PORPHYRIN SPONGES - INVERSION DISORDER AND INVERSION TWINNING IN LATTICE CLATHRATES BASED ON 5-COORDINATE METALLOTETRAARYLPORPHYRIN COMPLEXES

X-ray structural characterization has played a key role in revealing the potential of metalloporphyrin complexes as lattice clathrates, and further structural work is essential to the development of many applications of these ''porphyrin sponges''. Clathrates based on five-coordinate tetraphenylporphyrin (TPP) complexes, however, often exhibit an incomplete inversion disorder that precludes accurate structure determination by standard methods. This report describes a refinement procedure that models the inversion disorder and twinning and allows the extraction of accurate structural information. Multiple-temperature structural data are provided for Fe(III)TPP(benzenethiolate) as the toluene and chlorobenzene solvates, as well as for Fe(III)TPP(p-bromobenzenethiolate) as the toluene solvate. Structural data are also provided for an unsolvated and completely ordered form of Fe(III)TPP(benzenethiolate). Observation of some highly disordered but untwinned specimens of the solvates suggests that the residual order is created at the crystal/solution interface during crystal growth. Structural variations among the ten determinations carried out are consistent with admixed S = 3/2:S = 5/2 ground states for these materials.