Emergence of non-monotonic deep cavity cavitand assembly with increasing portal methylation
Emergence of non-monotonic deep cavity cavitand assembly with increasing portal methylation
复制标题
随着门静脉甲基化的增加，非单调深腔空穴组装体的出现
DOI：
10.1039/c9me00076c
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发表时间：
2020
影响因子：
3.6
通讯作者：
Ashbaugh, Henry S.
中科院分区：
文献类型：
--
作者：
Saltzman, Alexander;Tang, Du;Gibb, Bruce C.;Ashbaugh, Henry S.
八羧酸（OA）和四内甲基八羧酸（TEMOA）是深腔空化体，在水溶液中容易与疏水客体（如正构烷烃）形成多聚物配合物。实验结果表明，在相同的客体尺寸范围内，OA表现出从单体到二聚体的单调发展，正构烷烃的长度不断增加，而TEMOA则表现出从单体到二聚体，再到单体，再到二聚体的非单调发展。在此之前，我们已经进行了模拟，证明了这种奇怪的行为是由于甲基单元包围了TEMOA的疏水口袋入口，阻止了在二聚体中两个宿主之间同时桥接两个烷烃链的可能性。在这里，我们扩展了之前的模拟研究，考虑了部分甲基化的宿主单内酯甲基八酸、1,3-二内酯甲基八酸和三内酯甲基八酸，以研究非单调组装行为的出现。我们的模拟表明，随着门脉甲基化的增加，非单调组装的系统进展。这种行为可以追溯到2:2复合物（两个主人与两个客人聚集）的逐渐不稳定，而不是稳定其他可能形成的潜在主人/客人复合物。
Octa-acid (OA) and tetra-endo-methyl octa-acid (TEMOA) are deep cavity cavitands that readily form multimeric complexes with hydrophobic guests, like n-alkanes, in aqueous solution. Experimentally, OA displays a monotonic progression from monomeric to dimeric complexes with n-alkanes of increasing length, while TEMOA exhibits a non-monotonic progression from monomeric, to dimeric, to monomeric, to dimeric complexes over the same range of guest sizes. Previously we have conducted simulations demonstrating this curious behavior arises from the methyl units ringing TEMOA's portal to its hydrophobic pocket barring the possibility for two alkane chains to simultaneously bridge between two hosts in a dimer. Here we expand our prior simulation study to consider the partially methylated hosts mono-endo-methyl octa-acid, 1,3-di-endo-methyl octa-acid, and tri-endo-methyl octa-acid to examine the emergence of non-monotonic assembly behavior. Our simulations demonstrate a systematic progression of non-monotonic assembly with increasing portal methylation. This behavior is traced to the progressive destabilization of 2 : 2 complexes (two hosts assembled with two guests) rather than stabilizing other potential host/guest complexes that could be formed.
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影响因子：
3.3
作者：
Du Tang;Barnett, J. Wesley;Ashbaugh, Henry S.
通讯作者：
Ashbaugh, Henry S.
影响因子：
16.6
作者：
Tiefenbacher, Konrad;Ajami, Dariush;Rebek, Julius, Jr.
通讯作者：
Rebek, Julius, Jr.
影响因子：
15
作者：
Liu, Simin;Russell, David H.;Zinnel, Nathanael F.;Gibb, Bruce C.
通讯作者：
Gibb, Bruce C.
DOI：
10.1073/pnas.0409005102
发表时间：
2005-05-10
影响因子：
11.1
作者：
Woo, HJ;Roux, B
通讯作者：
Roux, B
影响因子：
3.3
作者：
Ewell, Jeffrey;Gibb, Bruce C.;Rick, Steven W.
通讯作者：
Rick, Steven W.