TRIPODAL AMIDES CONTAINING A TOTALLY SILICON-BASED LIGAND FRAMEWORK

A novel type of tripodal amido ligand with a totally silicon-based (trisilylsilane-derived) ligand framework has been synthesized and coordinated to tetravalent titanium and zirconium. The key compound in the Ligand synthesis is the chlorosilane H3CSi{Si(CH3)(2)Cl}(3) (2) which upon condensation with a range of primary amines R-NH2 (R = aryl, alkyl) yields the amino-functionalized ligand precursors H3CSi{Si(CH3)(2)NHR}(3) (3a-e). Their corresponding trilithium salts have been found to be the appropriate amide transfer reagents in the subsequent syntheses of the transition metal complexes. Single-crystal X-ray structure analyses of the trilithium triamide H3CSi{Si(CH3)(2)N(Li)tBU}(3) (4a) and the Ti complex H3CSi{Si(CH3)(2)N(p-Tol)}3TiBr (5b) have established their respective adamantane- and [2.2.2]bicyclooctane-related cage structures.