Cation recognition by cationic receptors is typically challenging due to coulombic repulsion.In this study,we designed a hexacationic receptor,namely,3NDI^(6+).This tricycle naturally adopts a sandwichlike conformatio...Cation recognition by cationic receptors is typically challenging due to coulombic repulsion.In this study,we designed a hexacationic receptor,namely,3NDI^(6+).This tricycle naturally adopts a sandwichlike conformation as its hexafluorophosphate salt([3NDI^(6+)@2PF6^(−)]·4PF6^(−))but then recognizes two chloride anions upon treatment with a chloride anion source.The recognition of the first chloride anion(as an allosteric modulator)facilitates conformational regulation fromthe sandwich-like conformation with a collapsed cavity to a preorganized capsule-like conformation.After conformational switching,the second chloride anion is further recognized to form the inclusion complex[3NDI^(6+)⊃2Cl^(−)]^(4+).The chloridecontaining hexacationic capsule([3NDI^(6+)⊃2Cl^(−)]^(^(4+)))was found to recognize various cations(e.g.,K+from KCl),as supported by the crystal structure of the potassium complex,which revealed a single anionic[KCl_(2)]–entity within the capsule.Prior to conversion to the chloride anion-bound capsule-like form,no evidence of cation recognition is seen by[3NDI^(6+)@2PF_(6)^(−)]·4PF6^(−).The ability to accommodate a cation within the cationic framework of 3NDI^(^(6+))(as[3NDI^(^(6+))⊃2Cl^(−)]·4Cl^(−))is ascribed to specific anion(as Cl^(−))recognition and formation of a capsule-like species,rather than simple charge balance effects.This study presents a new strategy for cation recognition by a cationic capsule that underscores the promise of allosteric control over small-molecule receptor systems.展开更多
Polder is a unique form of reclaimed farmland steeped in human history of long-term adaptation to nature.It embodies traditional agricultural technologies,water conservancy technologies and the culture of the agricult...Polder is a unique form of reclaimed farmland steeped in human history of long-term adaptation to nature.It embodies traditional agricultural technologies,water conservancy technologies and the culture of the agricultural society,providing great value in terms of agricultural heritage.The polder system in Gaochun,Nanjing was born out of the exploitation and use of the lakeside intertidal zone and is a typical example of Jianghuai polders in the Yangtze River delta region.However,because of neglect of its heritage value,the Gaochun polder system is facing the impact of farmland modernisation,and it is urgent to affirm its value and implement dynamic protection.This research explores the historical development and spatial features of the Gaochun polder system,and evaluates its heritage value within the framework of GIAHS(Globally Important Agricultural Heritage Systems)from aspects of(1)food and livelihood security;(2)agro-biodiversity;(3)local and traditional knowledge systems;4)cultures,value systems and social organisations;and 5)landscapes features.Based on our recognition of the agricultural heritage value of the Gaochun polder system,we put forward suggestions for its dynamic conservation and adaptive management while maintaining its productive functions.展开更多
基金the National Key Research and Development Program of China(grant no.2021YFA0910100)the National Natural Science Foundation of China(grant nos.22035006,22320102001,and 22350007)+3 种基金the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(grant no.SN-ZJU-SIAS-006)the“pioneer”and“Leading Goose”R&D Program of Zhejiang(grant no.2025C04010)the Leading Innovation Team grant from the Department of Science and Technology of Zhejiang Province(grant no.2022R01005)for financial support.F.Hthanks the Chemistry Instrumentation Center of Zhejiang University for technical support.We are grateful for the access to the research facilities in Chemistry Department of the University of Hong Kong(HKU).Thework in Austinwas supported by the Robert A.Welch Foundation(F-0018 to J.L.S.).We thank HKU for their continued support of this research.
文摘Cation recognition by cationic receptors is typically challenging due to coulombic repulsion.In this study,we designed a hexacationic receptor,namely,3NDI^(6+).This tricycle naturally adopts a sandwichlike conformation as its hexafluorophosphate salt([3NDI^(6+)@2PF6^(−)]·4PF6^(−))but then recognizes two chloride anions upon treatment with a chloride anion source.The recognition of the first chloride anion(as an allosteric modulator)facilitates conformational regulation fromthe sandwich-like conformation with a collapsed cavity to a preorganized capsule-like conformation.After conformational switching,the second chloride anion is further recognized to form the inclusion complex[3NDI^(6+)⊃2Cl^(−)]^(4+).The chloridecontaining hexacationic capsule([3NDI^(6+)⊃2Cl^(−)]^(^(4+)))was found to recognize various cations(e.g.,K+from KCl),as supported by the crystal structure of the potassium complex,which revealed a single anionic[KCl_(2)]–entity within the capsule.Prior to conversion to the chloride anion-bound capsule-like form,no evidence of cation recognition is seen by[3NDI^(6+)@2PF_(6)^(−)]·4PF6^(−).The ability to accommodate a cation within the cationic framework of 3NDI^(^(6+))(as[3NDI^(^(6+))⊃2Cl^(−)]·4Cl^(−))is ascribed to specific anion(as Cl^(−))recognition and formation of a capsule-like species,rather than simple charge balance effects.This study presents a new strategy for cation recognition by a cationic capsule that underscores the promise of allosteric control over small-molecule receptor systems.
文摘Polder is a unique form of reclaimed farmland steeped in human history of long-term adaptation to nature.It embodies traditional agricultural technologies,water conservancy technologies and the culture of the agricultural society,providing great value in terms of agricultural heritage.The polder system in Gaochun,Nanjing was born out of the exploitation and use of the lakeside intertidal zone and is a typical example of Jianghuai polders in the Yangtze River delta region.However,because of neglect of its heritage value,the Gaochun polder system is facing the impact of farmland modernisation,and it is urgent to affirm its value and implement dynamic protection.This research explores the historical development and spatial features of the Gaochun polder system,and evaluates its heritage value within the framework of GIAHS(Globally Important Agricultural Heritage Systems)from aspects of(1)food and livelihood security;(2)agro-biodiversity;(3)local and traditional knowledge systems;4)cultures,value systems and social organisations;and 5)landscapes features.Based on our recognition of the agricultural heritage value of the Gaochun polder system,we put forward suggestions for its dynamic conservation and adaptive management while maintaining its productive functions.
