Isolation and Characterization of Bromination Products of Zr(C5H5)2Br2

The reaction of Zr(C5H5)2Br2 with bromine can be used as an effective route to Zr(C5H5)Br3. Through the slow addition of reactants, Zr(C5H5)Br3 can be isolated in crystalline form. An X-ray diffraction study has revealed it to exist as a one-dimensional polymer, isomorphous with Zr(C5H5)Cl3. In the presence of excess bromine, additional loss of C5H5 occurs, leading to the formation of the salt complex [Zr3(C5H5)3Br3(μ2-Br)3(μ3-Br)2]+[Zr2Br9]−, as well as additional products. However, use of Zr(C5H5)2Br2 that has been exposed to air leads to traces of a water complex, Zr2(C5H5)2Br4(μ2-Br)2(μ2-H2O), which has been revealed through a structural study as having a confacial bioctahedral geometry, with the water serving as one of the three bridging ligands.