Synthesis of o-?-mercapto [poly(ethyleneoxy)]-o'-alkylhydroquinol derivatives and formation of novel pseudorotaxanes

A series of monofunctionalized hydroquinol oligoether chains terminated by thiols were designed and synthesized from unsymmetric starting materials in good yields by multi-procedure reactions at mild temperatures. In a thermodynamically controlled self-assembly process, several pseudorotaxanes based on the π-electron-rich hydroquinol oligoether thiols and π-electron deficient cyclobis(paraquat-p-phenylene) (CPQT) were formed. Furthermore, a gold cation was added to the self-assembly systems and 1H NMR studies on the thiol/Au systems revealed that Au3+ is an efficient terminal stopper of pseudorotaxanes or rotaxanes; the pseudorotaxane can be unthreaded or rethreaded at different temperatures. These could be a basis for the future development of mechanoelectrical and photoelectrical communication systems, and devices capable of storing and processing information.