The diffraction patterns from sanidic polymers normally show 8-10 reflections of which only 4 or 5 are unique, so that it is impossible to solve their structure. A large number of equally probable models can easily be proposed. In this work, the monomeric analogs have been investigated by electron diffraction and imaging because they produce diffraction patterns which are rich in information and which can be analyzed to give the unit cell, its symmetry, and the direction of the molecule with respect to the cell axes. clear analogies can be drawn with the spacings observed in the polymeric materials above the glass transition temperature.