AVS 62nd International Symposium & Exhibition
    Surface Science Thursday Sessions
       Session SS+AS+EM+EN-ThM

Paper SS+AS+EM+EN-ThM10
Periodic Trends in the Hydrogen Elimination Thermal Decomposition Reaction on Si(100)-2×1: Linear and Branched Alkyl Halides, Alcohols, and Amines

Thursday, October 22, 2015, 11:00 am, Room 113

Session: Semiconductor Surfaces and Interfaces - I
Presenter: Andrew Pohlman, University of Nevada
Authors: A.J. Pohlman, University of Nevada
K.L. Romolino, University of Nevada
N.J. Burgener, University of Nevada
S.M. Casey, University of Nevada
Correspondent: Click to Email
The hydrogen elimination thermal decomposition reaction was studied on the Si(100)-2×1 surface using temperature programmed desorption mass spectrometry (TPDMS) and electronic structure methods for a selection of linear and branched alkyl halides, alcohols, and primary amines. Desorption activation energies and pre-exponential factors were determined using several analysis techniques from TPDMS spectra and compared to calculations based on ab initio canonical transition state theory using density functional theory (DFT). Values for activation energies and pre-exponential factors for dissociative desorption are compared within an adsorbate class based on a varying ratio of available alpha:beta:gamma hydrogens for elimination. Kinetic parameters are also compared between classes of adsorbates for general structure-activity periodic trends. TPDMS experiments reveal desorbing masses consistent with hydrogen elimination in all cases; however, the different elimination channels remain convoluted. Rate constants for each desorption channel were calculated using DFT and used to determine branching ratios for each dissociative desorption reaction. Reaction barrier trends are consistent with previous reports; however, numerical values were found to be much lower when considering inter-dimer reaction mechanisms.