Layered [3.3]Orthocyclophane Tricarbonylchromium Complexes

The preparation of the layered [3.3]orthocyclophane tricarbonylchromium mono- and bis complexes, 4 and 5 , are described. X-ray crystallographic analysis reveals the fact that the distances and the dihedral angle between the planes of the two benzo rings in mono complex 4 decrease as compared to those in 1 . This is due to the decrease in π electron density in one benzo unit.