| Autor: |
Madeleine Rey-Lafon, Francis Cruege, B. Sebille, Jean Lascombe, Claude Quivoron, P. Combelas |
| Rok vydání: |
1970 |
| Předmět: |
|
| Zdroj: |
Spectrochimica Acta Part A: Molecular Spectroscopy. 26:1323-1335 |
| ISSN: |
0584-8539 |
| DOI: |
10.1016/0584-8539(70)80038-1 |
| Popis: |
The carbonyl stretching frequencies ν(CO) of an N,N-disubstituted polyacrylamide and some simple amides which are representative of its repeat unit have been observed in the infrared spectra of solutions of these molecules in a number of inert and active solvents. A comparison of the results shows that the carbonyl group of the polymer is relatively insensitive to solvent effects. Furthermore, a study has been made of the spectra in the carbonyl stretching region, 1500–1700 cm −1 , of these compounds in mixtures of an inert solvent and a proton donor in various proportions. The results indicate that depending on the proton donor chosen, simple amides form complexes of the types (A) (B) and (C) but that with the polymer only complex (A) results. Finally, the equilibrium constants for complexation of an amide group of the macromolecule or the simple amides with iodine or a phenolic molecule have been determined by infrared spectroscopy. The constants are in general half as large for the amide group of the polymer as for the simple amides. The differences in the acid-base properties have been interpreted on the basis of two factors which appear to be correlated: (1) the existence of strong interactions of the dipole-dipole type between the amide groups of the same macromolecule and (2) steric hindrance by the various conformations of the macromolecule to the approach of complexing solvent molecules. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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