Investigation of an N···H hydrogen bond in a solid benzoxazine dimer by 1H–15N NMR correlation techniques under fast magic‐angle spinning

The N···H distance within the unusual hydrogen‐bonding arrangement adopted by a pair of methyl‐substituted benzoxazine dimers (C6H3(OH)2CH2)2N(CH3) has been determined by solid‐state NMR to be 194 ± 5 pm. This indicates that the proton is shared between the nitrogen and oxygen atoms, with a preference for an O H rather than an N H bond character. It is to be noted that a previous X‐ray single crystal study was unable to localize the position …