Solvatomorphism in (E)-2-(2,6-dichloro-4-hydroxybenzylidene) hydrazinecarboximidamide

The structures of orthorhombic (E)-4-(2-{[amino(iminio)- methyl]amino}vinyl)-3,5-dichlorophenolate dihydrate, C ₈H ₈- Cl ₂N ₄O·2H ₂O, (I), triclinic (E)-4-(2-{[amino(iminio)methyl]- amino}vinyl)-3,5-dichlorophenolate methanol disolvate, C ₈H ₈-Cl ₂N ₄O· 2CH ₄O, (II), and orthorhombic (E)-amino[(2,6-dichloro- 4-hydroxystyryl)amino]methaniminium acetate, C ₈H ₉-Cl ₂N ₄O ⁺·C ₂H ₃O ₂ ^-, (III), all crystallize with one formula unit in the asymmetric unit, with the molecule in an E configuration and the phenol H atom transferred to the guanidine N atom. Although the molecules of the title compounds form extended chains via hydrogen bonding in all three forms, owing to the presence of different solvent molecules, those chains are connected differently in the individual forms. In (II), the molecules are all coplanar, while in (I) and (III), adjacent molecules are tilted relative to one another to varying degrees. Also, because of the variation in hydrogenbond- formation ability of the solvents, the hydrogen-bonding arrangements vary in the three forms.