Accurate spectroscopic characterization of molecular complexes as a first step toward the understanding of intermolecular interactions

Noncovalent interactions play a key role in several biological and technological processes, yet their characterization and interpretation are still far from being satisfactory. Integrated experimental and computational investigations of molecular complexes can play an invaluable to understand the properties of intermolecular interactions.
In the past decade, many gas-phase spectroscopic investigations have focused on the understanding of the nature of weak interactions in model systems, and a great effort has been devoted – for example – to studies dealing with complexes formed by small biomolecules with either water or other solvents. In this connection, molecular complexes involving hydrogen bonding between nitrogen-containing systems can be considered as prototypes for studying the (N-H...N) interaction in biological systems [1].
Along with the well-established hydrogen bonds, emerging classes of noncovalent interactions are attracting increasing attention, such as those involving a pnicogen or chalcogen atom [2,3] because of the fundamental role they play in different fields such as catalysis, drug design, self-assembly processes, and crystal packing. Understanding the mechanisms at the basis of these technological processes requires the characterization of the directionality, strength, and nature of such interactions as well as a comprehensive analysis of their competition with other noncovalent bonds, also taking into account the tuning of these properties by different environments.

[1] L. Spada, N. Tasinato, F. Vazart, V. Barone, W. Caminati, C. Puzzarini, Chem. Eur. J. 23, 4876 (2017).
[2] W. Li, L. Spada, N. Tasinato, S. Rampino, L. Evangelisti, A. Gualandi, P. G. Cozzi, S. Melandri, V. Barone, C. Puzzarini, Angew. Chem. Int. Ed. 57, 13853 (2018).
[3] D. A. Obenchain, L. Spada, S. Alessandrini, S. Rampino, S. Herbers, N. Tasinato, M. Mendolicchio, P. Kraus, J. Gauss, C. Puzzarini, J.-U. Grabow, V. Barone, Angew. Chem. Int. Ed. 57, 15822 (2018).