Zirconium dodecaboride, from the ICSD CD-ROM

The B unit of zirconium dodecaboride has been reported as an icosahedron according to the Inorganic Crystal Structure Data Base, whereas the reference work actually confirmed a cubeoctahedral arrangement for B. Convergent beam electron diffraction was applied to verify the latter and original assignment

On the short C-C bond lengths in macrocyclic ligand systems incorporating ether donors: A comparative neutron and X-ray diffraction study of an O 2N3 donor macrocycle: 6,7,8,9,10,11,12,13,19,20-Decahydro- 5H-dibenzo[e,p][1,4,8,11,14]dioxatriazacycloheptadecine

The neutron diffraction structure of a 17-membered macrocyclic ligand incorporating an ON-donor set has been determined in order to investigate whether the C-C bond in the -OCHCH O- 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