New insights into chalcogen bonding provided by co-crystal structures of benzisoselenazolinone derivatives and nitrogen bases

Abstract

A number of derivatives of benzisoselenazolinones, including the drug ebselen, have been synthesized, and their interactions with various nitrogen bases characterized through X-ray crystallography. Structural studies revealed a strong interaction in all cases, with Se⋯N distances well within the Van der Waals radii of the constituent atoms. We suggest that there is a significant charge transfer component to this interaction, in contrast to some other interactions of similar strength and directionality. We have also found that this interaction can be enhanced via H-bonding to the carbonyl group of the benzisoselenazolinone moiety.