Cooperative interactions of unlike macromolecules:: NMR study of ionic of coupling of poly[2-(trimethylammonio)ethyl methacrylate chloride]-block-poly(N-(2-hydroxypropyl)methacrylamide) polycation with oligophosphates in D2O

Cooperative effects in the interactions of poly[2-(trimethylammonio)ethyl methacrylate chloride]-block-poly(N-(2-hydroxypropyl) methacrylamide) polycation with oligophosphates (phosphate glasses) leading to micellelike complexes were studied using NMR. H-1, C-13, N-14, Na-23, (31)p,and Br-79 single and double-quantum high-resolution and MAS NMR at 7.2 and 12 T of the complexes were studied at concentrations 0.1 and 0.02 mol/L of the ionic groups in D2O at 300-350' K. K-1, C-13, and P-31 longitudinal and transverse relaxations and Na-23, Cl-35, and(79)Br T-1(1), T-1(3) and T-2(3) time evolutions were studied to reveal the ionization states, local and semilocal mobilities, and ion coupling conversions in the products of the same polycation with polyphosphates of P-n = 15, 25, 35, 45, 65, and 75. Pulsed gradient spin-echo (PGSE) was used to measure self-diffusion coefficients and thus the size of both reactants and products. The results show that the ionic coupling is almost complete with polyphosphates of P-n up to 35 but decreases steeply with higher values of P-n. In all cases, the products are aggregates of ionic complexes, but their size:increases with higher P-n of the polyphosphate. The cooperativity in the products of self-assembling is discussed in terms of kinetic, thermodynamic (entropy), and microphase stabilization.