Szafran, M. published the artcileDifferences in proton-proton coupling constants of N+-CH2-CH2 protons of some betaines, N+-(CH2)2-3-COO–, and their complexes in aqueous solution, Safety of 3-Carboxy-N,N,N-trimethylpropan-1-aminium chloride, the publication is Journal of Molecular Structure (2001), 555-564, database is CAplus.
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 pos. 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 is consistent with preference for trans conformation (68-85%). In the spectra of compounds with two CH2 groups in the tether or three CH2 groups and unsubstituted pyridine ring, the multiplet changes to a triplet and gives apparent A2X2 and A2M2X2 spectra, resp., consistent with no significant conformational preference. Both the number of CH2 groups in tether and the bulkiness of the charged groups are responsible for the observed differences of N+CH2 multiplicity and reflect changes in conformational preferences. According to the PM3 calculations, in the gas phase a gauche-like conformer is more stable than the trans, but in aqueous solution it is reverse.
Journal of Molecular Structure published new progress about 6249-56-5. 6249-56-5 belongs to chlorides-buliding-blocks, auxiliary class Phase Transfer Catalyst,Inhibitor,Natural product, name is 3-Carboxy-N,N,N-trimethylpropan-1-aminium chloride, and the molecular formula is C24H12, Safety of 3-Carboxy-N,N,N-trimethylpropan-1-aminium chloride.
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