Reactivity of ZrCl4 and HfCl4 with silylamines and thermal decomposition of the compounds [MCl4{NH(R)(SiR′3)}] (M = Zr, Hf, R = tBu, R′ = Me; R = SiR′3 = SiMe3, SiMe2H)

The Lewis acid/base adducts [MCl4{NH(R)(SiR′3)}] (M = Zr, Hf; R = tBu, R′ = Me; R = SiR′3 = SiMe3, SiMe2H) were synthesized by the 1:1 reaction of MCl4 with NH(R)(SiR′3) in dichloromethane solution at room temperature. The decomposition of [MCl4{NH(R)(SiR′3)}] proceeds with the elimination of R′3SiCl, as shown by thermogravimetric analysis. Pyrolysis of the compounds at 620 °C under inert conditions (N2, vacuum) afforded powders of composition [ClMN] or [Cl2MNH]. Preliminary low pressure chemical vapour deposition experiments show that [MCl4{NH(R)(SiR′3)}] deposits thin films of metal nitride contaminated with metal oxide.

Graphical abstractPyrolysis of the Lewis acid/base adducts [MCl4{NH(R)(SiR′3)}] (M = Zr, Hf; R = tBu, R′ = Me; R = SiR′3 = SiMe3, SiMe2H) afforded powders of composition [ClMN] or [Cl2MNH], where low pressure CVD yielded amorphous metal nitride films contaminated with oxide, C and Cl.Figure optionsDownload full-size imageDownload as PowerPoint slide