AMIDO-THIOETHER POLYMERS CONTAINING PENDANT CARBOXYLATO GROUPS - THERMODYNAMICS OF PROTONATION AND COPPER(II) COMPLEX-FORMATION IN DILUTE AQUEOUS-SOLUTION

Calorimetric data are reported for the enthalpy of protonation of pend ant carboxylato groups in new polymers 1a - d containing amido and thi oether moieties in their main chain. These data, together with potenti ometric and viscometric data, afford a complete thermodynamic descript ion of the protonation process of the new polyacids, which are water-s oluble in a narrow range of alpha (degree of protonation) values. Comp arison with the non-macromolecular model 2 revealed that the thermodyn amic features are attributable to polyelectrolyte effects. In contrast with model 2, all polymers studied form stable hydroxocomplex species with copper(II) ion. The hypothesized [Cu(OH)2L2]2- (where L is the m onomeric unit of the polymer) stoichiometry fits the potentiometric da ta well when processed with the SUPERFIT program. The trend of the cor responding stability constant (log beta) values is to decrease with in creasing pH over a wide range.