Crystal Structures of [PhLi·(−)-sparteine]₂, [PhOLi·(−)-sparteine]₂, and the Mixed Aggregate [PhLi·PhOLi·2(−)-sparteine]

Crystal structure determination of adducts of (−)-sparteine and PhLi, (−)-sparteine and PhOLi and of (−)-sparteine and PhLi/PhOLi reveal a four-membered ring with two lithium centers, each capped by a (−)-sparteine ligand, as central motif of all structure. Quantum-chemical calculations show that the mixed aggregate [PhLi·PhOLi·2(−)-sparteine] is energetically more favorable than the model system {1/2[PhLi·(−)-sparteine]2 + 1/2[PhOLi·(−)-sparteine]2}.对(-)-金雀花碱（(-)-sparteine）与苯基锂（PhLi）、(-)-金雀花碱与苯氧基锂（PhOLi），以及(-)-金雀花碱与PhLi/PhOLi混合体系所形成加合物的晶体结构测定结果显示，所有目标结构的核心基元均为含两个锂中心的四元环，且每个锂中心均被一个(-)-金雀花碱配体配位包覆。量子化学计算表明，混合聚集体[PhLi·PhOLi·2(-)-sparteine]在能量上较模型体系{1/2[PhLi·(-)-sparteine]₂ + 1/2[PhOLi·(-)-sparteine]₂}更为有利。