title: Investigation of the deposition and thermal behavior of striped phases of unsymmetric disulfide self-assembled monolayers on Au(111): the case of 11-hydroxyundecyl decyl disulfide.
abstract: Self-assembled monolayers (SAMs) of unsymmetric disulfides on Au(111) are used to form mixed SAMs that can be utilized in many applications. Here, we have studied 11-hydroxyundecyl decyl disulfide (CH3-(CH2)9-S-S-(CH2)11-OH, HDD) SAMs produced by supersonic molecular beam deposition and characterized by He diffraction. The film growth was monitored at different temperatures up to a coverage which corresponds to a full lying down phase and the diffraction analysis shows that below 250 K the phase is different from the phase measured above 300 K. During the annealing of the film, two phase transitions were observed, at 250 K and 350 K. The overall data suggest that the former is related to an irreversible phase separation of HDD above 250 K to decanethiolate (-S-(CH2)9-CH3, DTT) and hydroxyundecylthiolate (-S-(CH2)11-OH, MUDT), while the latter to a reversible melting of the film. Above 450 K, the specular intensity shows an increase related to film desorption and different chemisorbed states were observed with energies in the same range as observed for decanethiol (H-S-(CH2)9-CH3, DT) and mercaptoundecanol (H-S-(CH2)11-OH, MUD) SAMs.
authors.affiliation: Department of Materials and Metallurgical Engineering, Ahi Evran University, Kırşehir 40000, Turkey.
authors.forename: Erol
authors.initials: E
authors.lastname: Albayrak
authors.affiliation: Department of Chemistry, Kahramanmaraş Sütçü İmam University, Kahramanmaraş 46030, Turkey.
authors.forename: Semistan
authors.initials: S
authors.lastname: Karabuga
authors.affiliation: CNR-IMEM and Department of Physics, University of Genoa, via Dodecaneso 33, Genoa 16146, Italy.
authors.forename: Gianangelo
authors.initials: G
authors.lastname: Bracco
authors.affiliation: Department of Chemistry, Middle East Technical University, Ankara 06800, Turkey.
authors.forename: M Fatih
authors.initials: MF
authors.lastname: Danışman
mesh_terms: D004220:Disulfides / Q000138:chemical synthesis / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D044367:Phase Transition; D013696:Temperature
chemical_list: C000604790:11-hydroxyundecyl decyl disulfide; D004220:Disulfides; D006046:Gold