Abstract
This paper reports for the first time molecular beam experiments for the scattering of He, Ne, and Ar by the Br2 molecule, with the aim of probing in detail the intermolecular interaction. Measurements have been performed under the experimental condition to resolve the glory pattern, a quantum interference effect observable in the collision velocity dependence of the integral cross section. We analyzed the experimental data with a reliable potential model defined as a combination of an anisotropic van der Waals component with the additional contribution due to charge transfer and polar flattening effects related to the formation of an intermolecular halogen bond. The model involves few parameters, whose values are related to fundamental physical properties of the interacting partners, and it allows an internally consistent comparison of the stability of the gas-phase adducts formed by Br2 moiety with different noble gases as well as homologous complexes with the Cl2 molecule. The same model appears to be also easily generalized to describe the interaction of diatomic halogen molecules in the excited B(3Π) electronic state where the halogen bond contribution tends to vanish and more anisotropic van der Waals components dominate the structure of the complexes with noble gases.
Highlights
IntroductionIn order to disentangle the effect of the XB on the molecular dynamics, it is necessary to identify the interaction components involved and to provide their radial and angular dependences
The knowledge of the nature and the characterization of the role of the intermolecular halogen bond (XB) is presently recognized to be of great relevance in many areas of fundamental and applied research, including materials engineering, biochemistry, molecular recognition, drug design, and supra-molecular Chemistry (Gilday et al, 2015; Han et al, 2017).In order to disentangle the effect of the XB on the molecular dynamics, it is necessary to identify the interaction components involved and to provide their radial and angular dependences
As for noble gas (Ng)–Cl2 systems, we have found that X groundstate potential energy surfaces (PES) in Ng–Br2 adducts is mainly determined by anisotropic halogen bond components, concurring to stabilize selectively the collinear configuration by charge transfer (CT) and polar flattening (PF) effects
Summary
In order to disentangle the effect of the XB on the molecular dynamics, it is necessary to identify the interaction components involved and to provide their radial and angular dependences This information, seldom available in the literature, can obtained by investigating in detail prototypical systems, whose features are necessary to formulate interaction models useful for the description of the force fields in systems at increasing complexity and of applied interest (Cappelletti et al, 2015). The weakly bound complexes Ng–X2, formed by a noble gas (Ng) and a di-halogen molecule X2 (X=Cl, Br, I), have been considered as prototypes of particular relevance for investigating energy transfer mechanisms and for the characterization of the fundamental role of the intermolecular. Extensive spectroscopic and theoretical studies (see, for instance, Jahn et al, 1996; Buchachenko et al, 2000; Prosmiti et al, 2002a,b; de Lara-Castells et al, 2004; Boucher et al, 2005; Garcia-Vela, 2005; Carrillo-Bohórquez et al, 2016) have been devoted to the characterization of the stability of the Ng–Br2 adducts in the limiting collinear and T-shaped configurations and of the predissociation dynamics induced by electronic, vibrational, and rotational excitations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
