FIRST MIXED FLUORO-CHLORO GROUP-4 ORGANOMETALLICS - SYNTHESIS AND SPECTROSCOPIC AND STRUCTURAL CHARACTERIZATION OF [((C(5)ME(5))ZRF2CL)(4)], [((C(5)ME(5))HFF2CL)(4)], C(5)ME(5))(4)ZR-4(MU-F)(MU-F-2)(2)(MU-CL)(2)CL-4], )ME(5))(4)HF-4(MU-F)(2)(MU-F-2)(2)(MU-CL)(2)CL-4], [(C(5)ME(4)ET)(2)ZRCLF], AND [(C(5)ME(5))(2)HFCLF]

Tetrameric [{(C(5)Me(5))MF(3)}(4)] (M = Zr, Hf) react smoothly with Me (3)SiCl in CH2Cl2 at room temperature to give [{(C(5)Me(5))ZrF2Cl}(4)] (1) and [{(C(5)Me(5))HfF2Cl}(4)] (2), respectively, in high yield. Tr eatment of [{(C(5)Me(5))MF(3)}(4)] (M = Zr, Hf) with Me(2)AlCl in tolu ene gives mixtures of 1 and 5)Me(5))(4)Zr-4(mu-F)(2)(mu-F-2)(2)(mu-Cl) (2)Cl-4] (3), and 2 and (5)Me(5))(4)Hf-4(mu-F)(2)(mu-F-2)(2)(mu-Cl)(2) C-4] (4), respectively, in an approximately 1:1 molar ratio. Metalloce ne type complexes [(C(5)Me(4)Et)(2)ZrCl2] and [(C(5)Me(5))(2)HfCl2] re act with 1 equiv of Me(3)SnF to give [(C(5)Me(4)Et)(2)ZrCIF] (5) and [ (C(5)Me(5))(2)HfCIF] (6), respectively. The complexes 1-6 were charact erized by spectroscopic methods (H-1 and F-19 NMR and mass spectroscop y). The solid state structures of 1, 3, and 5 were determined by singl e-crystal X-ray diffraction analyses.