通过使用[4,5]-或[5,6] -pine烯稠合的2,2'-联吡啶单元制备了一系列C 2对称手性四齿配体,这些单元被刚性的亚芳基-乙炔骨架支撑。这些构象预先组织的螯合物支持稳定的1:1金属络合物,其特征在于UV / Vis,荧光,圆二色性(CD)和1 H NMR光谱。仔细检查激子耦合圆二色性(ECCD)和1然而,反应混合物在溶液中的1 H NMR谱图揭示了中间物种向最终1:1金属-配体加合物途中的演化和衰减。与该模型一致,质谱分析揭示了溶液中以高配体/金属比存在多种金属络合物,这在紫外/可见光谱或荧光光谱技术中基本上是无法观察到的。使用双齿模型系统进行的比较研究已完全确定了π共轭配体骨架的功能,从而显着增强了1:1配合物的热力学稳定性。除了用作有用的光谱学句柄,以了解这种金属-配体组装过程原本“不可见”的解决方案动力学,G ≠)在热力学稳定但动力学不稳定(P)和(M)立体异构体之间进行手性切换。
Self assembly of phenyl bridged bisbipyridines with manganese perchlorate gave structurally different metallo-macrocycles having cis-labile coordination sites which can catalyse olefin epoxidation with peracetic acid in good yield.
Abstract A ΛΛΛΛ-M4L6 tetrahedral manganese cage with a captured perchlorate or trifluoromethanesulfonate anion was synthesized using a chiral quaterpyridine; the captured anion is exchangeable and the removal of the captured ClO4− from the cage was studied by theoretical calculation.