Folded conformations. Part VII. Crystal and molecular structure of NN′-[bis-(α-tosylbenzyl)] urea acetone solvate. Comparison between solution and solid-state conformation

Abstract

The crystal and molecular structure at –160 °C of the title compound has been determined by direct methods from diffractometer data. Crystals are monoclinic. a= 10.869(10), b= 22.741 (21), c= 13.124(6)Å, β= 110.22°(6), space group P2₁/c, Z= 4. The structure was refined by anisotropic least-squares to R 0.088 for 4 085 independent reflections. The molecule resides in a folded conformation in which the hydrogen atoms attached to both nitrogen atoms are hydrogen bonded to one molecule of acetone of crystallization. The conformation is similar to that favoured in solution, although in the latter the position of acetone is uncertain. On the basis of empirical potentialenergy calculations, we suggest that conformational preferences are caused by non-bonded repulsive interactions.