Titanium(IV)azido and imido complexes as potential precursors to titanium nitride

Synthetic and structural studies have been performed for two imido complexes of titanium(IV). The reaction between [{Ti(NBut)Cl-2(NH2But)(2)}(3)] and 6 equivalents of Me3SiN3 at room temperature in the presence of pyridine resulted in the substitution of only one chloride per titanium atom and formation of the dimeric complex [{Ti(NBut)Cl(N-3)(py)(2)}(2)] (py = pyridine). An alternative approach to such complexes, which involved the reaction between [Ti(NMe2)(2)(N-3)(2)(py)(2)] and 1 equivalent of CyNH2 at room temperature, resulted in the dimeric bis(azide) complex [{Ti(NCy)(N-3)(2)(py)(2)}(2)] (Cy = cyclohexyl). The two new complexes have been characterised by X-ray crystallography; the solid state of each comprises dimeric units in which the two titanium atoms are bridged by a pair of azide ligands. A gas-phase pyrolysis study has been conducted on [Ti(NMe2)(2)(N-3)(2)(py)(2)] and preliminary CVD experiments on the two new complexes revealed that they are not effective titanium nitride precursors.