Synthesis, spectroscopic and structural characterization of the first mixed fluoro-bromo group 4 organometallic complex [{Cp*ZrF2Br}4] (Cp* = C5Me5)
摘要:
Abstract[{Cp*ZrF2Br}4] is conveniently prepared in high yield from the reaction of [{Cp*ZrF3}4] with four equivalents of Me3SiBr. In contrast the reaction of [{Cp*ZrF3}4] with Me3SiI under identical reaction conditions leads to a mixture of [Cp*ZrI3] and unreacted [{Cp*ZrF3}4]. The crystal structure of [{Cp*ZrF2Br}4] has been determined by X‐ray diffraction studies. The compound crystallizes in the orthorhombic crystal system [a = 9.325(1), b = 23.483(3), c = 27.016(5) Å, α = β = γ = 90°, space group Ibam, Z = 4]. The tetrameric core structure of [{Cp*ZrF2Br}4] contains four zirconium atoms linked by alternating single and triple fluorine bridges. One terminal bromine atom is bonded to each zirconium. 1H and 19FNMR spectroscopic data and structural features of the title compound are compared with those for the mixed fluoro‐chloro complexes [{Cp*ZrF2Cl}4], [{Cp*ZrF2Cl}2{Cp*ZrFCl2}2] and the trifluoro complex [{Cp*ZrF3}4].