Given that aluminyl compound K2[(NON)Al]2 reacts with trimethylsilyl azide to form a tetrazene complex by the uptake of two equivalents of substrate, we targeted the use of more sterically demanding silyl substituents to generate isolable aluminium silylimide compounds. We hypothesized that the cycloaddition of a second equivalent of azide would be less facile in the presence of greater steric bulk. Accordingly, the reaction of K2[(NON)Al]2 with triphenylsilyl azide in benzene leads to the rapid evolution of gas and the rapid precipitation of fine needles of the target imide K[(NON)Al{N(SiPh3)}], K[1a], as determined by H NMR spectroscopy and X-ray crystallography (Scheme 2 and Figure ). Pr methine signal at dH = 3.92, 2.87 ppm). Single crystals of the product K[1a] can be studied by X-ray crystallography, and although the quality of the data means that caution must be exercised with the structural metrics, the formation of the anionic [(NON)Al{N(SiPh3)}] -unit, bridged by K + cations (to give a 1-D coordination polymer) is unequivocally demonstrated (Figure ). K[1a] is sparingly soluble in hydrocarbon solvents, and attempts to dissolve it in THF lead immediately to the activation of the solvent via C-H bond cleavage across the Al-N bond, affording K[(NON)Al{NH(SiPh3)}(C4H7O)], K [2]. As such, K[1a] can be characterised by H NMR and X-ray diffraction only. The activation of THF in this way, effectively via deprotonation, mirrors the previously reported benzylic activation of toluene by the putative imide K[(NON)Al{N(SiMe3)}], and speaks to the strongly basic nature of the imide nitrogen.