Monoprotonated N,N,N'-trimethyl-1,8-diaminonaphthalene demonstrates fast exchange of H(in) and H(out) protons, in which a counterion (BF4(-) and Br(-) were tested) participates. The process can be frozen below 185 K revealing a tremendous magnetic separation (up to Δδ = 11.6 ppm) of these otherwise equal NH protons with the enzyme-like proton transfer and a ∼7 kcal mol(-1) energetic barrier.

This study demonstrates that fast proton exchange in N,N,N'-trimethyl-1,8-diaminonaphthalene can lead to tremendous magnetic separation of equal NH protons, with a 7 kcal mol(-1) energetic barrier.

Paper

Extreme magnetic separation of geminal protons in protonated N,N,N'-trimethyl-1,8-diaminonaphthalene. A puzzle of the fourth methyl group.

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