Mol-ecular and crystal structure of 5,9-dimethyl-5H-pyrano[3,2-c:5,6-c']bis-[2,1-benzo-thia-zin]-7(9H)-one 6,6,8,8-tetroxide di-methyl-formamide monosolvate.

The title mol-ecule crystallizes as a di-methyl-formamide monosolvate, C19H14N2O6S2·C3H7NO. The mol-ecule was expected to adopt mirror symmetry but slightly different conformational characteristics of the condensed benzo-thia-zine ring lead to point group symmetry 1. In the crystal, mol-ecules form two types of stacking dimers with distances of 3.464 (2) Å and 3.528 (2) Å between π-systems. As a result, columns extending parallel to [100] are formed, which are connected to inter-mediate di-methyl-formamide solvent mol-ecules by C-H⋯O inter-actions.