Crystal structures of 5,50-bis(hydroxymethyl)-3,30-biisoxazole and 4,40,5,50-tetrakis(hydroxymethyl)-3,30-biisoxazole

Abstract

The molecular structure of 5,50-bis(hydroxymethyl)-3,30-biisoxazole, C8H8N2O4 (1), is composed of two trans planar isoxazole rings [r.m.s deviation = 0.006 (1) Å], each connected with a methyl hydroxyl group. Similarly, the structure of 4,40,5,50-tetrakis(hydroxymethyl)-3,30-biisoxazole, C10H12N2O6 (2), is composed of two planar isoxazole rings [r.m.s. deviation = 0.002 (1) Å], but with four hydroxymethyl groups as substituents. Both molecules sit on a center of inversion, thus Z0 = 0.5. The crystal structures are stabilized by networks of O-H N [for (1)] and O-H O hydrogen-bonding interactions [for (2)], giving rise to corrugated supramolecular planes. The isoxazole rings are packed in a slip-stacked fashion, with centroid-to-centroid distances of 4.0652 (1) Å for (1) (along the b-axis direction) and of 4.5379 (Å) for (2) (along the a-axis direction).