Synthesis Of Novel Difluoroboron ?-Diketone Complexes Macrocycles Aromatic Hydrocarbons And Construction Of Metal Poly[2]pseudorotaxane

Host-guest chemistry is the core content of the field of supramolecular chemistry,and molecular self-assembly is the ultimate goal of supramolecular chemistry.Now supramolecular chemistry has made rapid progress on the basis of these two aspects.The design and development of large-sized cavities and specific functional macrocycles are challenging tasks in supramolecular chemistry.Fluorescent groups are embedded on the basis of biphen[n]arenes to synthesize a new type of supramolecular macrocyclic host with fluorescent function,which has potential applications in the field of supramolecular sensing.Difluoroboron ?-diketone unit is a kind of fluorophore with rich photophysical properties.First,a bis?2,4-dimethoxyphenyl?substituted difluoroboron ?-diketone complex?BF₂bdk-BP?was synthesized.The mechanofluochromic behavior of solid powder was reversible.Then,compound BF₂bdk-BP as monomer was used and reacted with paraformaldehyde under Lewis acid catalysis to synthesize difluoroboron ?-diketone-based dimer macrocycle compound?BF₂bdk-BP2?and trimer macrocycle compound?BF₂bdk-BP3?in one step.The structure of the novel fluorescent macrocycle compound was characterized by 1H NMR,MS,and X-ray single crystal diffraction.And through the dimer macrocycle compound and monomer compound under high pressure mechanofluochromic experiments,the superiority of macrocyclic compounds with sensitive stimulus response was demonstrated.Finally,a dynamic metal polypseudorotaxane based on pillar[5]arene [2]pseudorotaxane driven by the coordination of metal palladium???ion was constructed.The formation of [2]pseudorotaxane and its self-assembly supramolecular polymers confirmed by ¹H NMR,2D NOESY,DOSY,dynamic light scattering,viscosity,and SEM characterization methods.It was further found that the metal polypseudorotaxane formed a gel at a high concentration and could be temperature-responsive.