Crystal Structures and Side-arm Dynamics of Cerium meso-Tetrathienylporphyrin Double-decker Complexes

We prepared novel cerium meso-tetrathienylporphyrin double-decker complexes with 2-thienyl and 3-thienyl substituents. The X-ray structures show that the porphyrin rings are distorted in a half-pipe fashion, which seems to be a common type of distortion for double-decker complexes of tetraarylporphyrins. The side-arm thienyl groups rotate more than two orders of magnitude faster than the phenyl groups of the corresponding double-decker complex of meso-tetraphenylporphyrin in solution at room temperature because of the lower rotational barriers.