ISOLATION AND COMPLETE NMR AND X-RAY CRYSTALLOGRAPHIC CHARACTERIZATION OF AN UNUSUAL PENTADIENYLLUTETIUM COMPLEX, U(ETA(5)ETA(5)-MEC(5)H(5)CH(2)CH(2)CHMEC(3)H(3)ME)

From the metathesis reaction of (2,4-dimethylpentadienyl)potassium wit h lutetium trichloride (3:1 reaction stoichiometry) has been isolated a novel pentadienyllutetium complex, (eta )Lu(eta(5):eta(3)-(CH3)C5H5C H2CH2CH(CH3)C3H3(CH3)) (1), which contains a dimeric chelate ligand de rived from the end-to-end fusion of two 2,4-dimethylpentadienyl groups . The solid-state structure of 1 was established through single-crysta l X-ray diffraction analysis. Resonances in the H-1 and C-13 NMR spect ra were completely and unequivocally assigned by 2D NMR techniques and show the complex to be in an asymmetric conformation in solution.