Synthesis and crystal structure of 5-methyl-5,10-dihydrophenarsazine

The X-ray crystal structure of 5-methyl-5,10-dihydrophenarsazine, C₁₃H₁₂NAs, has been determined. The crystals are orthorhombic, space group P2₁2₁2₁, a = 8.511(4), b = 5.690(1), c = 23.535(9) Å, V = 1139.7(1.0)A³, and Z = 4. Least-squares refinement converged to R = 0.049 and Rw = 0.045. The central ring is in a boat conformation and the 5-methyl group is in the axial position with respect to the central ring. The folding angle between the planes of the two benzo rings is 154.1(4)°.