Rapid Formation of a Dense Sulfur Layer on Gold through Use of Triphenylmethane Sulfenyl Chloride as a Precursor

Abstract

The use of triphenylmethane sulfenyl chloride as a new precursor leads to the efficient deposition of sulfur on polycrystalline gold and Au(111) substrates. The modified surfaces are characterized using X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning tunneling microscopy (STM). The XPS data shows the rapid deposition of polymeric sulfur within very short times. Electrochemical stripping cyclic voltammetry (CV) confirms the rapid deposition and shows that high coverage values are achieved. STM imaging shows the formation of a wide range sulfur layer and production of the well-known etch pits. High-resolution STM images confirm the high density of the sulfur layers and show formation of a long-range phase consisting of rhombus structures close to the previously described rectangular structures along with other parallelograms and partial parallelograms. The present results do not show the initial formation of any organic self-assembled monolayer (SAM) indicating that the formation of polymeric sulfur does not result from the decomposition of an initial SAM as previously observed with alkyl and aryl thiolate-based SAMs. The suggested mechanism involves an initial reductive process similar to the one reported for thiocyanates and sulfenyl chlorides. This is followed by the dissociation of the Ph(3)C-S bond, leaving only sulfur on the surface, through a process leading to the recombination of the remaining fragments to yield triphenylmethyl chloride.

Surface Chemistry of Thiomalic Acid Adsorption on Planar Gold and Gold Nanoparticles

“…30,47,48 As well as TMA, those thiols have electronwithdrawing groups or a double bond close to the C−S bond. The tendency of thiols to suffer C−S bond scission can rely on different factors.…”

A scanning tunneling microscopy investigation of the phases formed by the sulfur adsorption on Au(100) from an alkaline solution of 1,4-piperazine(bis)-dithiocarbamate of potassium

“…A large diversity in molecular arrangements at intermediate and high sulfur coverages on Au(111) has been reported using STM. Some of these are the octomer formed by a quasi-square structure with eight atoms [33][34][35] and distortions of this phase, where certain sulfur atoms have slightly changed positions to generate different arrangements on the Au(111) surface [24,25,35,36]. Other interesting structure which forms a zig-zag pattern has been also observed [25].…”

Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

“…On the other hand, it has been considered that rectangles are formed by entities of eight sulfur atoms (a sulfur octomer). [2][3][4][7][8][9][10][11][12] Lustemberg et al 7 perform one of the most extended studies that sustains this approach supported by STM and X-ray photoemission spectroscopy (XPS) as well as electrochemistry experiments and surface enhanced Raman spectroscopy (SERS). This work and those previously reported by Vericat et al 3,4 use an aqueous solution of sodium sulfide and sodium hydroxide at room temperature, verifying the oxidation and deposition of sulfide anions on the Au(111) surface.…”

“…Since the beginning of the 1990s, peculiar scanning tunneling microscopy (STM) images related to the deposition of sulfur atoms on Au(111) surfaces have been the focus of attention of numerous papers about surface science. [1][2][3][4][5][6][7][8][9][10][11][12] Those images show rectangular formations and the atomic resolution allows to distinguish eight atomic centers per rectangular structure. 3,[8][9][10] As precursors for sulfur deposition, the list ranges from sulfide anions in aqueous solutions [2][3][4]7 to gaseous molecules such as sulfur dioxide 5,6 to organosulfur compounds [8][9][10][11][12] which decompose on the Au(111) surface leaving the sulfur atoms free.…”

“…The rectangular patterns have also been observed in STM images when solutions of organosulfur compounds have been put in contact with Au(111) surfaces. The reports include hexamethyldisilathiane, 8 and different substituted arene sulfonyl phthalimides 11 as well as dithiobisphthalimide, 9 triphenylmethane sulfenyl chloride 10 and thiobis-(hexamethyldisilazane). 12 In these cases, XPS experiments are only able to detect the 2p 3/2 sulfur signals and there are no peaks that could indicate the presence of other entities on the surface such as silicon atoms and aromatic or phthalimide moieties.…”