engleski

Solvent-induced polymorphism of 2-[(2-amino-phenylimino)-phenyl-methyl]-phenol

The title compound C_19H_16N_2O crystallize as either triclinic or monoclinic polymorph depending on the solvent used. Polymorph [1] crystallizes from methanol in the space group P -1 with unit cell dimensions: a=8.723(2), b=9.344(2), c=10.544(2) Å ; alpha=71.54(2), beta=78.74(2), gamma=74.15(2)^o, and Z=2. Polymorph [2] crystallizes from benzene with space group P21/n with unit cell dimensions: a=10.230(3), b=20.536(7), c=14.563(4) Å ; beta=97.14(3)^o, and Z=8. The only similarity between molecules of [1] and two independent molecules of [2] can be found in almost co-planar phenyl moiety with chelate ring. Both structures are characterized with strong intramolecular O-H• • • N hydrogen bond. Whereas the molecular interconnections in [2] are based on van der Waals attractions between discrete molecules, molecules of [1] associate in dimers via intermolecular N-H• • • O hydrogen bonding by the operation of crystallographic centre of inversion.

Solvent-induced polymorphism; Schiff bases; X-ray analysis; Hydrogen bond; Dimmer

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