Claude Quivoron

The Errors in the Treatment of Gel Permeation Chromatography Data: Origins and Corrections

Abstract This paper deals with the origins of errors in data interpretation when using modern GPC with dual detection (refractometer-viscometer) as a method of determination of average molecular weights of polymers. We describe here the different errors classified in two groups: typical chromatographic errors and data treatment errors and we show that they can lead to very miscalculated molecular weight values. For every case, we have tried to propose the best way to avoid or correct these errors so as to use modern GPC as a very accurate method of polymer characterization.

13C and 23Na n.m.r. studies of the interactions between cations and kryptofix (2,2) bound to soluble or gel polyacrylamide

Abstract Interactions between univalent cations (Li + , Na + , K + , Ag + ) and bivalent cations (Ba 2+ , Ca 2+ ) with kryptofix (2,2) substituted polyacrylamide have been investigated using 13 C n.m.r. The tendency to form complexes involves the dimensions of both the hydrated ion and the cavity size macrocycle and for Ag + the nature of the interaction site. The sensitivity of the 23 Na n.m.r. method for detecting complex formation in solution from macromolecular species has been applied to the determination of the conditional formation constants of Na + and Ba 2+ complexes.

Chromatographic Study of Interactions Between N,N-Disubstituted Polyacrylamides and Phenols Comparison with Infrared Spectroscopic Data

Abstract The determination of retention data by liquid chromatography (LC), for a series of p-substituted phenols on various packings formed with N,N-disubstituted polyacrylamides, permits characterization of polymer-solute interactions which govern the partition of phenols between the mobile and the stationary phases. The partition coefficient, Kj, changes with the nature of the polymer, and increases with the phenolic acidity. We propose a linear relationship between Kj and the complexation constant of phenol-amide hydrogen bond, determined by infrared spectroscopy. This relationship has been qualitatively checked.

Koenigs Knorr Reaction Catalyzed by Supported Crown Ethers: An Example of the Polymer Influence

The complexing ability of crown ethers has been extensively investigated and their remarkable complexation behavior has found various applications in analytical and synthetic chemistry1. For instance, many chemical reactions can be influenced by the use of these compounds. By complexing the cation of a metal salt, an enhancement of the reactivity of the anion may result.