On the short C–C bond lengths in macrocyclic ligand systems incorporating ether donors: a comparative neutron and X-ray diffraction study of an O2N3 donor macrocycle: 6,7,8,9,10,11,12,13,19,20-decahydro-5H-dibenzo[e,p][1,4,8,11,14]dioxatriazacycloheptadecine

Abstract

The neutron diffraction structure of a 17-membered macrocyclic ligand incorporating an O₂N₃-donor set has been determined in order to investigate whether the C–C bond in the –OCH₂CH₂O– atom string remains short as found in the corresponding X-ray structure of this compound; the evidence suggests that the short bond found by X-ray diffraction in this as well as in many other polyether compounds is largely an artefact with the ‘real’ component of the shortening being quite minor.