Macrocyclic Dinuclear Palladium Complex as a Novel Doubly Threaded 3Rotaxane Scaffold and Its Application as a Rotaxane Cross-Linker

摘要

A dinuclear Pd(II)complex possessing a cyclic ligand was developed as a novel doubly threaded 3rotaxane scaffold and applied as a rotaxane cross-linker reagent. The dinuclear complex(PdMC)(2)was prepared by one-step macrocyclization followed by the double palladation reaction.H-1 NMR analysis and UV/Vis measurements revealed the formation of a doubly threaded pseudo3rotaxane by the complexation of(PdMC)(2)with 2 equivalents of 2,6-disubstituted pyridine3through double metal coordination. The treatment of(PdMC)(2)with 2 equivalents of 4-vinylpyridine (VP) afforded a doubly threaded 3rotaxane cross-linker(PdMC-VP)(2). Radical co-polymerization of VP andt-butylstyrene in the presence of(PdMC-VP)(2)afforded a stable rotaxane cross-linked polymer (RCP). An elastic RCP was also prepared by usingn-butyl acrylate as a monomer. The obtained RCPs exhibited higher swelling ability and higher mechanical toughness compared with the corresponding covalent cross-linked polymers.