de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Ordered self-assembled monolayers of 4,4 '-biphenyldithiol on polycrystalline silver: Suppression of multilayer formation by addition of tri-n-butylphosphine

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons48442

Mittler,  Silvia
MPI for Polymer Research, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Weckenmann, U., Mittler, S., Naumann, K., & Fischer, R. A. (2002). Ordered self-assembled monolayers of 4,4 '-biphenyldithiol on polycrystalline silver: Suppression of multilayer formation by addition of tri-n-butylphosphine. Langmuir, 18(14), 5479-5486.


Cite as: http://hdl.handle.net/11858/00-001M-0000-000F-659B-4
Abstract
Self-assembled monolayers (SAMs) of 4-biphenylthiol (BT) and 4,4'-biphenyldithiol (BDT) formed on polycrystalline silver substrates were characterized by surface plasmon resonance spectroscopy (SPR), reflection absorption infrared spectroscopy (RAIRS), and X-ray photoelectron spectroscopy (XPS). The RAMS measurements reveal that the molecules in a BT-SAM are oriented perpendicular to the surface whereas the adsorption of BDT results in the formation of multilayers due to the oxidative coupling of the terminal thiol groups forming disulfide-bridged species. The process of multilayer formation was monitored by SPR and RAIRS indicating that BDT initially forms a monolayer which exhibits a structure similar to the one found for BT and that disorder is introduced by the rapid oxidation of the exposed thiol groups resulting in the formation of a multilayer. The addition of tri-n-butylphosphine to the self- assembly solution of 4,4'-biphenyldithiol prevents the formation of multilayers and allows the generation of well- ordered monolayers of the dithiol in which the molecules adopt a standing-up orientation as observed for 4-biphenylthiol. The existence of free thiol groups at the surface of the dithiol SAM was proven by quantitative XPS measurements.