Spectroelectrochemical studies of self assembled monolayers of biphenyl ethynyl thiols on gold electrodes

Jbarah, Abdel Aziz; Döring, Katrin; Lang, Heinrich; Holze, Rudolf

doi:10.1016/j.vibspec.2008.06.004

Cited by 7 publications

(7 citation statements)

References 64 publications

(37 reference statements)

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“…Additionally, the absence of the band associated to the S-H bond (stretching mode around 2565 cm -1 ) confirms its chemisorption on the copper surface (39). The appearance of the strong band between 1082 and 1085 cm -1 caused by the in-plane δ CH mode suggests a less tilted orientation of aromatic thiols (30,37,38). The spectra also show the symmetric (around 2853 cm -1 ) and asymmetric (around 2920 cm -1 ) methylene (-CH 2 ) stretching vibrations and the vibration of the terminal methyl (-CH 3 ) group (around 2966 cm -1 ) (40,41).…”

Section: Polarization Modulation Infrared Reflection Absorption Spectmentioning

confidence: 91%

“…The exposure of FBT and MBT SAMs to DT could result in adsorption of DT at irregularities (defects/pinholes) present within the thioaromatic SAM (7,17,43,44) and/or in a very slow (measured in days) displacement of the aromatic thiols by DT (17,18). The exchange involves proton transfer at the Cu surface followed by desorption according to the bimolecular mechanism proposed by Scheme 1 (18,38). At the beginning of exchange, filling of pinholes or defects occurs, while at later stages the displacement is more likely to occur (17).…”

Section: Polarization Modulation Infrared Reflection Absorption Spectmentioning

confidence: 99%

“…Results obtained by all methods used in this research demonstrate that aromatic thiols do not form ordered and compact films on a copper surface. Thioaromatic SAMs have structural imperfections like defects, pinholes and channels, which influence on the charge transfer reactions at the uncovered substrate⏐electrolyte interface, and lead to ion permeability (7,8,17,18,37,38). It is known that the adsorption of the thioaromatic molecules results in pronounced changes in surface morphology, including an increase in surface roughness and appearance of small monoatomic islands (39).…”

Section: Processes Taking Place During the Electrochemical Modificati...mentioning

confidence: 99%

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Structural and Protecting Properties of Functional Organic Coatings on Copper

Petrović¹,

Metikoš‐Huković²,

Omanovic³

et al. 2010

ECS Trans.

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The paper presents a new approach to the enhancement of structural and barrier properties of thioaromatic self-assembled films on polycrystalline copper. Self-assembled thioaromatic films were modified by potentiodynamic cycling in ethanolic solutions containing milimolar quantities of 1-dodecanethiol. Results obtained using goniometry and polarization modulation infrared reflection absorption spectroscopy demonstrated an improvement in films' structural properties, including higher surface packing density, order and hydrophobicity of electrochemically modified over unmodified thioaromatic films, due to the repair of film defects/pores and exchange. Impedance spectroscopy results showed that the electrochemically modified thioaromatic films offer high corrosion protection in aqueous saline solution, in comparison to spontaneously formed thioaromatic films.

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Section: Polarization Modulation Infrared Reflection Absorption Spectmentioning

confidence: 91%

Section: Polarization Modulation Infrared Reflection Absorption Spectmentioning

confidence: 99%

Section: Processes Taking Place During the Electrochemical Modificati...mentioning

confidence: 99%

See 1 more Smart Citation

Structural and Protecting Properties of Functional Organic Coatings on Copper

Petrović¹,

Metikoš‐Huković²,

Omanovic³

et al. 2010

ECS Trans.

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“…43 The peaks below 1450 cm −1 correspond to C−C deformation (∼1230−950 cm −1 ), C−H stretching (1217 cm −1 ), and C−H bending in pyrene rings (819 cm −1 ). 44,45 In the case of lipoic acid, there is a marked shift in the acid carbonyl frequency from that characteristic of the strongly hydrogen bonded dimer in KBr (1693 cm −1 ) to a value of 1715 cm −1 in the SAM layer, which shows that in the SAM there is a reduction in hydrogen bonding. The ester 2 in KBr shows carbonyl peaks at 1686 (ketone) and 1739 cm −1 (ester).…”

Section: ■ Experimental Sectionmentioning

confidence: 98%

Soft Ultraviolet (UV) Photopatterning and Metallization of Self-Assembled Monolayers (SAMs) Formed from the Lipoic Acid Ester of α-Hydroxy-1-acetylpyrene: The Generality of Acid-Catalyzed Removal of Thiol-on-Gold SAMs using Soft UV Light

Pukenas

Prompinit

Nishitha

et al. 2017

ACS Appl. Mater. Interfaces

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) #& %#" Under a layer of 0.1M HCl in isopropanol, soft UV (365 nm) photolysis of the thiol?on? gold self?assembled monolayer (SAM) derived from the lipoic acid ester of α?hydroxy?1?acetylpyrene results in the expected removal of the acetylpyrene protecting group. By photolyzing through a mask this can be used to produce a patterned surface and, at a controlled electrochemical potential, it is then possible to selectively and reversibly electrodeposit copper on the photolyzed regions. Rather surprisingly, under these photolysis conditions, there is not only the expected photodeprotection of the ester but also partial removal of the lipoic acid layer which has been formed. In further studies, it is shown that this type of acid catalyzed photo?removal of SAM layers by soft UV is a rather general phenomenon and results in the partial removal of the thiol?on?gold SAM layers derived from other ω? thiolated carboxylic acids. However, this phenomenon is chain?length dependent. Under conditions in which there is a ~60% reduction in the thickness of the SAM derived from dithiobutyric acid, the SAM derived from mercaptoundecanoic acid is almost unaffected. The process by which the shorter chain SAM layers are partially removed is not fully understood since these compounds do not absorb significantly in the 365nm region of the spectrum! Significantly, this study shows that acid catalysis photolysis of thiol?on?gold SAMs needs to be used with caution.

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“…Reduc tion of adsorbate oxidation products is not impossible, but taking the shape of the reduction peak this appears to be highly unlikely. This procedure has been applied previously (for an example see [63], this concept has been tested before elsewhere [64][65][66]). The reduction charge in the first scan with the adsorbate covered electrode is 81% of the charge found with the blank electrolyte solution.…”

Section: Mpy Adsorbed From Watermentioning

confidence: 99%