SUBSTITUTED CYCLOPENTADIENYL PHOSPHINOMETHYL COMPLEXES OF ZIRCONIUM - SYNTHESIS, CHEMICAL CHARACTERISTICS, COMPLEXATION WITH RHODIUM COMPLEXES, AND CATALYTIC PROPERTIES - MOLECULAR AND CRYSTAL-STRUCTURE OF (ETA-5-TERT-BUC5H4)2ZR(CH2PPH2)2[RH2(MU-S-TERT-BU)2(CO)2]

The synthesis of Cp’2Zr(CH2PPh2)2 (1) and Cp2ZrCI(CH2PPh2) (2) (Cp = r¡ -f-BuC5H4) is reported. The H NMR spectrum of 2 shows four separate ring proton absorptions, unambiguously assigned by decoupling experiments and simulated spectra. Reduction of 2 with Na/Hg produces a paramagnetic Zr(III) species formulated as Cp’2Zr(CH2PPh2) (3). Reduction of 1 with sodium naphthalenide leads to the monocyclopentadienyl Cp'Zr(CH2PPh2)2 species 6 characterized by EPR features and simulated spectra. Evolution of 6 gives the hydridozirconium(III) species 7 able to hydrogenate, in a catalytic way, various olefins. Reactions of 1 with the cationic rhodium complex Rh(COD)(PPh3)2BPh4 and the neutral dinuclear complex Rh2^-S-f-Bu)2(CO)4 produces the bimetallic complexes Cp'2Zr(CH2PPh2)2[Rh(COD)]BPh4 (8) and Cp'2Zr(CH2PPh2)2[Rh2(M-S-r-Bu)2(CO)2] (9), respectively. The X-ray structure of 9 was determined, giving the followlngj;rystal data: space group P2,/n, a-14.320 (2) A, b = 19.488 (3) Λ, c = 19.405 (2) Â, β = 95.08 (2)°, V = 5394 Λ3, Z = 4. The crystal structure displays relatively normal Zr and Rh geometric environments. Results for the catalytic hydroformylatlon of 1-hexene with 9 can be related to the f-Bu electronic effect. © 1990, American Chemical Society. All rights reserved.