The Crystal Structure And Costitution Of Some Molecular Complexes Of 4:41 -Dinitrodiphenxl

Abstract

The crystal structures or a number of molecular

complexes formed by 4a4'•din1trodiphenyl with various diphenyl

derivatives are described. The general type of structure is

undoubtedly the same tor all the complexes examined and the

typical arrangement may be taken as that in the complex of

4·z4 1 .. dinitrodiphenyl with 4-hydroxydiphenyl, the structure of

which has been tully determined. As shown 1n fig. 7 the

dinitrodiphenyl molecules form layers in face•centred array

and lie one above the other with a spacing or about 3•7 A.

The arrangement of these molecules alone is such that a set

of tubular cavitiesf also in face-centred array, run through

the structure. In the complexes these cavities are occupied by

the other component molecules, the hydroxydiphenyl molecules in

the case considered; which thus lie nearly normal to the planes

containing the dinitrodiphenyl molecules and are seen end-on

in fig. 7. In the other structures examined geometrical and

symmetry conditions require that the individual molecules

should be tilted in varying degrees, but the type or structure

still remains essentially the same.

It is shown that the ratio of the components in these

complexes is determined by the length of the molecule other than

dinitrodiphenyl, and that 1n no case is it necessary for the

intermolecular distances to be shorter than those found in

crystals or ordinary aromatic nitro-compounds...