Structure of the two crystal phases of ferrocene carboxaldehyde
Abstract
The structure of the ordered low-temperature phase of ferrocene carboxaldehyde (C5H5FeC5H4CHO) has been determined from ambient-temperature single-crystal X-ray diffraction measurements. The structure is orthorhombic (space group P212121; Z= 4; a= 7.635 Å, b= 10.520 Å, c= 11.281 Å). The C5 rings are nearly eclipsed and the —CHO side group is almost coplanar with its ring.
This structure is used to develop a model for the local structural correlations in the previously studied high-temperature disordered phase (f.c.c., a= 9.99 Å). It is proposed that the average cubic symmetry arises from a superposition of 24 orientations of local structure essentially that of the low-temperature phase and a few unit cells in extent.