Synthesis and 1H NMR spectra in D2O of 4 betaines and 19 betaine complexes with mineral acids containing 2 or 3 CH2 groups in the tether, N+–(CH2) n–COO−, n= 2, 3, and diverse volume of the positively charged groups are reported. In compounds containing three CH2 groups in the tether and three substituents at the nitrogen atom or α, α′-disubstituted pyridine ring, a characteristic multiplet for an AA′ MM′ X2 spin system is observed. This ...
