Xe@cryptophane Complexes with C2 Symmetry: Synthesis and Investigations by 129Xe NMR of the Consequences of the Size of the Host Cavity for Xenon Encapsulation
作者:Thierry Brotin、Jean-Pierre Dutasta
DOI:10.1002/ejoc.200390153
日期:2003.3
at 278 K) than that observed with cryptophane-A (K = 3900 M−1). The free and bound guests were observed at room temperature under slow-exchange conditions on the 129Xe NMR timescale. A linear relationship was observed between the binding constants and the internal volume of the hosts. Under the same conditions, the Xe@cryptophane-224 [Xe3] complex underwent a fast-exchange process on the NMR timescale
新的cryptophanes-223 (1)、-233 (2) 和-224 (3) 具有C2 对称性,带有连接两个环三戊四烯单元的不同接头,是按照多步程序合成的。通过 129Xe NMR 光谱研究了氙@cryptophane 配合物的形成。Cryptophanes-223 (1) 和 -233 (2) 在 1,1,2,2-[D2] 四氯乙烷溶液中有效地复合氙气,结合常数稍低(K 在 278 K 时分别为 2810 M-1 和 810 M-1) ) 比用cryptophane-A (K = 3900 M-1) 观察到的。在 129Xe NMR 时间尺度上的缓慢交换条件下,在室温下观察游离和结合客体。在结合常数和宿主的内部体积之间观察到线性关系。在同等条件下,Xe@cryptophane-224 [Xe3] 复合物在 NMR 时间尺度上经历了快速交换过程。解络合活化能 Ea 以及相关参数 ΔH‡