Dynamics and molecular aggregation in crystalline [{M(C5H5)}3(µ3-η2 : η2 : η2-C6H5R)][M = Co, R = CH(Ph)Me, CH2CH2Ph or CHCHMe; M = Rh, R = H] clusters

Abstract

The intermolecular aggregation in crystalline arene clusters of the type [{M(C₅H₅)}₃(µ₃-η² : η² : η²-C₆H₅R)][M = Co, R = CH(Ph)Me, CH₂CH₂Ph or CHCHMe; M = Rh, R = H] has been investigated by atom–atom packing potential-energy calculations and computer graphics. The ease of reorientation of the arene fragments and of the cyclopentadienyl ligands in the solid state has been investigated by calculating intramolecular and intermolecular potential-energy barriers. It has been shown that, except for the benzene ligand in [{Rh(C₅H₅)}₃(µ₃-η² : η² : η²-C₆H₆)], the facial arenes cannot undergo reorientation in the solid state, whereas the reorientational motion of the cyclopentadienyl ligands is under intramolecular control.