Benzene ring deformations planarity

The deformation of the planar FePc molecule determines the free apertures to the active site. The latter can be derived from the distance between the benzene rings and the zeolite framework. The distance varies from 0.65 nm, for a deformation of 37.27°, to 0.52 nm, for a deformation of 67.27°. The distance between the centre of the molecule and the lattice oxygens is between 0.74 and 0.77 nm. 

The orthorhombic structure of solid benzene is shown in fig. 14.22. The molecules are again planar hexagonal rings of closely the same dimensions as in hexamethylbenzene but their mutual arrangement is quite different. Each molecule has its plane very nearly parallel to the z axis of the cell, but the molecules are inclined about this axis in two directions nearly at right angles. The centres of the molecules lie at the corners and at the centres of the faces of the cell, so the structure is a relatively compact arrangement which may be looked upon as a cubic close-packed array deformed to accommodate the aspherical molecules. The closest distance of approach between adjacent molecules is about... 

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