X-ray structure investigation of 1-acetoxy-1-cyano-2-naphthylethylene and 1,1-dicyano-2-naphthylethylene

The crystal structures of 1-acetoxy-1-cyano-2-naphthylethylene (I) and 1,1-dicyano-2-naphthylethylene (II) are determined by X-ray structure analysis. Crystals I are monoclinic; at 25° C, the unit cell parameters are as follows: a = 17.308(6) Å, b = 4.507(1) Å, c = 17.845(5) Å, β = 107.90(2)°, V = 1324.7(7) ų, d _calcd = 1.260 g/cm³, Z = 4, and space group P2₁/n. Crystals II are monoclinic; at 25°C, the unit cell parameters are a = 3.827(1) Å, b = 15.784(4) Å, c = 17.226(2) Å, β = 91.22(2)°, V = 1040.3(4) ų, d _calcd = 1.304 g/cm³, Z = 4, and space group P2₁/n. It is revealed that, in crystal structures of I and II, the molecular stacks characteristic of compounds of this series are formed through stacking contacts along the direction of the smallest lattice parameter.