THE STRUCTURE OF PROTONATED DIAMINES AND POLYAMINES

The reduced mobilities in air, at 200-degrees-C, of six isomeric C7H18 N2 protonated diamines, two triamines (caldine and spermidine), and tw o tetramines (thermine and spermine) were measured by ion mobility spe ctrometric (IMS) techniques. The results indicated that all these poly amines undergo proton-induced cyclization, with the proton forming a b ridge between two amino groups. It appears as if the favored configura tion of the protonated polyamines involves a six- or seven-membered ri ng rather than a bridge between the terminal amino groups. It is belie ved that in the tetramines the cyclic structure is formed between the two central, more basic, secondary amine sites.