Crystal structure of isobutyramide and comparison with its conformation in chloroform solution as observed from lanthanide-induced nuclear magnetic resonance shifts

Abstract

The crystal structure of isobutyramide has been determined by X-ray diffraction. Crystals are monoclinic, space group P2₁/c, with a= 10.356(6), b= 5.990(4), c= 9.663(6)Å, β= 108.10(5)°, Z= 4. The structure was solved by direct methods and refined to R 7.6%. In the crystal, the C–H bond is anti to the CO bond, with H–C–CO 180°. In solution, the lanthanide-induced n.m.r. spectra show that the anti- and the syn-conformations of the amide group are both present.