CRYSTAL AND MOLECULAR-STRUCTURE OF N-VINYLCAPROLACTAM

The X-ray crystal and molecular structure of N-vinylcaprolactam C8H13N O is determined. The compound is the initial monomer for a water-solub le polymer with a low critical temperature of dissolving (36-37 degree s C). The crystals are triclinic; a = 8.170(4), b = 8.094(4), and c = 6.799(4) Angstrom; alpha = 99.92(1)degrees, beta = 88.89(1)degrees, an d gamma = 115.30(1)degrees; sp. gr. P (1) over bar; CuKalpha radiation ; R = 0.062 for 1332 reflections with F > 2 sigma(F). The molecule exh ibits a chair conformation. The atoms of the cis amide and the vinyl g roups are approximately coplanar. The charge distribution indicates th e increased reactivity of the terminal C(9) atom, which promotes the p olimerization reaction.