The reaction between [AlH 3 (NMe 2 Et)] and 1 equiv. of t-BuSH resulted in the isolation of colourless crystals of [Al(S t-Bu) 3 (NMe 2 Et)]. The reaction of [AlH 3 (NMe 2 Et)] and 1 equiv. of 2,6-Me 2 C 6 H 3 SH afforded colourless crystals of [HNMe 2 Et][Al(SC 6 H 3 Me 2 -2,6) 4 ]. The related reaction of [AlH 3 (OEt 2 )] (generated in situ from AlCl 3 and 3 equiv. of LiAlH 4 ) and 2,6-Me 2 C 6 H 3 SH in diethyl ether resulted in the formation of [Al(SC 6 H 3 Me 2 -2,6) 3 (OEt 2 )]. However, the ionic compound [Li(OEt 2 ) 3 ][Al(SC 6 H 3 Me 2 -2,6) 4 ] can be isolated from the reaction between [AlH 3 (OEt 2 )] and 2,6-Me 2 C 6 H 3 SH, when incomplete reaction of AlCl 3 with LiAlH 4 occurs before the addition of the thiol. The X-ray crystal structures of all the compounds have been determined.