STM study of 2-mercaptoethanol self-assembled monolayer on Au(111)

Authors
Citation
M. Hyun et Ck. Rhee, STM study of 2-mercaptoethanol self-assembled monolayer on Au(111), B KOR CHEM, 22(2), 2001, pp. 213-218
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry
Journal title
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
ISSN journal
0253-2964 → ACNP
Volume
22
Issue
2
Year of publication
2001
Pages
213 - 218
Database
ISI
SICI code
0253-2964(20010220)22:2<213:SSO2SM>2.0.ZU;2-0
Abstract
Presented are the STM images of self-assembled monolayer of 2-mercaptoethan ol on Au(111). Striped structures of (6X root3), (5X root3), (4X root3) and compact-(5X root3) were observed after annealing at 80 degreesC. Analysis of the ordered structures revealed that the basic fundamental units of the ordered structures were three crystallographically non-equivalent (root 3X root3)R30 degrees assemblies, and that the way of combination of the assemb lies produced the four different structures. The (6X root3) structure (thet a = 0.33) was composed of one (root 3X root3)R30 degrees assembly, while th e (5X root3) (theta = 0.30) and (4X root3) (theta = 0.38) structures were c onsisted of two (root 3X root3) R30 degrees assemblies, separated by 5a and 4a, respectively. Furthermore, the compact-(5X root3) structure (theta = 0 .50) was obtained by overlapping three (root 3X root3)R30 degrees assemblie s. In spite of the diversity in the adsorption structures, all the adsorpti on sites of 2-mercaptoethanol were fundamentally identical. On the other ha nd, the unannealed primitive SAM of 2-mercaptoethanol was characterized by two observations: a short-range order keeping the adsorbed molecules at app roximately root3 a and the small domains of the striped structures supporti ng that the observed surface structures on the annealed surface were the ex tension of the primitive layer of 2-mercaptoethanol. Comparing these observ ations with the already published structures of ethanthiol, it was conclude d that the interaction between the hydroxyl groups of 2-mercaptoethanol mig ht play a significant role in the adsorption step of 2-mercaptoethanol on A u(111) to organize the adsorption structures different from those of ethant hiol.