10-(4-Fluoro­benzyl­idene)­anthrone

The title compound, C₂₁H₁₃FO, was prepared from anthrone and 4-fluoro­benz­aldehyde. The central six-membered ring has an asymmetric boat conformation, in which the carbonyl C and the opposite C atom deviate from the plane of the other four atoms by 0.173 (2) and 0.319 (2) Å, respectively.

3,6-Di­phenyl-1,4-bis­(p-tolylsulfonyl)-1,4-di­hydro-1,2,4,5-tetrazine

The central six-membered ring of the title compound, C₂₈H₂₄N₄O₄S₂, has a boat conformation, in which the N atoms bonded to sulfonyl groups deviate from the plane of the other four atoms by 0.389 (4) and 0.343 (4) Å.

Di­phenyl 3,6-bis(4-chloro­phenyl)-1,2-di­hydro-1,2,4,5-tetrazine-1,2-di­carboxyl­ate

The title compound, C₂₈H₁₈Cl₂N₄O₄, was prepared by the reaction of phenyl chloro­formate and 3,6-bis(4-chloro­phenyl)-1,4-di­hydro-1,2,4,5-tetrazine. The structural identity, confirmed by crystal structure determination, revealed a re-arrangement, resulting in formation of the 1,2-di­hydro­tetrazine derivative from the starting materials. The central tetrazine ring adopts a twist conformation.

10-(3,4-Dimethoxy­benzyl­idene)anthrone

The title compound, C₂₃H₁₈O₃, was prepared from anthrone and 3,4-dimethoxy­benzaldehyde in the presence of pyridine. X-ray analysis shows that the three rings of the anthraquinone moiety are not coplanar; the central six-membered ring assumes an asymmetric boat conformation in which the carbonyl C and the opposite C atom deviate from the plane by 0.190 (3) and 0.262 (3) Å, respectively.