Catching the role of anisotropic electronic distribution and charge transfer in halogen bonded complexes of noble gases

• DOI: 10.1063/1.4919692
• Publication Date: 2015-05-11T17:00:16Z
• Authors: Alessio Bartocci; Leonardo Belpassi; David Cappelletti; Stefano Falcinelli; Felice Grandinetti; Francesco Tarantelli; Fernando Pirani
• Keywords: Noble gas

The systems studied in this work are gas-phase weakly bound adducts of the noble-gas (Ng) atoms with CCl4 and CF4. Their investigation was motivated by widespread current interest for intermolecular halogen bonding (XB), a structural motif recognized to play role fields ranging from elementary processes biochemistry. simulation static dynamic behaviors complex featuring XB requires formulation reliable accurate model potentials, whose development relies on detailed characterization strength nature interactions occurring simple exemplary halogenated systems. We thus selected prototypical Ng-CCl4 Ng-CF4 performed high-resolution molecular beam scattering experiments measure absolute scale their high sensitivity. In general, we expected probe typical van der Waals interactions, consisting combination size (exchange) repulsion dispersion/induction attraction. For He/Ne-CF4, analysis glory quantum interference pattern, observable velocity dependence integral cross section, confirmed indeed expectation. On other hand, He/Ne/Ar-CCl4, data unravelled much deeper potential wells, particularly certain configurations interacting partners. experimental can be properly reproduced only including shifting repulsive wall at shorter distances, accompanied an increased dispersion attraction, additional short-range stabilization component. To put these findings firmer ground, performed, geometries complexes, theoretical calculations aimed evaluate interaction effects formation electron charge density constituting moieties. It ascertained that adjustments suggested actually reflect two chemically meaningful contributions, namely, stabilizing arising anisotropy distribution around Cl atom stereospecific transfer occurs distances mainly probed experiments. Our suggest largest effect is vertex geometry while appear minor negligible role.