5-(4-pyridinyl)-1,3,4-oxadiazole-2-thiol on gold: SAM Formation and electroactivity

Journal of the Brazilian Chemical Society

Tercio De F. Paulo²  Maria A. S. Da Silva²  Solange De O. Pinheiro²  Emerson Meyer²  Lucidalva S. Pinheiro¹  José A. Freire¹  Auro A. Tanaka¹  Pedro De Lima Neto¹  Ícaro De S. Moreira²  Izaura C. N. Diógenes² 

[1] ,Universidade Federal do Ceará Centro de Ciências Departamento de Química Orgânica e InorgânicaFortaleza CE ,Brazil

关键词: oxadiazole;    thiol;    SAMs;    STM;    kinetic of adsorption;    Cyt c;   

DOI  :  10.1590/S0103-50532008000400015

来源: SciELO

【 摘 要 】

5-(4-pyridinyl)-1,3,4-oxadiazole-2-thiol (Hpyt) spontaneously adsorbs on gold forming SAMs (self-assembled monolayers) that, based on STM (Scanning Tunneling Microscopy) and electrochemical data, contain pinholes through which [Fe(CN)6]4- and [Ru(NH3)6]3+ probe molecules access the underlying gold electrode. For the former molecule, the dependence of the faradaic current on the electrolyte solution pH value allowed the evaluation of the surface pKa as 4.2. The thermodynamic parameters DHads and DGads for the Hpyt adsorption process could be described by the Langmuir model and were calculated as -20.01 and -39.39 kJ mol-1, respectively. Electrodic redox reaction of cytochrome c metalloprotein was accessed by using the Hpyt SAM with a heterogeneous electron transfer rate constant of 2.29 × 10-3 cm s-1.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License