Two polymorphs ofN¹,N⁴-bis(5-hydroxypenta-1,3-diynyl)-N¹,N⁴-diphenylbenzene-1,4-diamine

Abstract

The title compound, C(28)H(20)N(2)O(2), forms two conformational polymorphs, (I) and (II), where the molecular structures are similar except for the orientation of the two hydroxy groups. In (I), which was obtained by slow evaporation from chloroform, the two hydroxy groups have an anti conformation. The molecules form a sheet structure within the ac plane, where the hydroxy groups form zigzag hydrogen bonds. In (II), which was obtained by slow evaporation from acetonitrile, the two hydroxy groups have a syn conformation. The molecules form a double-sheet structure within the ab plane, where the hydroxy groups form 4-helix hydrogen bonds.