title: Rapid proton-coupled electron-transfer of hydroquinone through phenylenevinylene bridges.
abstract: We describe the synthesis of two oligo(phenylene vinylene)s (OPVs) with a hydroquinone moiety and a thiol anchor group: 4-(2',5'-dihydroxystyryl)benzyl thioacetate and 4-[4'-(2' ',5' '-dihydroxystyryl)styryl]benzyl thioacetate. Monolayers on gold of these molecules were examined by electrochemical techniques to determine the electron transfer kinetics of the hydroquinone functionality (H2Q) through these delocalized tethers ("molecular wires") as a function of pH. Between pH 4 and 9, rate constants were ca. 100-fold faster than for the same H2Q functionality confined to the surface via alkane tethers. Also, in this same pH range rate constants were independent of the length of the OPV bridge. These new electroactive molecules in which the hydroquinone functionality is wired to the gold surface by means of OPV tethers should be useful platforms for constructing bioelectronic devices such as biosensors, biofuel cells, and biophotovoltaic cells with a fast response time.
authors.affiliation: Center for Bio-Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA. scott.trammell@nrl.navy.mil
authors.forename: Scott A
authors.initials: SA
authors.lastname: Trammell
authors.forename: Dwight S
authors.initials: DS
authors.lastname: Seferos
authors.forename: Martin
authors.initials: M
authors.lastname: Moore
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Lowy
authors.forename: Guillermo C
authors.initials: GC
authors.lastname: Bazan
authors.forename: James G
authors.initials: JG
authors.lastname: Kushmerick
authors.forename: Nikolai
authors.initials: N
authors.lastname: Lebedev
mesh_terms: D002627:Chemistry, Physical / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004583:Electrons; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006873:Hydroquinones / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D011145:Polyvinyls / Q000737:chemistry*; D011522:Protons; D013997:Time Factors; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D006873:Hydroquinones; D011145:Polyvinyls; D011522:Protons; D014753:Vinyl Compounds; D006046:Gold; C031927:hydroquinone