[(C5H4−CR1R2−PAr2)2Zr−Cl+] (5), with both phosphanyl groups internally coordinated to the metal centre. Three possible diastereoisomers are observed in the case of 5c (R1 = H; R2 = CH3), while bulkier R2 substituents give higher selectivities. The thermally induced (reversible) cleavage of the Zr−phosphane linkage results in dynamic NMR behaviour. Gibbs activation energies of ΔG≠(298 K) = 14.8 ± 0.5 and 14.5
用 Li[B(
C6F5)4 处理取代的(二芳基膦酰基)甲基-4 茂
金属配合物 [(
C5H4-CR1R2-PAr2)2ZrCl2](2:R1/R2 =
CH3/ 、H/ 、H/芳基) ] 在
二氯甲烷溶液中导致
氯化物
配体提取(LiCl 沉淀)以产生复合物 [( −CR1R2−PAr2)2Zr−Cl+] (5),两个
磷酰基在内部与
金属中心配位。在 5c 的情况下观察到三种可能的非对映异构体(R1 = H;R2 = ),而较大的 R2 取代基提供更高的选择性。Zr-
磷烷键的热诱导(可逆)裂解导致动态 NMR 行为。对于这些复合物 trans-5d (R1 = H; R2 = Ph) 和 trans-5e (R1 =) 中的分子内平衡过程,获得了 ΔG≠(298 K) = 14.8 ± 0.5 和 14.5 ± 0.5 kcal/mol 的吉布斯活化能H;R2 =
二茂铁),分别。用