Several fluorinated aromatic amic acid and imide model compounds and their intermediates were prepared and investigated in N-methylpyrrolidinone by 19F and 13 C n.m.r. Starting materials included 4-fluoroaniline, 3-fluorophthalic anhydride, 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride and 2,2-bis(4- aminophenyl)hexafluoropropane. The advantages of 19F n.m.r, for studying amic acid and imide chemistry were numerous. Anhydride and amine starting materials, as well as amic acid, isoimide and imide compounds, were easily identified in the 19F n.m.r, spectra. Isomeric contents of amic acid mixtures were directly measurable. Many unique aspects of polyimide chemistry, such as amic acid equilibria and imide interchange reactions, could be quantitatively identified. Data from 13C n.m.r, and 19F n.m.r, were related in many cases, as were the carbon-fluorine coupling constants.
Посилання на статтю:
19F n.m.r, investigation of aromatic amic acid and imide model compounds. 1 / Carrington D. Smith*, Regis Mercier, Huges Waton and Bernard Sillion // Polymer. – 1993. – Vol 34. – P. 4852-4862.