Carbamate triserine lactone receptors for anion recognition

摘要

Anion recognition, and it's binding and transport, is now a major field of molecular recognition chemistry because of its importance in biochemistry, medicine, pharmacy, analytical chemistry, and catalysis. An important development is preorganized tripodal receptors with hydrogen binding sites. Enterobactin, a siderophore produced by enteric bacteria, binds ferric ion exceptionally well (Kf= 1049) and is composed of a tri-L-serine lactone platform that is appended 2,3-dihydroxybenzoyl groups. It has been shown that enterobactin's ability to sequester iron so effectively is due in good measure to the conformation of the trilactone that preorganizes the binding groups for metal ion binding. As an extension of the preorganization concept, this thesis will describe the preparation of carbamate triserine lactone receptors, their characterization using both spectroscopy and molecular modeling, and their ability to act as molecular receptors to anions. By using a 1H NMR titration method, the receptors bind halides with the following general order of selectivity: F->Cl->Br ->I-, with associate constant Kalpha in the range 5-7130 M-1.