NMR RELAXATION STUDY OF THE REACTION OF 3-HYDROXYPYRIDINE WITH MACROMOLECULES IN SOLUTIONS

The concentration dependences of the rates of C-13 nuclei spin-lattice relaxation in molecules of 3-hydroxypyridine (HP), pyridine (P), and phenol (Ph) in aqueous solutions of polyethylenimine (PEI) and polyacrylic acid (PAA) were obtained. The average complexing constants of HP with these polymers were calculated with the experimental data and the anisotropy of rotation of molecules of HP, P, and Ph in aqueous solutions and in complexes with PAA and PEI were determined. A comparative analysis of the change in the anisotropy of rotation of the molecules and efficiency of formation of hydrogen bonds by different groups was conducted. The expediency of using HP as a probe for studying the complexing capacity of different molecular groups in the chains of polymers was demonstrated.