Combined X-ray Diffraction and ~15N CPMAS NMR Study of Molecular Structure and Proton Order/Disorder Phenomena in Cyclic N,N'-Bisarylformamidine Dimers

摘要

XRD then observes disordered hydrogen-bond protons and, in principle, also disordered nitrogen atoms. However, in practice, the disorder of the latter is not resolved leading to the observation of equalized C...N bond lengths. Finally, dimmers (I,IV) represent an intermediate case with K_ab<1, which could be labeled as "dynamic partial order". The implications of the molecular structure and the hydrogen bond and proton transfer characteristics are discussed.