Thermal conversion of a pyridine solvate to a de-solvate facilitated by rearrangement of chalcogen bonds. The solvate and non-solvate structures ofN-(2-nitro-4-(3-oxobenzo[d][1,2]selenazol-2(3H)-yl)phenyl)picolinamide

Abstract

The pyridine solvate of benzisoselenazolinone 1.pyridine is characterised by planar sheets of the benzisoselenazolinone 1 pierced by channels of pyridine molecules at an angle of 133°, the pyridine molecules are held in place by N⋯Se chalcogen bonding to the isoselenazolinone moiety. These channels, which extend through the structure to the surface of the crystal, provide a means for escape of pyridine from the lattice when the crystal is heated to ca. 100 °C. Upon loss of the pyridine from these channels the remaining molecules undergo rearrangement to fill the space and in doing so the N⋯Se chalcogen bond in 1.pyridine is replaced by a C[double bond, length as m-dash]O⋯Se chalcogen bond to..