Interactions of benzene, naphthalene, and azulene with alkali-metal and alkaline-earth-metal atoms for ultracold studies

Abstract

We consider collisional properties of polyatomic aromatic hydrocarbon molecules immersed into ultracold atomic gases and investigate intermolecular interactions of exemplary benzene, naphthalene, and azulene with alkali-metal (Li, Na, K, Rb, Cs) and alkaline-earth-metal (Mg, Ca, Sr, Ba) atoms. We apply the stateof-the-art ab initio techniques to compute the potential energy surfaces (PESs). We use the coupled cluster method restricted to single, double, and noniterative triple excitations to reproduce the correlation energy and the small-core energy-consistent pseudopotentials to model the scalar relativistic effects in heavier metal atoms. We also report the leading long-range isotropic and anisotropic dispersion and induction interaction coefficients. The PESs are characterized in detail and the nature of intermolecular interactions is analyzed and benchmarked using symmetry-adapted perturbation theory. The full three-dimensional PESs are provided for selected systems within the atom-bond pairwise additive representation and can be employed in scattering calculations. Presented study of the electronic structure is the first step towards the evaluation of prospects for sympathetic cooling of polyatomic aromatic molecules with ultracold atoms. We suggest azulene, an isomer of naphthalene which possesses a significant permanent electric dipole moment and optical transitions in the visible range, as a promising candidate for electric field manipulation and buffer-gas or sympathetic cooling.

Variation of the Fine-Structure Constant in Model Systems for Singlet Fission

“…In addition to crystalline organic semiconductor materials derived from the acene family of molecules discussed herein, covalently linked dimers are also conceivable as suitable candidate systems. Anticipating further progress in cooling of polyatomic molecules with lasers − or other techniques for obtained cold polyatomic molecules, one might also envision molecules stored in optical lattices, in which intermolecular interactions can specifically be tailored, as potential probes in the future.…”

Trapping Ca+ inside a molecular cavity: computational study of the potential energy surfaces for Ca+-[n]cycloparaphenylene, n = 5–12

“…24 There are several previous studies of alkali metal ions interacting with benzene, as they form a prototypical system that is sensitive to polarization and dispersion of the benzene p electron cloud. [25][26][27] In particular, a recent study by Savarese et al compared a range of computational methods and dispersion corrections on Li + -benzene complexes and showed that for some methods, such as DFT B3LYP, the inclusion of an empirical dispersion correction resulted in qualitative and quantitative differences from the reference CCSD(T) complete basis set (CBS) 28 limit. 29 This result prompted us to study the M + -benzene (Bz) complex using computational methods capable of being extended to the large nanohoop cavities.…”

Reaction of electrons trapped in cryogenic matrices with benzophenone

“…[ 15–17 ] The reaction of aromatic hydrocarbons with alkali metals has long been recognized to yield aromatic radical anions. [ 18,19 ] These radical anions are usually short‐lived reactive intermediates that are synthetically useful in a variety of organic and organometallic reactions as strong reductants. [ 20–22 ]…”

“…[15][16][17] The reaction of aromatic hydrocarbons with alkali metals has long been recognized to yield aromatic radical anions. [18,19] These radical anions are usually short-lived reactive intermediates that are synthetically useful in a variety of organic and organometallic reactions as strong reductants. [20][21][22] Benzophenone in its lowest excited state plays an important role in a variety of photochemical reactions and is known to be highly electrophilic.…”