REACTION OF (1,8-NAPHTHALENDIYL)MAGNESIUM WITH GROUP-5 AND GROUP-6 METALLOCENE DICHLORIDES - FORMATION AND X-RAY CRYSTAL-STRUCTURE OF (TAU-5-CP)MO(PME3)2- 3-6B-H-7,9A-DIHYDROCYCLOPENT[A]ACENAPHTHYLEN-7-YL)

The reaction between (1,8-naphthalenediyl)magnesium (1) and Cp2MCl2 (M = V, Nb) gave perylene (3) in quantitative yield. However, reaction b etween 1 and Cp2MoCl2 in the presence of PMe3 yielded the remarkable c omplex PMea)2(eta3-6b-H-7,9alpha-cyclopent[alpha]acenapht hylen-7-yl) (4). Its X-ray crystal structure revealed that one of the original cyc lopentadienyl rings is eta3 bonded to the metal center and twice sigma -bonded to C(1) and C(8) of the naphthalene moiety. Complex 4 crystall izes in the orthorhombic space group Pnma with a = 15 274(11) angstrom , b = 14.953(3) angstrom, c = 10.3620(14) angstrom, v = 2366.6(18) ang strom3, and Z = 4. Convergence was reached at R = 0.064 and R(w) = 0.0 69 for 144 parameters and 1814 diffraction data (I > 2.5sigma(I)).