PUB - Publikationen an der Universität Bielefeld

Reaction of 1,1',3,3'-tetra-tert-butyl-5-5'-pentafulvalenedipotassium (1) with hexacarbonylmolybdenum leads to hexacarbonyl-dipotassium(1,1',3,3'-tetra-tert-butyl-5,5'-pemtafulvalene)dimolybdate (2), which on further treatment with stoichiometric amounts of iodomethane yields the hexacarbonyldimethyl(1,1'-3,3'-tetra-tert-butyl-5,5'-pentafulvalene)dimolybdenum, ([eta]5 : [eta]5-tBu4C10H4)Mo2(CO)6-(CH)3)2 (3). Compound 3 is obtained as yellow needles and brownish cube-like crystals, and it is characterized by 1H-NMR, 13C-NMR, IR, and MS data. The cubes crystallize in the space group C2/c with four molecules in the unit cell. Each molecule consists of two tricarbonylmethyl(cyclopentadienyl) molybdenum units which are connected by a central C-C-bond, twisted against each other by 64.8° and bent by 25.8°. Due to the steric requirements of the tert-butyl substituents in the fulvalene ligand, 3 should be formed only from cis-configurated 2.