The reactions of zirconium isopropoxide with acetylacetone. benzoylacetone, dibenzoylmethane, and ethyl benzoylacetate have been studied and a number of new derivatives of the type M(OPri ), , , Lz (where M = Zr. L = acetylacetone, benzoylacetone, dibenzoylmethane. or ethyl benzoylacetate, x = 1 -4) have been isolated. These derivatives interchange their isopropoxy-for t-butoxy-groups when heated under reflux with t-butyl alcohol. Structures of these derivatives have been discussed on the basis of analysis, molecular weight, and i.r. spectral studies.
MORGANAND BOW EN,^ studied the reactions of zirconium tetrachloride with acetylacetone and benzoylacetone and isolated tris-(P-diket onat 0) zirconium monochloride. The preparation of t etrakisacet ylacet onat e and t etrakisbenzoylacetonate derivatives of zirconium in aqueous medium has been described by earlier worker^.^^^ Recently, Cox, Lewis, and Nyholm4 have described the preparation of p-diketone derivatives of Group IV tetrachlorides and have shown that zirconium forms three different classes of compounds, vix. Zr[(diketone)z Cl,] O, Zr [ (diketone),] + [FeClJ -, and Zr [ (diketone) 3C1]o.They have also shown that zirconium has a pronounced tendency to form seven-co-ordinate ZrL3C1 compounds (L = diketone) and a lesser tendency than titanium to form six-co-ordinate ML2X, or [ML,]+ compounds. The ready formation of eight-co-ordinate ZrL, is also reported. No attempts have been made to study the reactions of zirconium alkoxides with P-diketones and P-keto-esters in nonaqueous medium.In view of the reports on the isolation of alkoxy-pdiketonates of a number of metal^,^-^ the reactions of zirconium isopropoxide in benzene with various molar ratios of p-diketones and P-keto-esters have been carried out and the results are summarised in Table 1. The propan-2-01 produced was distilled off azeotropically and the progress of the reaction was followed by estimating the amount of propan-2-01 collected. The reactions appear to proceed readily. Mono-, di-, tri-, and tetrasubstituted products of the type Zr(OPri),-,L, (L = acetylacetone, benzoylacetone, dibenzoylmethane , or ethyl benzoylacetate; x = 1 4 ) have been isolated in almost quantitative yields.These reactions (involving probably an SN2 type of mechanism) may be represented by equation (1) where R1R2 = Me, Ph, and OEt, x = 1 4 .Alcoholysis of mono-, bis-, and tris-acetylacetone and -dibenzoylmethane derivatives of zirconium with excess of t-butyl alcohol in the presence of benzene provided a convenient method for the analysis of the isopropoxy-