Crystal structures of (Z)-5-[2-(benzo[b]thiophen-2-yl)-1-(3,5-dimethoxyphenyl)ethenyl]-1H-tetrazole and (Z)-5-[2-(benzo[b]thiophen-3-yl)-1-(3,4,5-trimethoxyphenyl)ethenyl]-1H-tetrazole

(Z)-5-[2-(Benzo[b]thiophen-2-yl)-1-(3,5-dimethoxyphenyl)ethenyl]-1H-tetrazole methanol monosolvate, C19H16N4O2S CH3OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,5-dimethoxyphenyl)acrylonitrile with tributyltin azide via a [3 + 2]cycloaddition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thiophen-3-yl)-1-(3,4,5-trimethoxyphenyl)ethenyl]-1H-tetrazole, C20H18N4O3S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-3-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with tributyltin azide. Crystals of (I) have two molecules in the asymmetric unit (Z′ = 2), whereas crystals of (II) have Z′ = 1. The benzothiophene rings in (I) and (II) are almost planar, with r.m.s deviations from the mean plane of 0.0084 and 0.0037A in (I) and 0.0084A in (II). The tetrazole rings of (I) and (II) make dihedral angles with the mean planes of the benzothiophene rings of 88.81(13) and 88.92(13)° in (I), and 60.94(6)° in (II). The dimethoxyphenyl and trimethoxyphenyl rings make dihedral angles with the benzothiophene rings of 23.91(8) and 24.99(8)° in (I) and 84.47(3)° in (II). In both structures, molecules are linked into hydrogen-bonded chains. In (I), these chains involve both tetrazole and methanol, and are parallel to the b axis. In (II), molecules are linked into chains parallel to the a axis by N - H⋯N hydrogen bonds between adjacent tetrazole rings.