governed by the steric requirements of both the chelating phosphine ligand and the diene. In some cases, mononuclear methyl substituted allyl complexes are produced either as side products, or as the major products. The binuclear compounds may alternatively be synthesized via reaction between the chlorobridged dimers [R2P(CH2)nPR2Rh]2(μ-C1)2 (n = 2,3; R = Przi) and magnesium diene reagents; indeed this
式[R 2 P(CH 2)n PR 2 } Rh] 2(μ-H)2(1a:n = 2,R = Pr i ; 1b:ñ = 3,R = PR我)被发现与烯烃和二烯
化学计量反应。对烯烃的反应性受辅助双
膦配体的空间性质影响。化合物1a与多种简单的烯烃反应,生成式[(dippe)Rh] 2(μ-η )的双核桥联烯基-
氢化物配合物2 -σ-RCCH(R)(μ-H),而1b结合了更大的空间体积的dipp
配体,仅与
乙烯反应。在这些复合物的μ链烯基
配体显示出公知的“风挡刮
水器” fluxionality,具有Δ ģ ‡12.2(2)千卡摩尔-1发现[(dippe)的Rh] 2(μ-η 2 -σ-HC CH 2)(μ-H),2A。这些反应的拟议机制包括用一当量的烯烃对二
氢化物进行脱氢,然后使第二当量的烯烃与瞬态[(P 2)Rh] 2 d 9 - d 9 Rh(O)二聚体反应。二
氢化物1a和1b还与1,