Preparation and reactivity of a primary amino group attached to the centre of a polymethylene chain

Abstract

Polymethylenes with different chain lengths and having a central primary amino group were prepared. Rates of the reaction of the amines with 1,5-naphthalenedisulphonyl dichloride, a bifunctional fluorescent reagent, were measured by fluorometry in dilute solution. The rate constants obtained are equivalent to those for the reaction of two chain molecules having a functional group at each centre. Rates of the reactions of the amines with 5-dimethylamino-1-naphthalenesulphonyl chloride (a monofunctional fluorescent reagent), i.e. the reactions between a low molecular weight species and a functional group at the centre of a chain molecule, were also measured. Effects of chain length on reactivity of the central functional group, e.g. “local solvent medium effect” and “kinetic excluded volume effect,” are discussed briefly.