Chalcogen-Nitrogen Bond: Insights into a Key Chemical Motif

Abstract

Chalcogen-nitrogen chemistry deals with systems in which sulfur, selenium, or tellurium is linked to a nitrogen nucleus. This chemical motif is a key component of different functional structures, ranging from inorganic materials and polymers, to rationally designed catalysts, to bioinspired molecules and enzymes. The formation of a selenium–nitrogen bond, typically occurring upon condensation of an amine and the unstable selenenic acid, often leading to intramolecular cyclizations, and its disruption, mainly promoted by thiols, are rather common events in organic Se-catalyzed processes. In this work, focusing on examples taken from selenium organic chemistry and biochemistry, the selenium–nitrogen bond is described, and its strength and reactivity are quantified using accurate computational methods applied to model molecular systems. The intermediate strength of the Se–N bond, which can be tuned to necessity, gives rise to significant trends when comparing it to the stronger S– and weaker Te–N bonds, reaffirming also in this context the peculiar and valuable role of selenium in chemistry and life.

Nature and Strength of the π‐Hole Chalcogen Bonded Complexes between Substituted Pyridines and SO3 Molecule

“…Moreover, a calculation at the MP2=full/aug‐cc‐pVTZ level, reports a N−S distance of 1.559 Å for N 2 S molecule. Orian studied the chalcogen‐nitrogen bond of RX−NR′ 2 complexes where X=S, Se, or Te and R and R′=H, CH 3 , and CF 3 employing ZORA‐BLYP−D3(BJ)/TZ2P level of theory [50] . They have predicted a N−S bond distances of 1.73, 1.72, 1.68, 1.74 and 1.71 Å for HS‐NH 2 , H 3 CS−N(CH 3 ) 2 , F 3 CS−N(CH 3 ) 2 , H 3 CS−N(CF 3 ) 2 and F 3 CS−N(CF 3 ) 2 respectively.…”

Mechanistic Insight into SARS-CoV-2 Mpro Inhibition by Organoselenides: The Ebselen Case Study

“…Thus, efforts are prompted to design selenium-based systems able to reach the target protein with the N-Se bond still intact. This requires a finetuning of the N-Se bond, designing ad hoc molecular features [58] to prevent ring-opening in the presence of free cysteines such as those present in the serum, preserving the ability of N-Se bond activation in the target proteins.…”

Synthesis of new chiral N-heterocyclic diselenides and their application in the alkoxyselenylation reaction

“…30–34 On the other hand, most derivatives contain a heteroatom in the vicinity of Se which enhances selectivity in asymmetric transformations and is crucial for their biological activity. 14,35…”

“…[30][31][32][33][34] On the other hand, most derivatives contain a heteroatom in the vicinity of Se which enhances selectivity in asymmetric transformations and is crucial for their biological activity. 14,35 In our previous paper, we reported on the synthesis and configuration assignment of an enantiopure diselenide based on a bicyclic, N-heterocyclic backbone 1 (Fig. 2).…”