organic compounds
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In the title compound, C21H11N5S, the phenothiazine unit has a butterfly structure, and the central six-membered ring adopts a boat conformation. The dihedral angle between the benzene rings is 127.64 (6)°, which is smaller than those reported for similar compounds because of the steric repulsion between the phenothiazine and its tetracyano-1,3-butadiene substituent. The dicyanovinyl groups are almost orthogonal to one another, making a dihedral angle of 80.58 (6)°. In the crystal, the molecules are aligned along the b axis. Four kinds of weak C—HN interactions are recognized, one of which connects the molecules into a one-dimensional array and the remaining three link these arrays.