Effect of solution pH on the structure of a 4-mercaptopyridine monolayer self-assembled on Au(111)

Wan, Li‐Jun; Noda, Hiroyuki; Hara, Yosuke; Osawa, Masatoshi

doi:10.1016/s0022-0728(00)00198-4

Cited by 40 publications

(51 citation statements)

References 19 publications

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“…[1][2][3][4][5] Recently, the as-prepared organic monolayers were proved to be ideal models to study phase transition in lowdimensional systems, which provide a new possibility for the fabrication of nanoscale electronic devices. 6 The emergence of scanning tunneling microscopy (STM), which can directly address nanoscale structures at various interfaces, [7][8][9][10][11][12] has brought fascinating advances. A large number of reports have described phase transitions in organic monolayers on metal surfaces.…”

Section: Introductionmentioning

confidence: 99%

Potential-Induced Phase Transition of Trimesic Acid Adlayer on Au(111)

et al. 2004

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Potential-induced phase transition of trimesic acid (TMA, C 6 H 3 (COOH) 3 ) on a Au(111) electrode was investigated by in situ scanning tunneling microscopy (STM) and cyclic voltammetry. A pair of peaks, ascribed to structural transformation was observed in the cyclic voltammograms (CVs) of Au(111) in 0.1 M HClO 4 + 0.1 mM TMA. The magnitude of the peaks decreased with increasing solution pH. On the basis of highresolution STM images in 0.1 M HClO 4 , it is proposed that TMA molecules assume a flat-lying and a vertical orientation at 0.25 and 0.85 V, respectively. The coexistence of the two orientations was observed at 0.65 V. The discovered adlayer phases could be represented by (4×4), (5×2 3), and (2 3× 4 3) or (7×2 3) structures. Intriguingly, it is found that TMA molecules bind on Au substrate with one and two deprotonated carboxyl groups with potential shifting, even though the molecules take the same vertical orientation. On the basis of the STM observation, structural models for various adlayers are proposed. Comparing the STM results with those of cyclic voltammetry, we conclude that the potential-induced phase transitions in 0.1 M HClO 4 solution result from the interfacial deprotonation/protonation of the TMA molecules.

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Section: Introductionmentioning

confidence: 99%

Potential-Induced Phase Transition of Trimesic Acid Adlayer on Au(111)

et al. 2004

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“…More recently, electrochemical studies with alkanethiol (H-(CH 2 ) n SH) SAMs were performed by several groups [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Alkanethiols usually form a commensurate ( ffiffi ffi 3 p Â ffiffi ffi 3 p )R30°structure on Au(1 1 1), whereas on Ag(1 1 1) a distorted hexagonal structure was commonly observed for n > 1.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical and structure studies of ethanethiol self-assembled monolayers on Ag single crystal electrodes

Schweizer¹,

Kolb²

2004

Journal of Electroanalytical Chemistry

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“…Such a disulfide-like adsorbate is stable only in strongly acidic solutions. 21 Moreover, a combination of spectral data and molecular modeling 17 indicated that there might be microcavities formed between adjacent protonated pyridinium moieties on the SAM surface that result in a threedimensional structure complementary in both shape and chemical functionality to that of the chromate ion. During the initial cathodic sweep, the hydrogen bonding is broken as Cr͑VI͒ is reduced to lower oxidation states.…”

Section: ͑8͒mentioning

confidence: 99%

Selective detection of Cr(VI) using a microcantilever electrode coated with a self-assembled monolayer

Tian

Boiadjiev

Pinnaduwage

et al. 2005

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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We have demonstrated detection of Cr(VI) ions using functionalized microcantilevers under electrochemical control. Au-coated microcantilever working electrodes are modified with self-assembled monolayers of 4-mercaptopyridine (4-mPy) in sulfuric acid solution. Differential surface stress changes at the modified microcantilever have been measured as a function of applied potential while simultaneously measuring the current-potential response by cyclic voltammetry. The selective adsorption of Cr(VI) on 4-mPy monolayer-coated microcantilever electrode is attributed to hydrogen bonding. The stressogram (first derivative of surface stress of microcantilever with respect to potential versus electrode potential) suggests that a small amount of an intermediate oxidation state of chromium is retained at the 4-mPy monolayer, and this intermediate reduction product of Cr(VI) can be reversibly oxidized on the surface. Our results demonstrate that changes of differential surface stress due to the adsorption-controlled electrochemical reaction can be observed at high sensitivity. This potential controlled microcantilever technique offers insights into the behavior of the solid-liquid interface during electrochemical reactions at modified electrodes.

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Effect of solution pH on the structure of a 4-mercaptopyridine monolayer self-assembled on Au(111)

Cited by 40 publications

References 19 publications

Potential-Induced Phase Transition of Trimesic Acid Adlayer on Au(111)

Potential-Induced Phase Transition of Trimesic Acid Adlayer on Au(111)

Electrochemical and structure studies of ethanethiol self-assembled monolayers on Ag single crystal electrodes

Selective detection of Cr(VI) using a microcantilever electrode coated with a self-assembled monolayer

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