Design and synthesis of shape-persistent arylene-ethynylene covalent organic polyhedrons through alkyne metathesis and their fullerene-binding study

Shape persistent 2-D macrocycles constructed via alkyne metathesis have been well explored in the past decade. However, 3-D Covalent Organic Polyhedrons (COPs) synthesized through alkyne metathesis have been rarely studied. The objective of the work described in this thesis is to explore the efficient assembly of 3-D shape-persistent covalent organic polyhedrons through dynamic alkyne metathesis and study the relationship of the COP structures and the geometry of their building blocks. The applications COPs in host-guest chemistry, specifically the interactions with fullerenes will be discussed.;In Chapter 1, an overview of the current advances in alkyne metathesis reactions and their application in organic materials development, including design and synthesis of novel polymers, shape-persistent 2-D macrocycles, 3-D molecular cages and porous frameworks.;In Chapter 2, the design and synthesis of a tetrameric COP with an unexpected D2h symmetry through one-step alkyne metathesis from a C3 symmetrical monomer is discussed. The COP structure was confirmed by the signal crystal X-ray diffraction. This COP exhibits high binding affinity with C70 over C60 (K C70/KC60 > 1000).;In Chapter 3, the synthesis of a dumbbell-shape tetrameric COP through alkyne metathesis is discussed. The formation of the tetrameric structure instead of entropically- favored dimeric one is investigated through computer modelling study. The cage also serves as a host for fullerenes.;In Chapter 4, the relationship between cage structures and the geometry of monomers in the dynamic assembly process is discussed. A dimeric cage and its interlocked cages were obtained in one-pot alkyne metathesis starting from an extend C3 symmetry monomer.;In Chapter 5, the design and synthesis of a series of pyrene based COPs are described. These COPs exhibit strong fluorescence and significant binding affinity with fullerenes. They can be transferred into cells, which have potential applications in diagnosis. A water soluble pyrene cage was also synthesized and its biological property study is undergoing.