Preparation of multiply positively charged substances usable for stable modification of negatively charged solid materials

J. Jindřich, P. Kasal
Charles University,
Czech Republic

Keywords: electrostatic binding, negatively charged solid, positively charged modifier

Summary:

The subjects of our invention [CZ PV 2019-731] are (a) preparations of a new type of multiply positively charged substances - anchors to which almost any chemical substance can be easily covalently bound using "click" reactions, (b) preparation of modifiers of negatively charged solids using the click reaction with the anchors, (c) use of such modifiers for stable functionalization of the charged solids by the electrostatic (ionic) binding. The positively charged anchors contain 1 to 24 positive charges - quaternary ammonium groups - concentrated to a small space using a neopentyl skeleton (functioning also as a stabilizer preventing Hofmann elimination) and optionally by cyclodextrin skeleton (functioning as a multiplier). The anchors can be prepared from common chemicals without a need for chromatographic separations. The negatively charged material (cation exchange resin, zeolite, Nafion, silica gel, aluminum oxide, glass surface) can be modified by merely immersing it in an aqueous solution of the modifier. In this way, many materials used in practice can be prepared more readily, as demonstrated by the preparation of a modified silica gel solid-phase suitable for chromatographic separation, usable in a wide range of pH values.