Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot con...Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot condensation of commercially available 2,6-DMA and paraformaldehyde in 1,2-dichlorobenzene(o-DCB)at room temperature.P5 showed a highly symmetrical pentagonal structure with a large and deep electron-rich cavity,which made it form stable 1∶2 host–guest complexes with various aryl-pyridinium,bipyridinium,and stilbazolium salts in solution.Interestingly,P5 could complex two or even three guests with its intrinsic cavity and the pseudocavity formed by the adjacent macrocycles in solid states.Moreover,the strong intermolecular charge-transfer(ICT)interactions between P5 and the guests were observed.Especially,the complexes formed by P5 and the protonated pyridinium or bipyridinium salts showed acid/base-responsive color changes in solution and remarkable crystalline vapochromic properties by two kinds of processes:from ICT to no ICT and from ICT to enhanced ICT interaction or vice versa.We believe that the easily available P5 with the specific structure and intriguing 1∶2 host–guest complexation can find wide application in supramolecular assemblies and functional materials.展开更多
基金The authors thank the National Natural Science Foundation of China(nos.22031010,21772205,21521002,and 91856117)for financial support.
文摘Pagoda[5]arene(P5),which is composed of five 2,6-dimethoxylanthracene(2,6-DMA)subunits bridged by methylene groups at 1,5 positions,was conveniently synthesized in 43%by trifluoroacetic acid(TFA)-catalyzed one-pot condensation of commercially available 2,6-DMA and paraformaldehyde in 1,2-dichlorobenzene(o-DCB)at room temperature.P5 showed a highly symmetrical pentagonal structure with a large and deep electron-rich cavity,which made it form stable 1∶2 host–guest complexes with various aryl-pyridinium,bipyridinium,and stilbazolium salts in solution.Interestingly,P5 could complex two or even three guests with its intrinsic cavity and the pseudocavity formed by the adjacent macrocycles in solid states.Moreover,the strong intermolecular charge-transfer(ICT)interactions between P5 and the guests were observed.Especially,the complexes formed by P5 and the protonated pyridinium or bipyridinium salts showed acid/base-responsive color changes in solution and remarkable crystalline vapochromic properties by two kinds of processes:from ICT to no ICT and from ICT to enhanced ICT interaction or vice versa.We believe that the easily available P5 with the specific structure and intriguing 1∶2 host–guest complexation can find wide application in supramolecular assemblies and functional materials.
