This article recapitulates the state of the art regarding simulations of ionization equilibria of weak polyelectrolyte solutions and gels.

In this work we study the titration behavior of weak polyelectrolytes by computer simulations.

More than 160 new hyperfine components of rotational transitions of the free fluoroformyloxyl radical $\mathrm{F}\mathrm{C}{\mathrm{O}}_2\cdot$ have been measured using the Prague millimeter wave high resolution spectrometer. The frequencies of these transitions together with the previously measured data were analyzed in detail and precise values of magnetic hyperfine and fine parameters were obtained. These new parameters significantly improve the values of previously determined hyperfine parameters which were rather unreliable. The new fine and hyperfine parameters obtained in this study are compatible with those of the simultaneously electron paramagnetic resonance study. Besides that, significantly improved ground state rotational and centrifugal distortion constants of the fluoroformyloxyl radical were derived.

The rotational spectra of the fluorosulfate $\left({\text{FSO}}_3\cdot \right)$ molecular radical in its vibronic ground state were measured in the millimeter-wave region and analyzed in detail using the matrix elements of the rotational, fine, and hyperfine Hamiltonian terms. The analysis of the assigned transition frequencies made it possible to derive very precise values of the rotational, centrifugal distortion and fine structure constants and to confirm the $C_{3v}$ molecular symmetry of the vibronic ground state unambiguously. In addition, an effective parameter of the “$A_1\text{-}{A}_2$ splitting” was determined. The rotational transitions of the ${\text{FSO}}_3\cdot$ free radical were observed, identified, and analyzed for the first time.