title: A tetrameric cage with D2h symmetry through alkyne metathesis.
abstract: Shape-persistent covalent organic polyhedrons (COPs) with ethynylene linkers are usually prepared through kinetically controlled cross-coupling reactions. The high-yielding synthesis of ethynylene-linked rigid tetrameric cages via one-step alkyne metathesis from readily accessible triyne precursors is presented. The tetrameric cage contains two macrocyclic panels and exhibits D2h symmetry. The assembly of such a COP is a thermodynamically controlled process, which involves the initial formation of macrocycles as key intermediates followed by the connection of two macrocycles with ethynylene linkages. With a large internal cavity, the cage exhibits a high binding selectivity toward C70 (K = 3.9×10(3) L mol(-1)) over C60 (no noticeable binding).
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309 (USA) http://chem.colorado.edu/zhanggroup.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Chenxi
authors.initials: C
authors.lastname: Zhang
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Noll
authors.forename: Hai
authors.initials: H
authors.lastname: Long
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Jin
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
keywords: alkyne metathesis; dynamic covalent assembly; fullerene receptors; organic molecular cages; thermodynamic control