New Semifluorinated Dithiols Self-Assembled Monolayers on a Copper Platform

Abstract

New alpha,omega-semifluorinated dithiols HS-(CH2)11-(CF2)n-(CH2)11-SH, called DTn, and corresponding dithioacetate molecules CH3COS-(CH2)11-(CF2)n-(CH2)11-SCOCH3, called DTAn ( n = 4, 6, 8), were synthesized and used to create self-assembled monolayers (SAMs) on both untreated copper surfaces and electrochemically reduced ones. The aim of this study is to assess the organization of the resulting SAMs, particularly the effect of the presence of two perhydrogenated segments surrounding the perfluorinated one, and the ability of these difunctional molecules to bind copper substrates by only one end per molecule. In each case, the organization of the SAM is rather poor and only DTA8 molecules seem to adopt an upright position on reduced copper. In addition, the layers have been investigated by cyclic voltammetry (CV) to assess their coverage. DT4 SAMs reveal a covering ratio higher than 99%.

Semifluorinated thiols in Langmuir monolayers

“…The majority of the fluorinated compounds applied for SAMs preparation are thiols (RASH) [21][22][23], less frequently dialkyldisulfides (R 1 ASASAR 2 ) [24,25] or selenols (RASeH) [26]. The sulfur (selenium) atoms of the functional groups bind strongly to gold; therefore the appropriately prepared gold substrates (most often Au evaporated on the 111 face of the freshly cleaved muscovite mica) are usually applied; however, examples of fluorinated SAMs organized on silver [26], nickel [27] or copper [28] can also be found in literature. Generally, partially fluorinated thiols have excellent prospects.…”

Electrochemical and spectroscopic study of C12H25X molecules adsorption on copper sheets, X (–SH, –S–S–, –SeH and –Se–Se–)

“…Indeed, when SAMs are dense and highly organized, they form a real protective film on the surface making it resistant to ambient oxidation. Surface modification of copper with organothiols self-assembled monolayers has been widely studied and performed during the last decade [1][2][3][4][5][7][8][9][10][14][15][16][17][18]23,25,26,32,33,[44][45][46][47][48][49].…”

Polymer brushes and self-assembled monolayers: Versatile platforms to control cell adhesion to biomaterials (Review)

“…SAMs are formed by adsorption of a variety of functional organic molecules onto suitable solid substrates. Alkanethiols assemble on gold, [67][68][69][70] silver, 71,72 copper, 73 palladium, 74 and platinum 75,76 to provide densely packed molecular monolayers, Fig. 2͑A͒.…”