The crystal structure of 3′‐methoxy‐5‐phenyl‐5,10‐dihydrophenarsazine, C 19 H 16 AsNO

The crystal structure of 3′‐methoxy‐5‐phenyl‐5,10‐dihydrophenarsazine, C 19 H 16 AsNO has been determined by the single crystal x‐ray diffraction method. The crystals are monoclinic with a = 15.305(6), b = 5.809(2), c = 17.595(6)Å, β = 92.92(2)°, V = 1562.3(1.0Å 3 , space group P2,/n, Z = 4 and d calc = 1.485g cm −3 . An automatic diffractometer with graphite monochromatized MoKα radiation was used to obtain 1480 observed reflection with I > 3σ(I) at 2θ < 50°. Final R = 0.040 and wR = 0.032. The tricyclic ring is folded with the central ring in a flattened boat conformation. The folding angle between the least‐squares planes of the two benzo rings is 164.6(2)°. The 3′‐methoxyphenyl group is in a boat‐axial conformation with respect to the central ring.