| Summary: | 博士 === 國立交通大學 === 應用化學系所 === 95 === There are two parts in this thesis: part 1, regio selectivity in the 1,3-dipolar cycloaddition of adamantylidenefulvene and its modification by inclusion in cyclodextrins’ solutions, part 2, syntheses of ditopic fluorescent receptors using calix[4]arenes.
In part 1, the 1,3-dipolar cycloaddition of adamantylidenefulvene (51) with nitrile oxides 52a-d led to complex product distribution. We isolated 1:1 cycloadduct 53 and 54a-d as major products and 1:2 cycloadducts 55, 56, 57a-d, and 58b as minor products. The stereochemistry of all products was characterized by 1D and 2D NMR spectroscopy. The 1,3-dipolar cycloaddition of adamantylidenefulvene (51) with nitrile oxides 52a-d was further carried out in beta-CD solution. We found that product ratio of 53a/54a was enhanced to 71/29 in the presence of beta-CD compared to that of 40/60 in the absence of beta-CD. Moreover, the product ratio of 53a/54a was highly enhanced to 99/1 when aryl group of the nitrile oxide is 4-t-butylphenyl. Molecular dynamic (MD) simulations were carried out to provide information of the complexation modes of 51•beta-CD, 53a•beta-CD, 54a•beta-CD, 59a•beta-CD and 59b•beta-CD. It was found that both steric and electrostatic effects play important roles in determining the regio- and stereochemistry of 1,3-dipolar cycloaddition of 51.
In part 2, the synthesis of fluorescent calix[4]arenas 98a-c, 99a-b and their application in ditopic recognitions were studied. Based on the metal screening of 98a-c, we found that 98a-c showed selective recognition of Cu2+ among 14 metal ions. Interestingly, during the complexation of Cu2+ by 98a-c, an autoreduction of Cu2+ to Cu+ occurred. The ring-opening compound 99a showed selective recognition toward Hg2+ and Cu2+ ions, but no obvious complexation for anions. Furthermore, compound 99b was found as a fluorescent-enhanced sensor for Hg2+ ion. Finally, we studied the allosteric effect of complex 99a•Hg2+ with anions using UV-vis spectroscopy and found that showed a selective recognition of AcO- and I- ions.
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