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Organometallics 1990, 9, 1290-1295
Reactions of Bis(cyclopentadieny1)dimethylzirconium with Fluorocarbon Acids. Structure, Dynamic Properties, and "Zr NMR Spectra of (C5H5),Zr[ HC( S02CF3),- 0 ,0 ' ] [HC( S02CF3),- 0 ] A. R. Siedle,' R. A. Newmark, W. B. Gleason, and W. M. Lamanna 3M Corporate Research Laboratories, St. Paul, Minnesota 55 144 Received August 1, 1989
Reaction of Cp2Zr(CH3), with 1 and 2 equiv of fluorocarbon acids such as H2C(S02CF3),yields Cp2Zr(CH3)[HC(SOZCF3),] and C Zr[HC(S02CF3)I,, respectively. The structure of the latter compound (crystal data: P1, a = 8.834 (2) -8)'b = 15.480 (5) c = 20.887 (6) A, a = 109.71 ( 2 ) O , (3 = 90.64 ( 2 ) O , y = 95.20 (2)' at -100 "C, 2 = 4, R = 0.033, R, = 0.045) demonstrates two HC(S02CF3),ligands. One is bidentate and the other one monodentate, both being bonded to Zr through the sulfone oxygen atoms. The two types of ligands interconvert rapidly on the NMR time scale. 91Zrchemical shifts are reported.
A,
Introduction We have previously pointed out the advantages of use of the fluorocarbon acids H,C(SO,CF,), (11, PhCH(S02CF3),(21, and HN(SO,CF,), (3) for synthesis of cationic organometallic compounds. These include solubility in noncoordinating, apolar solvents and the nonhygroscopic nature of 1 and 2.' With few exceptions, HC(SO,CF,),and its congeners do not coordinate to complex cations formed from middle- and late-transition-metal elements. In (Ph3P),Pt(H)[HC(S0,CF3)2-C], the fluorocarbon acid moiety is covalently bonded to platinum through the methine carbon and in Ti,(~-i-PrO),(i-PrO),[HC(SOzCF3)2-0,0'j2, the HC(S02CF3),ligand is bonded to titanium through the sulfone oxygen atoms.4 Reactions of 1 with bis(cyclopentadieny1) alkyl derivatives of the electropositive element zirconium have been studied in the expectation of obtaining actual or incipient cationic complexes. Such materials, e.g. [Cp2Zr(CH3)(THF)] [BPh,], have attracted attention as ethylene polymerization catal y s t ~ as , ~ have alkylchromium cations6 X-ray photoelectron spectroscopy data indicate that Cp2Zr(CH3)+is the active species in the Cp2Zr(CH3)2-(CH3A10),olefin polymerization catalyst system.: Surface-supported cationic thorium complexes are also active as olefin POlymerization catalysts.s Protonation of Cp*,Zr(CH,), (Cp* = (CH3),C5) with CF3S03H to form Cp*2Zr(CF3S03)2, which can be methylated by (CH&,Al to produce (1) (a) Siedle, A. R.; Newmark, R. A,; Pignolet, L. H.; Howells, R. D. J . Am. Chem. SOC.1984, 106, 1510. (b) Siedle, A. R.; Newmark, R. A.; Pignolet, L. H. Organometallics 1984, 3, 655. (c) Siedle, A. R.; Newmark, R. A.; Pignolet, L. H.; Wang, D. X.; Albright, T. A. Organometallics 1986, 5 , 38. (d) Siedle, A. R.; Newmark, R. A,; Pignolet, L. H. Inorg. Chem. 1986,25, 1345. ( e ) Siedle, A. R.; Newmark, R. A.; Pignolet, L. H. Inorg. Chem. 1986,25,3412. (f) Siedle, A. R.; Newmark, R. A.; Howells, R. D. Inorg. Chem. 1988, 27, 2473. (g) Siedle, A. R.; Newmark, R. A,; Korba, G. A,; Pignolet, L. H.; Boyle, P. D. Inorg. Chem. 1988, 27, 1593. (h) Siedle, A. R. In Aduances in Boron and the Boranes; Liebman, J. F., Greenberg, A,, Williams, R. E., Eds.; VCH: New York, 1968; p 373. (2) Siedle, A. R.; Newmark, R. A. J . Am. Chem. Soc. 1986, 108, 767. (3) Siedle, A. R.; Gleason, W. B.; Newmark, R. A.; Pignolet. L. H. Organometallics 1986, 5, 1969. (4) Siedle, A. R.; Huffman, J. C. Inorg. Chem., in press. (5) (a)
