CRYSTAL-STRUCTURE AND CONFORMATION OF BIS-(TRICARBONYLIRON)HEPTALENE

Fe2C18O6H10 is monoclinic, space group P21/n with a = 12.517, b = 12.661, c = 10.632 Å, β = 90.92°, Z = 4. The structure was refined to R = 0.024 for 2702 counter reflections. The two outer butadiene moietes are exo complexed with tricarbonyliron units, thus forming tetragonal pyramidal iron complexes. The seven-membered rings of the heptalene have boat conformations with a flat central region and structure angles α = 6° and β = 41°. The molecules are packed in chains along the a-direction with shortest intermolecular distances between carbonyl units. © 1979.