bu)OTMS)2Fe)的方法,其中叔丁基取代基提供了足够的空间压力来调控E/Z异构比,从而几乎独占性地形成最稳定的Z,Z异构体。