Spatial quenching of a molecular charge-transfer process in a quantum fluid: the Cs_x–C₆₀reaction in superfluid helium nanodroplets

Abstract

A recent experimental study [Renzler et al., J. Chem. Phys., 2016, 145, 181101] on superfluid helium nanodroplets reported different reactivities for Cs atoms and Cs dimers with C fullerenes inside helium droplets. Alkali metal atoms and clusters are heliophobic, therefore typically residing on the droplet surface, while fullerenes are fully immersed into the droplet. In this theoretical study, which combines standard methods of computational chemistry with orbital-free helium density functional theory, we show that the experimental findings can be interpreted in the light of a quenched electron-transfer reaction between the fullerene and the alkali dopant, which is additionally hindered by a reaction barrier stemming from the necessary extrusion of helium upon approach of the two reactants.

Electron ionization of helium droplets containing C60 and alcohol clusters

“…15,16 However, this poses a challenge, since one must find a way to combine ionized C 60 and methanol molecules at low temperature. Here we approach this problem by trapping the neutral molecules in liquid helium nanodroplets and then ionizing the system using electron ionization.…”

Spectroscopy of a rotating hydrogen molecule in carbon nanotubes

“…The parameters of the APPM were extracted by fitting to SAPT(DFT)-based values of dispersionless and dispersion terms. This APPM is specially designed to characterize the interaction of adsorbates with curved carbon-based nanostruc-tures 5,8,23 and metallic solid surfaces. 48 It should be stressed that the influence of the nanotube curvature-induced dipole 49 in the H 2 -CNT interaction is implicitly accounted for in the potential model through the dependence of dispersionless and dispersion components on the angle between the radial vector going from the nanotube center to one carbon atom and the vector pointing from the H 2 center-of-mass to the same C atom.…”

“…Ab-initio intermolecular interaction theory allows an accurate description of van der Waals (vdW)-dominated interactions of molecules with carbon nanostructures. 7,8,[16][17][18][19][20][21][22][23] Recent options are mixed schemes combining second-order Möller-Plesset perturbation theory with the coupled-cluster approach, 16,17 as well as non-periodic implementations of the incremental method 24 applied at coupled-cluster level [25][26][27][28][29] with periodic calculations using dispersionless density functional theory. 28,[30][31][32] An alternative methodological protocol 8 combines DFT-based symmetry-adapted perturbation theory (SAPT), which is used to derive the parameters of potential models describing the gas adsorption to the carbon material, with an ad hoc-developed adsorbate wave function treatment.…”

Ab initio modelling of molecular hydrogen rotation in the outside of carbon nanotubes

“…Our method is based on a potential model for the van der Waals (vdW)-dominated H 2nanotube interaction relying on ab-initio DFT-based symmetry-adapted perturbation theory (SAPT) to derive the parameters of an effective pairwise potential model [4,8]. In fact, ab-initio intermolecular interaction theory has recently allowed an accurate description of dispersion-dominated interactions of molecules with carbon nanostructures [7,8,[17][18][19][20][21][22][23][24]. Recent options include schemes combining second-order Möller-Plesset perturbation theory with the coupled-cluster approach [17,18], as well as a non-periodic implementation of the incremental method [25] applied at coupled-cluster level [26][27][28][29][30] with periodic calculations employing dispersionless density functional theory [29,[31][32][33].…”