Self-assembly of 1,4-benzenedimethanethiol self-assembled monolayers on gold.
A study of the self-assembly of 1,4-benzenedimethanethiol (BDMT; HS-CH(2)-(C(6)H(4))-CH(2)-SH) monolayers on gold is presented. Self-assembled monolayers (SAMs) are characterized by reflection-absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE) measurements. The ensemble of measurements consistently shows that well-organized BDMT SAMs, with "standing-up" molecules, can be obtained on high quality gold films with incubation in n-hexane provided that N(2)-degassed solutions are used and all preparation steps are performed at 60 degrees C in the absence of ambient light. SE data indicate that the optical interface properties of the BDMT-Au system are different from those of simple alkanethiol SAMs. A possible mechanism for the formation of the "standing-up" phase from the lying-down phase via a hydrogen exchange reaction involving chemisorbed lying-down and free dithiol molecules is discussed.
Hamoudi
Hicham
H
Université-Paris Sud, Orsay, France.
Prato
Mirko
M
Dablemont
Céline
C
Cavalleri
Ornella
O
Canepa
Maurizio
M
Esaulov
Vladimir A
VA
D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties
D001555:Benzene Derivatives; D008567:Membranes, Artificial; D013438:Sulfhydryl Compounds; D006046:Gold; C512626:1,4-benzenedimethanethiol