Deciphering the Role of Noncovalent Interactions in the Conformations of Dibenzo‐1,5‐dichalcogenocines

Robin Weiss (1) , Yann Cornaton (1) , Hassan Khartabil (2) , Loïc Groslambert (1) , Eric Hénon (2) , Patrick Pale (1) , Jean-Pierre Djukic (1) , Victor Mamane (1)

1 Institut de Chimie de Strasbourg
2 ICMR - Institut de Chimie Moléculaire de Reims - UMR 7312

A combined experimental and theoretical study is reported on the new dibenzo-1,5-ditellurocine 2-Te in order to get an overview on the parameters controlling conformational change and to explain the differences with sulfur and selenium analogues. The boat to chair conformer preference is revealed by DFT calculations. For 2-Te, a G value of about 3 kJ/mol was calculated, close to the value measured by NMR (5 kJ/mol). However, DFT calculations with implicit solvation effects could not clearly establish the presence of an intramolecular Te---HC noncovalent interaction (NCI), as observed in the solid state. The Independent Gradient Model (IGM) methodology discloses an existent but probably not sufficiently discriminating Te---HC NCI. It also confirms that van der Waals interactions between phenyl rings is a source of stabilization of the boat conformer. Furthermore, electrostatic potential analysis suggests that chalcogen bonds between Te -holes and solvent might play an important role.

Domaines: Chimie organique; Catalyse; Matériaux; Chimie analytique; Chimie de coordination

Robin Weiss, Yann Cornaton, Hassan Khartabil, Loïc Groslambert, Eric Hénon, et al.. Deciphering the Role of Noncovalent Interactions in the Conformations of Dibenzo‐1,5‐dichalcogenocines. ChemPlusChem, 2022, 87, pp.e202100518. ⟨10.1002/cplu.202100518⟩. ⟨hal-03550827⟩