Preparation and pyrolysis of poly(allyl iminoalane-co-ethyl iminoalane)s [HAlN(allyl)]m[HAlNEt]n

Poly(allyl iminoalane-co-ethyl iminoalane)s {HAlN(allyl)]_mHAlNEt]_n; Allyl/Et-alanes}, have been prepared by reactions of lithium hydridoaluminate (LiAlH₄) with a mixture of allylamine hydrochloride (CH₂CHCH₂NH₂ · HCl; allylNH₂ · HCl) and ethylamine hydrochloride (CH₃CH₂NH₂ · HCl; EtNH₂ · HCl) with various allyl/Et ratios. Spectroscopic analyses indicate that Allyl/Et-alane(1/3) (allyl/Et = 1/3) contains octamers possessing Al-H and C-H groups as well as CC, Al-N, and C-N bonds. The loss of aluminum during pyrolysis of Allyl/Et-alane(1/3) at 1600 °C under an Ar atmosphere is 15%, which is less than the value reported for the pyrolysis of poly(ethyliminoalane) (36%). The suppression can be ascribed to cross-linking reactions involving allyl groups (hydroalumination and polymerization of the allyl groups), judging from infrared (IR) and solid-state nuclear magnetic resonance (NMR) spectroscopy.