Crystal and molecular structure of 5-5′ biisoxazole*

Abstract

Abstract The crystal structure of 5-5′ biisoxazole has been determined from x-ray diffraction data. The crystals are triclinic with two molecules in a unit cell of dimensions a = 10.47 Å, b = 9.01 Å, c = 3.78 Å, α = 75°58′, β = 115°46′, γ = 90°51′; space group P[unk]. The structure was determined by trial and the parameters were refined by least squares and differential synthesis. The final R value for the observed 584 reflections is 0.117. The molecule has a trans configuration and is planar. Bond lengths and angles are closely similar to those found in 3-3′ biisoxazole. Some values of the intermolecular distances are very close to the van der Waals limits.