Conformational analysis was performed on some aromatic copolyesters in solution by means of ~H-~H nuclear Overhauser effect (NOE) measurements, using the cyclic dimer of isophthalic acid and ethylene glycol (DIMIS) as the model compound. From the observed NOE, a folding of the ethylene glycol towards the aromatic ring can be assumed for all the polyesters containing an isophthalic ring. In addition, the spatial interaction between adjacent aromatic rings, put forward in order to explain the chemical shift distribution observed in the 1H n.m.r, spectra of these copolymers, has been demonstrated with steady-state NOE experiments. The average distance between protons on adjacent aromatic rings has been calculated by means of dynamic NOE measurements. The most probable conformation, giving rise to these NOE effects, has been postulated on the basis of a formalism introduced in a previous work
Посилання на статтю:
Confornational analysis of some aromatic copolyesters in solution by means of 1 H_IH nuclear Overhauser effect experiments / Silvia Spera*, Riccardo Po" and Luigi Abis // Polymer. – 1993. – Vol 34. – P. 3380-3386.
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