Structures, charge distributions, and dynamical properties of weakly bound complexes of aromatic molecules in their ground and electronically excited states

Abstract

Abstract.Complexes or clusters are non-covalently bound assemblies of two or more molecules that are held together by hydrogen bonding, van der Waals interactions, and other weak forces. The derived values of the rotational constants can be used to determine the structures of such species, in both their ground and electronically excited states. Some species exhibit different structures in the two states, owing to photon-induced changes in their electronic distributions. Evidence for the motion of one species relative to another along some intermolecular coordinate also is observed in some cases. We describe the application of these techniques to nitrogen and water complexes of p-difluorobenzene and Ar and water complexes of indole and azaindole, as models of hydrophobic and hydrophilic interactions. These studies have provided detailed information about how the electronic charge distributions of the species interact, how the structures of the individual species are modified when they interact, and how the properties of the complex are different from its component parts.iv

Effect of Noncovalent Interactions on Vibronic Transitions: An Experimental and Theoretical Study of the C2H⋅⋅⋅CO2 Complex

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Conformational Stability of the Propylene Oxide−Water Adduct: Direct Spectroscopic Detection of O−H···O Hydrogen Bonded Conformers

“…In particular, the interactions between water and chiral molecules are of significant interest since hydrogen bonding governs the solvation processes in the aqueous environments . In recent years, jet-cooled high resolution spectroscopy has been successfully applied to study a number of water-organic molecule adducts such as benzene-water, phenol-water, ethylene oxide (EO)-water, oxetane-water, and tetrahydrothiophene-water . These studies provided detailed and precise information about the structures and dynamics of these hydrogen bonded systems.…”

Active learning of potential-energy surfaces of weakly bound complexes with regression-tree ensembles

“…4 They offer an appealing way for the quantitative investigations of the effects of hydration on the photoexcitation and ionization dynamics and the mechanisms of chemical reactions in general. [5][6][7][8][9][10] First principles calculations of potential energy surfaces (PESs) for weakly-bound complexes are challenging and computationally expensive. [11][12][13][14] The presence of small energy differences in weakly-bound PES means that generally high levels of theory need to be employed to produce correct asymptotic behavior.…”