Organometallics CHEM 534 Midterm TAKE HOME exam Oct. 18, 2004 Answers to the portion of the exam given by Prof. Malachowski13. Schwartz's reagent, Cp2ZrH(Cl), has found considerable use in synthetic chemistry, primarily due to several unique anduseful properties of the zirconium reagent and organometallic complexes that it forms.b) One characteristic of alkyl-zirconium complexes, such as the product in part a, is their unusual stability. Why do you thinkalkyl-zirconium complexes are more stable than other alkyl-metal complexes?CpZrCpCla) One of the useful reactions of Schwartz's reagent is 1,2-insertion across alkenes. Show the 1,2-insertion product ofSchwartz's reagent with 1-pentene.Cp2ZrH(Cl) + 1-penteneSince alkyl-zirconium complexes, such as shown in part a, are with Zr(IV), they have no d orbital electrons. Without any dorbital electrons, the metal can not add electron density to the C-H * orbital, which is the first step in -elimination or1,2-deinsertion reactions.c) The alkyl-zirconium complexes can undergo a range of oxidation reactions, e.g. reaction with I2.Many alkyl-metaloxidation reactions occur via oxidative addition to the metal. Is this the likely path for the alkyl-zirconium oxidation reactionsor is another mechanism likely? Explain.Since the Zr of alkyl-zirconium complexes is at the +4 oxidation state, it can not be oxidized any more, therefore theoxidation of alkyl-zirconium complexes probably goes by another mechanism.ref. J. Schwartz et al. JACS 1975, 97,