Compression and caging of CD3Cl by H2O layers on Ru(001)

Abstract

Dipole-dipole interactions among CH 3 Cl molecules on Ru (001): Correlation between work function change and thermal desorption studies

Electron-driven chemistry of halogenated compounds in condensed phases: Effects of solvent matrices on reaction dynamics and kinetics

“…inhibition of Freon desorption by a water ice overlayer) has been observed earlier for halocarbons (CCl 4 [93], CD 3 Cl [113], CF 2 Cl 2 [37]), N 2 [114] and SF 6 [71] under thick water overlayers, where the release of the trapped molecules occurs spontaneously in a very narrow temperature range (several degrees K) corresponding to ASW crystallization. This phenomenon is known as 'molecular volcano' desorption [93].…”

Electron-induced chemistry of methyl chloride caged within amorphous solid water

“…The first at 115 K corresponds to molecules adsorbed at the ASWvacuum interface and is not affected by the total ASW layer thickness. 6 Binding energy analysis suggests that the adsorption site associated with the 115 K desorption peak has a binding energy of 7.5 ± 0.15 kcal/mole, assuming that the preexponential factor for desorption equals 10 13 s −1 . The fact that the remaining desorption peaks appear at higher temperatures (165 K and 195 K) implies that these molecules reside deeper within the ASW bulk.…”

“…[1][2][3][4][5][6][7] In model laboratory studies electrons may originate indirectly from photo-induced processes 8 or from a well defined electron gun source. [9][10][11][12] The motivation for such studies arises from the need to better understand the physics and chemistry at the outer space 13 as well as phenomena occurring at the stratosphere, 14 where solid particles are covered by layers of ice.…”

“…20 As previously reported by our lab the photochemistry of caged organic molecules within the ASW film reveals rich chemistry upon UV irradiation. 6,21 This photo-reactivity is explained by the confinement (trapping) of organic molecules within ASW (Caging phenomenon) as hot photo excited electrons are injected from the metal substrate onto the ASW film. Methyl 6 and ethyl 21 chlorides were studied in our group as dipolar probe molecules.…”

“…If the dipolar organic molecules are first deposited on the substrate followed by water adsorption, a compression process of the preadsorbed molecules takes place that is completed at around 20 monolayer (ML) of ASW when molecules are caged in the formation of a micelle like structure. 6,22,23 This cage has a unique and distinctive Thermal Programmed Desorption (TPD) spectrum, typically composed of two desorption peaks. The first peak is characterized by a very narrow (2-3 K wide) peak near the ASW to crystalline ice transition at 165 K, as reported for the first time for nitrogen 24 and subsequently for many other gasses, becoming the volcano desorption.…”