Inductive Effects on Intramolecular Hydrogen Bond Strength: An Investigation of the Effect of an Electron-Withdrawing CF Group Adjacent to an Alcohol Hydrogen Bond Donor.

This combined experimental and theoretical study seeks to determine the role that inductive effects have on hydrogen bonds by an investigation into the change in intramolecular hydrogen bond strength in 2-amino-1-trifluoromethylethanol (2ATFME) relative to that in 2-aminoethanol (2AE). Toward this end, the rotational spectra of the normal, C, and N isotopologues have been measured using Fourier transform microwave spectroscopy and fit to the rotational, quadrupole coupling, and centrifugal distortion constants of the Watson A-reduction Hamiltonian. Structural parameters used to characterize the strength of the intramolecular hydrogen bond have been determined from the experimental structures of both 2ATFME and 2AE as well as from MP2/6-311++G(d,p) calculations.

Investigation of carbon buildup in simulations of multi-impact bombardment of Si with 20 keV C60 projectiles.

Beams of single C(+) ions are used for the incorporation of Si in the synthesis of thin films of SiC, which have a wide range of technological applications. We present a theoretical investigation of the use of C60 cluster beams to produce thin films of SiC on a Si substrate, which demonstrates that there are potential advantages to using C60(+) cluster ion beams over C(+) single ion beams. Molecular dynamics simulations of the multi-impact bombardment of Si with 20 keV normal incident C60 projectiles are performed to study the buildup of carbon and the formation of a region of Si-C mixing up to a fluence of 1.

Molecule liftoff from surfaces.

Molecular dynamics simulations have been used to model the kiloelectronvolt particle bombardment of organic layers on metal substrates such as occurs in the analytical techniques of secondary ion mass spectrometry and fast atom bombardment mass spectrometry. Vignettes of insights gained from the simulations along with comparisons to experimental data are presented in this Account. Topics include intact molecular ejection vs fragmentation, prediction of reaction pathways, influence of the substrate, and quantitative predictions of energy and angular distributions.

Molecular dynamics simulations of silicon-fluorine etching.

Molecular dynamics simulations of the reactions between gaseous fluorine atoms and (SiFx)n adsorbates on the Si(100) - (2 x 1) surface are performed using the SW potential and compared to simulations with the WWC reparameterization of the SW potential. Theoretical and experimental work has demonstrated that the reactive fluorosilyl layer during silicon-fluorine etching is composed of tower-like adspecies of SiF, SiF2 and SiF3 groups. The objective of the simulations is to determine how the chemical composition, mechanism of formation, and energy distribution of the etched gas-phase products depend on the identity of the reacting adsorbate, the incident kinetic energy, and the parameterization of the potential energy function.