科研之友
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摘要
The ability to control and direct molecular assembly has important implications in the design of environmentally responsive materials. Reported here is the use of competitive neutral- and anionic-guest recognition to control the formation, disruption, replacement-based construction and higher-order assembly properties of pseudorotaxane structures involving a large, cationic tetraimidazolium receptor. In particular, we showed that the chloride anion (as the tetrabutylammonium (TBA ) salt) serves to replace directly the 2,6-naphthalene dicarboxylate dianion from the preformed complex, involving this dianion. In contrast, the addition of the nitrate anion (as the TBA salt) serves to effect displacement of a pre-bound 2,6-naphthalene dicarboxylate dianion in a stepwise manner allowing for stabilization of a so-called outside-binding mode under appropriate conditions. We have also found that by using biphenyl-3,4,3',4'-tetraamine as the guest, a 1D-donoracceptordonor coordination polymer can be stabilized, whereas the addition of 6-amino-naphthalene-2-sulfonate anion to the pre-formed complex between the tetraimidazolium receptor and the 2,6-naphthalene dicarboxylate dianion produces a new pseudorotaxane complex. This guest-based competition and subsequent molecular translocation is supported by solution-state NMR spectroscopic studies as well as solid-state single-crystal X-ray structural analyses. The results described herein provide initial evidence that guest competition can be used to control molecular switching and substrate binding within an appropriately designed anion receptor.
- 出版日期2012-6
- 单位中国人民大学
