Answers are grounded in this paper and cite their sources.
NMR studies reveal that the equilibrium between 1 and 2 lies essentially toward 1 to the left without any detectable amount of 2. DFT computation shows that the value of K1 is about 1.4 x 10-5, and X-ray crystal structures show that the resonance-assisted hydrogen bond (RAHB) in 1 (1.66 A) is shorter than the regular hydrogen bond in 2 (1.75 A). The enormous selectivity can be explained in terms of the strength of the RAHBs in 1 compared to that of the regular hydrogen bonds in 2.
No takes yet. Share an insight, caveat, or question.
Chin et al. (2003) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: