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A structural investigation of octa-n-undecoxyphthalocyanine in the solid and liquid-crystalline state and of poly(octa-n-undecoxyphthalocyaninato)siloxane by high-resolution solid-state NMR spectroscopy

Journal Article · · Journal of the American Chemical Society; (United States)
DOI:https://doi.org/10.1021/ja00180a022· OSTI ID:5170931
;  [1]; ;  [2]
  1. Univ. of Nijmegen, Toernooiveld (Netherlands)
  2. Univ. of Utrecht, Padualaan (Netherlands)
{sup 13}C high-resolution NMR spectra of octa-n-undecoxyphthalocyanine (Pc) were measured in the solid and in the liquid-crystalline state. In the solid state, crystallographic splittings are observed which can be attributed to distortions of the molecular symmetry of the Pc core. These distortions are probably connected with the tilting angle between the planes of the Pc molecules and the axis of the columns formed by these molecules. Temperature-dependent measurements show that the N-H tautomerism in the Pc core displays no obvious asymmetries. Above 380 K the solid phase of the Pc molecules is transformed into a hexagonal-ordered columnar mesophase. In this mesophase the molecular Pc plane is perpendicular to the stacking axis, with the molecules rotating about the stacking axis. There is no clear deviation from the molecular D{sub 4h} symmetry in the mesophase. The side chains display a liquid-like conformation in the mesophase.
OSTI ID:
5170931
Journal Information:
Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 112:24; ISSN 0002-7863; ISSN JACSA
Country of Publication:
United States
Language:
English