THE DYNAMICS OF WATER-MOLECULES IN HYDRAT ED SOLID POLYGLYCINE - ANALYSIS OF THE FORM OF H-1-NMR FREE INDUCTION SIGNALS AND SPIN-LATTICE RELAXATION

Proton relaxation in a system polyglycine-water has been studied to ob tain information on the dynamics of water and polyglycine molecules. M easurements for dry and humid (h=13%) specimens were made at 10,8 and 27 MHz resonance frequencies in a temperature range between 105 and 30 0 K. The values of T-1 and free induction signals were measured. Prima ry emphasis was placed on component-by-component analysis of free indu ction signals throughout the temperature range. As a result, the tempe rature dependences of the second moments (T-2 times) separately for wa ter and polyglycine molecules were obtained. From the analysis of temp erature dependences of relaxation times T-1 ant T-2, the parameters of movement of hydration water molecules (E(a) = (28+/-1) kJ/mole, tau(0 ) = 10(-10) s (293 K)), the parameter of distribution of correlation t imes (sigma=0,52), and dynamics temperature of vitrification at 20 kHz (T-g approximate to 145 K) were estimated using a model-free approach . In humid polyglycine sample, a high-amplitude movement of atoms of t he main chain was revealed at temperatures above 165 K. The correlatio n times of the movement are in a microsecond range and the amplitudes of CH2-group oscillation are about 30 degrees (beta-relaxation transit ion).