Crystal Structures of Organoselenium Compounds: Structural Descriptors for Chalcogen Bonds

Abstract

Less conventional non-covalent interactions such as chalcogen bonds attract the attention of researchers in various fields (organocatalysis, material sciences, biological chemistry, …). We present here useful descriptors to easily discriminate the structures in which chalcogen bonds involving selenium are observed. Our study focused on organoselenium compounds as chalcogen bond donors and on molecular entities, as chalcogen bond acceptors, containing N, O, S, Se and Te atoms or aromatic rings. For conventional chalcogen bonds (C-Se⋯X, with X = N, O, S, Se, or Te), the combination of the C-Se⋯X angle and the distance between X and the C-Se-C plane proved to be most relevant for identification of chalcogen bonds. For chalcogen⋯π bonds, the most relevant parameters are a combination of the C-Se⋯X angle and the angle between the C-Se bond and the normal to the aromatic ring plane.

A Structural Approach to the Strength Evaluation of Linear Chalcogen Bonds

“…ChB acceptors are nucleophiles with Lp-bearing atoms and anions, in which the A atom directly involved in ChB is typically either a pnictogen (usually nitrogen), another chalcogen, or a halogen atom. Unsaturated systems in which the ChB acceptor is a multiple bond or an aromatic moiety will not be examined here, and the reader is referred to specific publications for an overview of this topic [ 31 , 32 , 33 , 34 , 35 ].…”