β−Diketiminate Ligand Supported Group 2 Metal Hydroxide, Halide, Oxygen Bridged Heterobimetallic and Heterotrimetallic Complexes: Synthesis and X-ray Structural Studies

Abstract

This PhD thesis describes the synthesis and structural characterization of group 2 metal hydroxide, halide, oxygen bridged heterobimetallic and heterotrimetallic complexes supported with the β-diketiminate ligand L (L = CH{(CMe)(2,6-iPr2C6H3N)}2). The first part of the thesis describes the controlled hydrolysis of alkaline earth metal amides LMN(SiMe3)2 nTHF (M = Mg, n = 0; M = Ca, n = 1) with water to afford the corresponding hydroxides [LM(OH) THF]2 (M = Mg, Ca) as air and moisture sensitive compounds. The presence of sterically bulky β-diketiminate ligands prevents self-condensation reaction in these hydroxides. Single crystal X-ray analysis shows that the hydroxides are dimeric in the solid state. The syntheses of magnesium chloride and calcium fluoride complexes are discussed in the second part of the thesis. As revealed by the crystal structure, LIMgCl (LI = CH{Et2NCH2CH2N(CMe)}2) is a solvent free and monomeric magnesium chloride complex that is analogues to the Grignard reagent. The first example of a soluble calcium monofluoride [LCa(F) THF]2 is obtained from the reaction of LCaN(SiMe3)2 THF with Me3SnF and its utility in surface coatings have been demonstrated. The third part deals with the synthetic route to obtain heterobimetallic and trimetallic oxgen bridged complexes with group 2, 13 and 14 elements. These include compounds with Mg−O−Al, Ca−O−Al, Al−O−Mg−O−Al, and Al−O−Sn−O−Al structural motifs. The last part deals with the synthesis of the first heterotrimetallic oxygen bridged system with three different metal atoms namely aluminum, magnesium, and zirconium.