Experimental and simulation study of neon collision dynamics with a 1-decanethiol monolayer

Abstract

A study of the energy accommodation of neon colliding with a crystalline self-assembled 1-decanethiol monolayer adsorbed on Au(111) is presented. The intensity and velocity dependencies of the scattered neon as a function of incident angle and energy were experimentally measured. Scattering calculations show good agreement with these results, which allows us to examine the detailed dynamics of the energy and momentum exchange at the surface. Simulation results show that interaction times are, at most, a few picoseconds. Even for these short times, energy exchange with the surface, both normal and in-plane, is very rapid. An important factor in determining the efficiency of energy exchange is the location at which the neon collides with the highly corrugated and structurally dynamic unit cell. Moreover, our combined experimental and theoretical results confirm that these are truly surface collisions in that neon penetration into the organic boundary layer does not occur, even for the highest incident energies explored, 560 meV.

Quantum-State-Resolved CO2 Scattering Dynamics at the Gas−Liquid Interface: Incident Collision Energy and Liquid Dependence

“…Similar dynamical branching into TD and IS channels has been observed for gases scattering from self-assembled monolayers (SAMs). [7][8][9][10][11][12][13] Indeed, with the advantage of well-ordered and chemically "tunable" alkyl chain scaffolding, such SAM studies offer considerable promise for the identification of important chemical and physical surface properties in the gas-liquid collision event. Furthermore, useful qualitative insight can also be obtained by comparison with molecular quantum state resolved studies of gas-solid surface scattering, for which an impressive body of experimental work currently exists from several groups.…”

Dynamics of the Reaction of O(3P) Atoms with Alkylthiol Self-assembled Monolayers

“…[13][14][15]19,22,25,[29][30][31][32][33][34][35][36] The notable gap that exists in experimental studies of reactive dynamics at SAM surfaces does not apply equally to theoretical investigations. In fact, the relative order that is present in SAM surfaces has made them attractive proxies as an alternative to the more challenging treatment of reactions on more complex liquid structures.…”

“…The same group went on to study the inelastic scattering dynamics in more detail, 33 extending their related work on inelastic scattering of closed shell species. 13,14,24,26,29,31,32,34,38 The reactive dynamics at hyperthermal energies (5 eV) have also been investigated by Schatz and Troya, 39 motivated in part by the oxidation of hydrocarbon polymers by O( 3 P) on the outer surfaces of spacecraft in low earth orbit (LEO). [40][41][42] Both sets of dynamical scattering calculations adopted mixed "QM/MM" approaches, in which the O atom and outer parts of the alkyl chain are treated quantum mechanically while the rest of the alkyl chain, sulfur atom, and gold atoms are treated by molecular mechanics.…”

“…[5][6][7] Fairbrother and co-workers have also examined the destruction of alkyl, fluorinated, and X-raymodified SAMs by a thermalized mixture of atomic and molecular oxygen (O( The first such experiment was carried out by Naaman and coworkers 10 using molecular beams of He, Ar, NO, and O 2 from alkyl and fluorinated SAMs and time-of-flight mass spectrometry (TOF-MS) to detect the scattered species. Subsequent work by Siebener and co-workers [11][12][13][14][15] and, most comprehensively, by Morris and co-workers [16][17][18][19][20][21][22][23][24][25][26] has investigated the effects of varying the identity of the impinging gas, impact angle, final angle, initial energy, monolayer temperature, SAM terminal group, alkyl chain length, and metal substrate (hence, surface density). This has led to a wealth of information on factors affecting energy transfer at the gas-SAM interface.…”

Helium atom diffraction measurements of the surface structure and vibrational dynamics of CH3–Si(111) and CD3–Si(111) surfaces

“…Several synthetic routes have allowed the fabrication of high-coverage atomic and molecular layers on a variety of metallic and semiconducting surfaces, [1][2][3][4][5] with self-assembled monolayers ͑SAMs͒ produced by thiol linkages to Au͑111͒ comprising the most ubiquitous and advanced methodology. 2,[6][7][8][9][10][11][12][13][14][15] Such SAMs have evolved into a sophisticated technology with applications in nanoscience and biotechnology. [16][17][18][19] With the success of the SAM/Au system, strategies for creating molecular layers on semiconductor substrates have been the focus of ongoing research.…”