Selective synthesis and physical properties of a bismacrocycle:Cycloparaphenylene-pillar[5]arene

Macrocyclic materials have attracted much attention due to their particular chemical and physical properties.Herein we report the precise synthesis and characterization of a new bismacrocycle structure base on cycloparaphenylene(CPP)and pillar[5]arene,named cycloparaphenylene-pillar[5]arenes(CPPn[5]).The bismacrocycle was fully characterized by NMR and HR-MS.The photophysical properties of CPPn[5]were investigated by UV–vis,and the maximum absorption peak was located at 331 nm,which was consistent with density functional theory(DFT)calculations.The fluorescence spectrum was further studied and the emission peak was maximized at 458 nm.The computational results indicate the strain energy of CPPn[5]is 27.80 kcal/mol and the HOMO-LUMO gap is 3.39 eV Notably,CPPn[5]showed interesting supramolecular properties.