Pyrolytic Conversion of Precursors Prepared in Ti(NMe₂)₄-Diamine Systems

Precursors possessing Ti-N bonds were prepared by the reactions between Ti(NMe₂)₄ and each of three diamines H₂NCH₂CH₂NH₂, Me(H)NCH₂CH₂N(H)Me, HN(CH₂CH₂)₂NH (Ti(NMe₂)₄:diamine = 1:2), and were converted into ceramics by pyrolysis. The reactions with H₂NCH₂CH₂NH₂ and HN(CH₂CH₂)₂NH led to the formation of insoluble solids, whereas a soluble oil was obtained by the reaction with Me(H)NCH₂CH₂N(H)Me. The pyrolyses under argon gave carbon-rich Ti(N,C,O) phases, but those under NH₃- N₂ resulted in the formation of Ti(N,C,O) phases with higher nitrogen contents. Despite the difference in precursor structures the pyrolysis behavior of three precursors under argon was rather similar, suggesting that the precursor obtained from Me(H)NCH₂CH₂N(H)Me was effectively cross-linked during pyrolysis.