13C nuclear magnetic resonance study of the protonation sequence of some linear aliphatic polyamines

This is the authors' abstract. We don't add key points for this paper.

The 13C n.m.r. spectra are reported as a function of pH for 1,2-diaminoethane [en], N-(2-aminoethyl)propane-1,3-diamine [2,3-tri], 1,4,7,10-tetra-azadecane [trien], and 1,4,8,11-tetra-azaundecane [2,3,2-tet]. The previously reported amine shift parameters π and π+ are used to determine the protonation sites in the charged forms of the polyamines and the associated microscopic pKa values.