Department of Chemistry, Tulane University, New Orleans, Louisiana 70115, USA.
J Am Chem Soc. 2013 Mar 20;135(11):4314-24. doi: 10.1021/ja310741q. Epub 2013 Mar 12.
Two hosts that utilize the hydrophobic effect to assemble and/or encapsulate guest molecules were studied. The hosts, octa-acid (OA) and hexalene diamine-linked octa-acid (HOA), were shown to complex a broad range of n-alkanes up to n-hexacosane (C26H54). A combination of (1)H NMR, NMR diffusion, COSY, and NOESY experiments revealed four different guest packing motifs, depending on the size of the guest and the nature of the host. As a function of guest size, smooth transitions from one motif to the next were observed and allowed qualification of their relative stabilities. Furthermore, although the two hosts engender ostensibly identical encapsulation environments, their different assembly properties lead to quite distinct packing-motif profiles, i.e., how the motifs change as a function of guest size.
研究了两种利用疏水作用组装和/或封装客体分子的主体。主体化合物为八羧酸（OA）和六亚甲基二胺连接的八羧酸（HOA），它们能够络合广泛范围的正烷烃，直到正二十六烷（C26H54）。通过（1）H NMR、NMR 扩散、COSY 和 NOESY 实验的组合，根据客体的大小和主体的性质，揭示了四种不同的客体包装模式。作为客体大小的函数，观察到从一种模式到另一种模式的平稳转变，并确定了它们的相对稳定性。此外，尽管这两个主体产生了表面上相同的封装环境，但它们不同的组装性质导致了截然不同的包装模式谱，即模式如何随客体大小而变化。
