Open AccessSelf-assembly of a metal-ion-bound monolayer of trigonal connectors on mercury: An electrochemical Langmuir trough
Author(s) -
Natalia Varaksa,
Lubomı́r Pospı́šil,
Thomas F. Magnera,
Josef Michl
Publication year - 2002
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.082098299
Subject(s) - chemistry , adsorption , acetonitrile , aqueous solution , monolayer , mercury (programming language) , electrochemistry , langmuir , physisorption , crystallography , metal , inorganic chemistry , analytical chemistry (journal) , electrode , organic chemistry , biochemistry , computer science , programming language
The adsorption of the trigonal connector, 1,3,5-tris[10-(3-ethylthiopropyl)dimethylsilyl-1,10-dicarba-closo-decaboran-1-yl]benzene (1), from acetonitrile/0.1 M LiClO(4) on the surface of mercury at potentials ranging from +0.3 to -1.4 V (vs. aqueous Ag/AgCl/1 M LiCl) was examined by voltammetry, Langmuir isotherms at controlled potentials, and impedance measurements. No adsorption is observed at potentials more negative than approximately -0.85 V. Physisorption is seen between approximately -0.85 and 0 V. At positive potentials, adsorbate-assisted anodic dissolution of mercury occurs and an organized surface layer is formed. Although the mercury cations are reduced at -0.10 V, the surface layer remains metastable to potentials as negative as -0.85 V. Its surface areas per molecule and per redox center are compatible with a regular structure with the connectors 1 woven into a hexagonal network by RR'S-->Hg(2)(2+)<--SRR' or RR'S-->Hg(2+)<--SRR' bridges. The structure is simulated closely by geometry optimization in the semiempirical AM1 approximation.