title: Construction of a pH-driven supramolecular nanovalve.
abstract: [Structure: see text] The versatility of supramolecular chemistry has been exploited in constructing nanovalves based on mesoporous silica MCM-41 and the mutual recognition between secondary dialkylammonium ions and dibenzo[24]crown-8 (DB24C8). Naphthalene-containing dialkylammonium threads were tethered to the MCM-41, followed by loading with coumarin 460 and capping with DB24C8. Controlled release of coumarin 460 from the pores of MCM-41 was demonstrated using different bases. The rate of release of coumarin 460 from the nanovalves depends on the size of the base.
authors.affiliation: California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095, USA.
authors.forename: Thoi D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Ken C-F
authors.initials: KC
authors.lastname: Leung
authors.forename: Monty
authors.initials: M
authors.lastname: Liong
authors.forename: Cari D
authors.initials: CD
authors.lastname: Pentecost
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink
mesh_terms: D003374:Coumarins / Q000737:chemistry; D043844:Crown Ethers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003374:Coumarins; D043844:Crown Ethers; C509968:MCM-41; D000644:Quaternary Ammonium Compounds; D012822:Silicon Dioxide