Three-Dimensional Conjugated Molecules Functionalized By Five/Seven-Membered Ring Defect And Malononitrile Radicals

Three-dimensional(3D)conjugated molecular materials possess diverse molecular skeletons and extended π-electron structures that offer excellent solubility,easy chemical modification and processing,and multifunctional integration of optical,electrical,and magnetic properties.As a result,they have a broad application prospect in the field of organic functional materials.However,the design and synthesis of 3D conjugated functional molecular materials require careful consideration of the introduction of suitable elements or controllable reactions,such as defect-mediated 3D spatial intermolecular coupling reaction formed by radicals.Current research hotspots in the field of 3D conjugated molecular materials include 3D fused aromatic molecules with five/seven-membered ring topological defects and malondiitrile radical-mediated3 D conjugated responsive functional molecules,which have been applied in organic field effect transistors,organic solar cells,organic storage components,and smart sensor devices,among others.The topological backbones and conjugated π-structures are essential for determining the expression of the photoelectromagnetic properties and the source of multifunctional properties of 3D conjugated systems.Therefore,the precise construction of novel 3D fused aromatic molecules and adaptive 3D conjugated molecules is a research focus and a challenging point in this field.In order to construct3 D conjugated functional molecular materials,synthesize novel fused aromatic functional molecules with better photoelectromagnetic properties,we have developed new methods for the synthesis of asymmetric fulvalene and N-doped seven-membered ring molecules.Also we have constructed adaptive 3D porous molecular frameworks and systematically studied the conformational relationships between 3D skeleton structures and properties and the multifunctional properties of 3D porous molecular frameworks.Our research includes the following specific contents:1)We have synthesized asymmetric benzopentafulvalenes by skeleton rearrangement reaction of difluorenylidene cyclobutene,researched the mechanism of rearrangement reaction,and expanded the molecular materials library.We have studied the photoelectric properties and aggregation states through molecular size effect and substituent effect.Stable radical cation and radical anion have been synthesized,and the optical properties,electronic structure,and corresponding magnetic properties have been researched by spectral analysis and theoretical calculations.Finally,we have used the new fulvalene material as the active layer and passivation layer to prepare organic field effect transistors(OFETs)with stable balanced bipolar transport properties,as well as perovskite solar cells with good stability.2)We have synthesized N-doped seven-membered ring compounds with a distorted backbone structure and systematically studied the optical and electrochemical properties of these new compounds.Radical cations have been prepared,and the electronic structure,aromaticity,and magnetic properties have been studied systematically.3)Novel three-dimensional cyclic trimers and polymeric framework materials have been successfully synthesized in our research.To understand their structural properties,we employed single crystal X-ray diffraction to study the skeletal and porous structure of cyclic trimer.Our experimental and theoretical calculations provided strong evidence for the efficient construction of cyclic trimers in an adaptive porous framework.4)We conducted a comprehensive characterization of the optical,electrical,and magnetic properties of the cyclic trimers and polymers synthesized in our study.In addition,we investigated the pore structure and adsorption properties of the porous framework materials through gas adsorption experiments.Furthermore,we systematically characterized the bistable magnetic properties and reversible response properties of the oligomers,providing valuable insights into their potential applications in diverse fields.