Design,Synthesis And Properties Of Novel Conjugated Macrocycles Based On Carbon Nanotube Fragments

Carbon nanotube segment-based macrocycles are a new type of organic conjugated molecules.Because of their interesting conjugated ring structure,infinitely conjugated n system and unusual photoelectricity,they have attracted extensive attention from researchers.By changing the conjugation degree and size or introducing different building units and functional groups,the electronic structure of conjugated macrocycles can be adjusted,and then different photoelectric properties can be given.The design and synthesis of well-defined organic conjugated macrocycles has become one of the most important goals in materials,chemistry and physical science.In recent years,many new types of organic conjugated macrocycles have been born in the hands of scientists.In this paper,we studied the photophysical and chiral properties of the conjugated macrocyclic molecules based on different aryl building units by organic synthesis.The details are as follows:(1)Two conjugated macrocycles[3]cyclo-1,8-pyrenes were designed and synthesized by[4+2]cycloaddition reaction from planar pyrenylarylene-ethynylene macrocycles,which can be regarded as the fragment models of single-walled carbon nanotubes.Then,a series of physical characterization methods(1H NMR and 13C NMR spectroscopy,high-resolution mass spectrometry,single crystal X-ray diffraction,UV-Vis absorption spectra and fluorescence spectroscopy,etc.)were used to fully characterize the structure and photophysical properties of the target molecule.The conjugation degree of ring molecules will be reduced when they change from planar structure to curved structure,which shows obvious blue shift phenomenon.The results of variable temperature NMR show that the configuration of this kind of macrocycles has good stability.(2)We constructed a conjugated macrocycle with inherent chirality from an achiral small planar fused ring molecule through a simple Suzuki-Miyaura coupling reaction.We successfully resolved the two chiral isomers by HPLC.The CD spectra and CPL spectra showed that the two isomers had obvious enantiomeric characteristics.The CD spectra showed mirror image relationship and had obvious Cotton effect.And the gabs of(-)/(+)-[7]CPPRu2,9 were-0.0078 and 0.0077,respectively.UV-Vis absorption spectra and fluorescence spectroscopy of target molecules and small planar fused ring molecules were also tested.