International Research Fellowship Program: Photoswitchable Nanotubes and Nanocapsules Based on Resorcinarene Cavitand Scaffolds

希尔特克利夫国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持Laura D.Shirtcliff博士与瑞士苏黎世ETH的Francois Diederich博士合作为期24个月的研究奖学金。该奖学金期间将完成的研究是形成胶囊系统的分子化学的一个新颖和独特的扩展。这些分子胶囊本身要么太容易解离和随后的客体去除，要么根本不允许客体去除，除非在强制条件下。引入允许受调控的客体关联/解离的基序引入了一种控制分子的独特方法。在广泛的初步模型研究之后，将采用一条优雅的合成路线来制备具有不同扰动模式的纳米管和纳米胶囊。其目的是将可光切换的成分加入到新型间苯二酚[4]芳烃空穴中。外界对光的刺激、pH的变化或温度的变化都会改变可切换的纳米管或胶囊，并改变它们与其他分子的结合能力；单一的相互作用就能导致结构的整体重组。此外，这种控制可用于分子传输，选择性地从其腔中摄取/释放客体。当暴露在适当的刺激下时，可切换的纳米管和纳米胶囊有望经历显著的几何相互转化，这些转化是可逆的和可重复的。这些新型的光响应受体/开关将被研究其形状依赖的主客体络合行为，具有光学读出能力的客体传感，以及它们作为新的读写存储器件的潜力。

0601996ShirtcliffThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Laura D. Shirtcliff to work with Dr. Francois Diederich at ETH in Zurich, Switzerland.The research to be completed during the fellowship is a novel and unique extension of the chemistry of molecules that form capsular systems. These molecular capsules have inherently suffered from either too facile of dissociation and subsequent guest removal or from not permitting for guest removal at all unless under forcing conditions. Incorporation of motifs that allow for regulated guest association/dissociation introduces a unique method of control over the molecules. Following extensive preliminary model studies, an elegant synthetic route will be undertaken to prepare nanotubes and nanocapsules that have different mode of perturbing their geometry. The objective is to incorporate light-switchable components into novel resorcin[4]arene cavitands. External stimulation either with light, a change in pH, or a change in temperature transforms the switchable nanotubes or capsules and transmutes their ability to associate with other molecules; a single interaction can cause a global reorganization of structure. In addition, this control can be utilized for molecular transport with selective uptake/release of a guest from its cavity. The switchable nanotubes and nanocapsules are expected to undergo marked geometric inter-conversions that are reversible and repeatable, when exposed to the appropriate stimuli. These novel photoresponsive receptors/switches will be investigated for their shape-dependant host-guest complexation behavior, for guest sensing with the capability of optical readout, and for their potential as new read-write memory devices.