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)]m[HAlNEt]n; Allyl/Et-alanes}, have been prepared by reactions of lithium hydridoaluminate (LiAlH4) with a mixture of allylamine hydrochloride (CH2double bond; length as m-dashCHCH2NH2 · 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 Cdouble bond; length as m-dashC, 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.