Kentgens, A.p.m.; De Boer, E.; Veeman, W.s.:
Ultraslow molecular motions in crystalline polyoxymethylene. A complete elucidation using two-dimensional solid state NMR.
1987
In: Journal of Chemical Physics (J.Chem.Phys.), Jg. 87 (1987), Heft 12, S. 6859 - 6866
Artikel/Aufsatz in Zeitschrift / Fach: Chemie
Titel:
Ultraslow molecular motions in crystalline polyoxymethylene. A complete elucidation using two-dimensional solid state NMR.
Autor(in):
Kentgens, A.p.m.; De Boer, E.; Veeman, W.s. im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen
Erscheinungsjahr
1987
Erschienen in:
Journal of Chemical Physics (J.Chem.Phys.), Jg. 87 (1987), Heft 12, S. 6859 - 6866
ISSN

Abstract:

The slow magic angle spinning 2D exchange NMR expt. applied to semicryst. polyoxymethylene shows the existence of ultraslow mol. rotations in cryst. regions of the material. Simulation of the 2-dimensional spinning sideband spectra, which are characteristic for the mol. motion involved, shows that a rotation of the polyoxymethylene helical chains over 200 Deg is responsible for the obsd. spectra. The activation energy is 20 kcal/mol, in good agreement with values obtained for the a relaxation in dynamic mech. and dielec. studies.