Electronic absorption spectra of aliphatic diamine radical cations. Conformation‐dependent charge delocalization

Electronic absorption spectra of radical cations generated by steady‐state and pulse radiolysis from a series of α,ω‐diaminoalkanes (R 2 N(CH 2 ) n NR 2 ; n = 1–6, R = CH 3 or C 2 H 5 ), 1,4‐dimethylpiperazine and 1,4‐diazabicyclo [2.2.2] octane (DABCO) were measured. In some cases spectral evidence was obtained for an interaction between the nitrogen atoms leading to charge delocalization in the radical cation. A delayed formation of radical cations was associated with a conformational change necessary for achieving the most stable structure having a favourable conformation for charge delocalization.