On the influence of the aliphatic linker on fabrication of highly ordered and orientated self-assembled monolayers of aromatic selenols on AU(111)

Handle URI:
http://hdl.handle.net/10754/563435
Title:
On the influence of the aliphatic linker on fabrication of highly ordered and orientated self-assembled monolayers of aromatic selenols on AU(111)
Authors:
Azzam, Waleed; Al-Rawashdeh, Nathir A F; Al-Refaie, Najd; Shekhah, Osama ( 0000-0003-1861-9226 ) ; Bashir, Asif
Abstract:
Self-assembled monolayers (SAMs) formed by adsorption of 1,2-dibenzyldiselenide (DPMSe) and 1,2-diphenyldiselenide (DBSe) on Au(111) substrates at room temperature have been characterized using scanning tunnelling microscopy, X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and low-energy electron diffraction. Upon adsorption, the Se-Se bonds in DPMSe and DBSe were cleaved on the gold surface to form phenylmethaneselenolate (PMSe) and benzeneselenolate (BSe) species, respectively. Although both PMSe and BSe molecular entities only differ in their structure (an additional methyl group in PMSe), the resulting monolayer films revealed noteworthy dissimilarities regarding their adlayer SAM structure and surface morphology. The molecular adlayer structure and orientation of PMSe and BSe species were found to vary significantly with the immersion time (IT). The resulting PMSe films were poorly organized, and the structure was described by a (4√3 × 2) rectangular unit cell for the SAMs prepared with 24 h of IT. Moreover, the PMSe-SAMs were found to be unstable upon exposure to air for a long time. Our results showed that exposure to air for 48 h results in the formation of small bright ad-islands, which have a height corresponding to that of a single atomic step on the Au(111). Contrary, BSe-SAMs exhibited densely packed and well-ordered monolayers, and two different structural phases were resolved at short and long ITs. The most densely packed structure was obtained for SAMs prepared with very short ITs (10 min). Upon increasing the IT, the SAMs exhibited structural changes to a lower density of molecular packing structure. The spectroscopic data also confirmed this structural transformation by suggesting an upright orientation for BSe-SAMs prepared after short ITs and strongly inclined adsorption geometry for SAMs prepared after long ITs. © 2014 American Chemical Society.
KAUST Department:
Advanced Membranes and Porous Materials Research Center
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry C
Issue Date:
6-Mar-2014
DOI:
10.1021/jp500069g
Type:
Article
ISSN:
19327447
Sponsors:
The author W.A. would like to thank TTU for granting him sabbatical leave to Umm Al-Qurrah University, Saudi Arabia. Also, W.A. and N.A.F.A-R. gratefully acknowledge the short-term research fellowship supported by the DFG. W.A. and N.A.F.A-R. gratefully acknowledge TTU (Tafila Technical University) and JUST (Jordan University of Science and Technology) for their partial support during the DFG visit.
Appears in Collections:
Articles; Advanced Membranes and Porous Materials Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorAzzam, Waleeden
dc.contributor.authorAl-Rawashdeh, Nathir A Fen
dc.contributor.authorAl-Refaie, Najden
dc.contributor.authorShekhah, Osamaen
dc.contributor.authorBashir, Asifen
dc.date.accessioned2015-08-03T11:51:23Zen
dc.date.available2015-08-03T11:51:23Zen
dc.date.issued2014-03-06en
dc.identifier.issn19327447en
dc.identifier.doi10.1021/jp500069gen
dc.identifier.urihttp://hdl.handle.net/10754/563435en
dc.description.abstractSelf-assembled monolayers (SAMs) formed by adsorption of 1,2-dibenzyldiselenide (DPMSe) and 1,2-diphenyldiselenide (DBSe) on Au(111) substrates at room temperature have been characterized using scanning tunnelling microscopy, X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and low-energy electron diffraction. Upon adsorption, the Se-Se bonds in DPMSe and DBSe were cleaved on the gold surface to form phenylmethaneselenolate (PMSe) and benzeneselenolate (BSe) species, respectively. Although both PMSe and BSe molecular entities only differ in their structure (an additional methyl group in PMSe), the resulting monolayer films revealed noteworthy dissimilarities regarding their adlayer SAM structure and surface morphology. The molecular adlayer structure and orientation of PMSe and BSe species were found to vary significantly with the immersion time (IT). The resulting PMSe films were poorly organized, and the structure was described by a (4√3 × 2) rectangular unit cell for the SAMs prepared with 24 h of IT. Moreover, the PMSe-SAMs were found to be unstable upon exposure to air for a long time. Our results showed that exposure to air for 48 h results in the formation of small bright ad-islands, which have a height corresponding to that of a single atomic step on the Au(111). Contrary, BSe-SAMs exhibited densely packed and well-ordered monolayers, and two different structural phases were resolved at short and long ITs. The most densely packed structure was obtained for SAMs prepared with very short ITs (10 min). Upon increasing the IT, the SAMs exhibited structural changes to a lower density of molecular packing structure. The spectroscopic data also confirmed this structural transformation by suggesting an upright orientation for BSe-SAMs prepared after short ITs and strongly inclined adsorption geometry for SAMs prepared after long ITs. © 2014 American Chemical Society.en
dc.description.sponsorshipThe author W.A. would like to thank TTU for granting him sabbatical leave to Umm Al-Qurrah University, Saudi Arabia. Also, W.A. and N.A.F.A-R. gratefully acknowledge the short-term research fellowship supported by the DFG. W.A. and N.A.F.A-R. gratefully acknowledge TTU (Tafila Technical University) and JUST (Jordan University of Science and Technology) for their partial support during the DFG visit.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleOn the influence of the aliphatic linker on fabrication of highly ordered and orientated self-assembled monolayers of aromatic selenols on AU(111)en
dc.typeArticleen
dc.contributor.departmentAdvanced Membranes and Porous Materials Research Centeren
dc.identifier.journalThe Journal of Physical Chemistry Cen
dc.contributor.institutionDepartment of Chemistry, Tafila Technical University, P.O. Box 179, Tafila-66110, Jordanen
dc.contributor.institutionDepartment of Chemistry, University College in Al-Qunfudah, Umm Al-Qura University, 1109 Makkah Al-Mukarramah, Saudi Arabiaen
dc.contributor.institutionDepartment of Applied Chemical Sciences, Jordan University of Science and Technology, P.O. Box 3030, Irbid-22110, Jordanen
dc.contributor.institutionDepartment of Chemistry, College of Science, United Arab Emirates University, P.O. Box 15551, Al Ain, Abu Dhabi, United Arab Emiratesen
dc.contributor.institutionMax-Planck-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Düsseldorf, Germanyen
kaust.authorShekhah, Osamaen
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