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(8)H(8)Cl(2)N(4)O·2H(2)O, (I), triclinic (E)-4-(2-{[amino(iminio)methyl]amino}vinyl)-3,5-dichlorophenolate methanol disolvate, C(8)H(8)Cl(2)N(4)O·2CH(4)O, (II), and orthorhombic (E)-amino[(2,6-dichloro-4-hydroxystyryl)amino]methaniminium acetate, C(8)H(9)Cl(2)N(4)O(+)·C(2)H(3)O(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 hydrogen-bond-formation ability of the solvents, the hydrogen-bonding arrangements vary in the three forms.

Polymorphism in 2-(4-hydroxy-2,6-dimethylanilino)-5,6-dihydro-4H-1,3-thiazin-3-ium chloride.

Details of the structures of two conformational polymorphs of the title compound, C(12)H(17)N(2)OS(+)·Cl(-), are reported. In form (I) (space group P-1), the two N-H groups of the cation are in a trans conformation, while in form (II) (space group P2(1)/c), they are in a cis arrangement. This results in different packing and hydrogen-bond arrangements in the two forms, both of which have extended chains lying along the a direction. In form (I), these chains are composed of centrosymmetric R(4)(2)(18) (N-H...Cl and O-H...Cl) hydrogen-bonded rings and R(2)(2)(18) (N-H...O) hydrogen-bonded rings. In form (II), the chains are formed by centrosymmetric R(4)(2)(18) (N-H...Cl and O-H...Cl) hydrogen-bonded rings and by R(4)(2)(12) (N-H...Cl) hydrogen-bonded rings.