AVS 53rd International Symposium
    Surface Science Thursday Sessions
       Session SS2+EM-ThM

Paper SS2+EM-ThM6
Kinetics and Mechanism of Displacement in 1-Adamantanethiolate Self-Assembled Monolayers

Thursday, November 16, 2006, 9:40 am, Room 2004

Session: Self-Assembled Monolayers
Presenter: H.M. Saavedra, The Pennsylvania State University
Authors: H.M. Saavedra, The Pennsylvania State University
C.M. Barbu, The Pennsylvania State University
T.J. Mullen, The Pennsylvania State University
V.H. Crespi, The Pennsylvania State University
P.S. Weiss, The Pennsylvania State University
Correspondent: Click to Email
We have investigated the kinetics of solution-phase displacement of 1-adamantanethiolate self-assembled monolayers on Au{111} by n-dodecanethiol molecules using Fourier transform infrared-external reflectance spectroscopy (FTIR-ERS) and scanning tunneling microscopy (STM). The displacement reaction can be divided into three regions: a fast insertion and nucleation of small n-dodenathiolate islands around defects in the 1-adamantanethiolate monolayer; an island growth regime in which the rate of growth is dependent on the perimeter of the island; and a final slow ordering of the n-dodecanethiolate domains leading to denser and more crystalline n-dodenathiolate domains. A study of displacement as a function of concentration revealed that the full displacement of 1-adamantanethiolate monolayers has a [n-dodecanethiol] x time@super 2@ dependence. An analytical model has been derived to describe the displacement process, and using this model a rate constant has been determined.