摘要
Metal-organic cages can undergo structural transformations due to the dynamic nature of dative bonds,however,the mechanism of transformation processes is often unclear.Herein we report four metal-organic cages featuring Pd_(3)L_(6)-type and Pd_(4)L_(8)-type tubular structures by self-assembly of Pd(Ⅱ)and two types of bidentate metalloligands.The Pd_(3)L_(6)-type MOCs were synthesized in H_(2)O while the Pd_(4)L_(8)-type cages were formed in dimethyl sulfoxide(DMSO),indicating the solvent is critical for the assembly.The structure transformation between Pd_(3)L_(6)and Pd_(4)L_(8)metal-organic cages can be interconverted when switching the DMSO and H_(2)O in a relatively high concentration.The cages partly disassemble into the metalloligands and Pd^(2+)ions due to the competitive coordination of DMSO/H_(2)O at low concentrations,achieving a concentration-controlled transformation process.Moreover,the structure transformation was monitored by ESI-MS,and the species of intermediate were detected,which provided direct clues for deciphering the mechanism of structural transformation.
基金
supported by the National Natural Science Foundation of China(22375075,22171106,22471098,22201101)
the Guangdong Major Project of Basic and Applied Research(2019B030302009)
the Guangdong Natural Science Foundation(2022A1515011937)
Jinan University。
