Synthesis And Properties Of Non-planar Conjugated Acridone Derivatives

Since the first fullerenes were prepared by the British chemist Dr.Harold Voter Croto,the American scientists Richard Smalley and Robert Cole in 1985,the structures of these molecules have aroused great research interest of scientists.Non-planar conjugated mole-cules,such as Corannulene,Sumanene,which can be regarded as structural units of fuller-enes,play an important role in the study of properties of fullerene and the design and syn-thesis of novel non-planar molecules.Their synthetic methods provide inspirations for the preparation of fullerene and carbon nanotubes by solution method.Non-planar conjugated molecules have a special spatial structure and unique physical and chemical properties.Af-ter doping with hetero atoms,their physical and chemical properties will be further modified.Therefore,non-planar conjugated molecules have quickly became a hot topic.Based on these considerations,this paper uses acridone,which has good biological activity and pho-toelectric properties,as the initial structure for conjugate extension.We designed and syn-thesized a nitrogen-doped non-planar conjugated boat-shaped molecules bearing two adja-cent pentagon rings.The main research contents are as follows:1.Summarized the research background of non-planar conjugated molecules and acri-dinone derivatives.Introduced the synthesis process,research progress and application pro-spects of some nitrogen-doped non-planar conjugated molecules.Their structure and prop-erties are also briefly described.Several synthetic schemes were proposed for the designed target compound.The synthetic methods were screened and optimized.10,10'-?1,4-phenylene?bis-?2,7-di-tert-butylacridinone?was used as the starting compounds to undergo an six-step reaction process via stepwise bromination and intramolecular C-H activation and the target compound was finally obtained with a total yield of 18%.2.All the new compounds were characterized by ¹H NMR,¹³C NMR,IR,HRMS and single crystal X-ray diffraction.The crystal structure revealed the target molecule is a boat-shaped compound with two fused concave moieties with a depth of 2.55?.The POAV angle analysis revealed that the pyramidal nitrogen atom is crucial in releasing the strain en-ergy of the non-planar molecules.3.The hydrogen atoms of the methylene parts of the unoxidized nanoboat showed split-ting in the ¹H NMR spectra,indicating the slow inversion process of the nanoboat at room temperature.The theoretical calculation unraveled that the inversion process is stepwise with an“S”shaped intermediate,rather than a flat one.The inversion energy barriers were calculated to be 11.2 kcal/mol and 15.9 kcal/mol for the oxidized and un-oxidized nanoboats,respectively.The electrochemical and photoelectric properties of the synthesized com-pounds were characterized.The band transitions,as well as the aromaticity of the rings in the molecule,were studied DFT calculations.