title: Oxygen attachment on alkanethiolate SAMs induced by low-energy electron irradiation.
abstract: Reactions of (18)O2 with self-assembled monolayer (SAM) films of 1-dodecanethiol, 1-octadecanethiol, 1-butanethiol, and benzyl mercaptan chemisorbed on gold were studied by the electron stimulated desorption (ESD) of anionic fragments over the incident electron energy range 2-20 eV. Dosing the SAMs with (18)O2 at 50 K results in the ESD of (18)O(-) and (18)OH(-). Electron irradiation of samples prior to (18)O2 deposition demonstrates that intensity of subsequent (18)O(-) and (18)OH(-) desorption signals increase with electron fluence and that in the absence of electron preirradiation, no (18)O(-) and (18)OH(-) ESD signals are observed, since oxygen is unable to bind to the SAMs. A minimum incident electron energy of 6-7 eV is required to initiate the binding of (18)O2 to the SAMs. O2 binding is proposed to proceed by the formation of CHx-1(•) radicals via resonant dissociative electron attachment and nonresonant C-H dissociation processes. The weaker signals of (18)O(-) and (18)OH(-) from short-chain SAMs are related to the latter's resistance to electron-induced damage, due to the charge-image dipole quenching and electron delocalization. Comparison between the present results and those for DNA oligonucleotides self-assembled on Au (Mirsaleh-Kohan, N. et al. J. Chem. Phys. 2012, 136, 235104) indicates that the oxygen binding mechanism is common to both systems.
authors.affiliation: Groupe en sciences des radiations, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke (QC) J1H 5N4, Canada. Sylvain.Massey@USherbrooke.ca
authors.forename: Sylvain
authors.initials: S
authors.lastname: Massey
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bass
authors.forename: Marie
authors.initials: M
authors.lastname: Steffenhagen
authors.forename: Léon
authors.initials: L
authors.lastname: Sanche
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D004583:Electrons; D010100:Oxygen / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000473:Alkanes; D013438:Sulfhydryl Compounds; D010100:Oxygen
references.citation: Phys Rev Lett. 2000 Jun 5;84(23):5363-6
references.pmid: 10990944
references.citation: Int J Radiat Biol. 1994 Nov;66(5):491-7
references.pmid: 7983436
references.citation: Nanoscale. 2012 Mar 21;4(6):2093-100
references.pmid: 22344204
references.citation: J Phys Chem B. 2011 Apr 21;115(15):4523-31
references.pmid: 21452797
references.citation: J Colloid Interface Sci. 2009 Dec 1;340(1):126-30
references.pmid: 19740476
references.citation: Chem Rev. 2005 Apr;105(4):1103-69
references.pmid: 15826011
references.citation: J Chem Phys. 2004 Jun 1;120(21):10225-30
references.pmid: 15268046
references.citation: Faraday Discuss. 2010;146:353-65; discussion 367-93, 395-401
references.pmid: 21043432
references.citation: Chem Soc Rev. 2010 Jan;39(1):354-78
references.pmid: 20023857
references.citation: J Chem Phys. 2012 Jun 21;136(23):235104
references.pmid: 22779623
references.citation: J Control Release. 2006 Aug 10;114(1):60-8
references.pmid: 16828916
references.citation: Radiat Res. 1999 Aug;152(2):144-53
references.pmid: 10409323
references.citation: Langmuir. 2010 May 4;26(9):6508-14
references.pmid: 20000594
references.citation: Phys Chem Chem Phys. 2009 Mar 14;11(10):1610-8
references.pmid: 19240939
references.citation: Anal Chem. 2010 Sep 1;82(17):7335-42
references.pmid: 20698498
references.citation: Langmuir. 2012 Jan 10;28(1):367-76
references.pmid: 22084928
references.citation: J Am Chem Soc. 2003 Mar 5;125(9):2597-609
references.pmid: 12603148
references.citation: J Am Chem Soc. 2005 Dec 14;127(49):17315-22
references.pmid: 16332081
references.citation: Acc Chem Res. 2000 Jul;33(7):457-66
references.pmid: 10913234