The crystal structures of two isomers of 5-(phenyl-iso-thia-zol-yl)-1,3,4-oxa-thia-zol-2-one.

ABSTRACT: The syntheses and crystal structures of two isomers of phenyl iso-thia-zolyl oxa-thia-zolone, C₁₁H₆N₂O₂S₂, are described [systematic names: 5-(3-phenyl-iso-thia-zol-5-yl)-1,3,4-oxa-thia-zol-2-one, (I), and 5-(3-phenyl-iso-thia-zol-4-yl)-1,3,4-oxa-thia-zol-2-one, (II)]. There are two almost planar (r.m.s. deviations = 0.032 and 0.063?Å) mol-ecules of isomer (I) in the asymmetric unit, which form centrosymmetric tetra-mers linked by strong S?N [3.072?(2)?Å] and S?O contacts [3.089?(1)?Å]. The tetra-mers are ?-stacked parallel to the a-axis direction. The single mol-ecule in the asymmetric unit of isomer (II) is twisted into a non-planar conformation by steric repulsion [dihedral angles between the central iso-thia-zolyl ring and the pendant oxa-thia-zolone and phenyl rings are 13.27?(6) and 61.18?(7)°, respectively], which disrupts the ?-conjugation between the heteroaromatic iso-thia-zoloyl ring and the non-aromatic oxa-thia-zolone heterocycle. In the crystal of isomer (II), the strong S?O [3.020?(1)?Å] and S?C contacts [3.299?(2)?Å] and the non-planar structure of the mol-ecule lead to a form of ?-stacking not observed in isomer (I) or other oxa-thia-zolone derivatives.

SUBMITTER: Zhu S 

PROVIDER: S-EPMC5683500 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature