Molecular Structure of the Complex of Octano-8-lactam with Magnesium Bromide

Abstract

Octano-8-lactam forms a complex with magnesium bromide, which could be of importance in elucidating the mechanism of anionic polymerization of the lactam initiated by Grignard compounds. The complex was obtained in pure form and analyzed using thermal analysis (DSC and TGA), multinuclear NMR and IR spectroscopy. Analysis of 1H, 13C, 14N and 15N NMR spectra, relaxations and PGSE measurements, as well as IR spectra and well-corresponding theoretical calculations, showed that six molecules of octano-8-lactam and one MgBr2 molecule form a complex with high symmetry. Two different forms of the complex were found, one of them strongly predominating.