Synthesis and structures of aluminium monohydride and chalcogenides bearing a bidentate [N,O] ligand

The aluminium monohydride (3-tBu-5-Me-2-(O)C6H2CH2-N-2,6-iPr(2)C(6)H(3))AlH(NMe3) (2) was prepared by treatment of the bidentate salicylaldimine [3-tBu-5-Me-2-(OH)C6H2CH=N-2,6-iPr(2)C(6)H(3)] (1) with a small excess of AlH3.NMe3 in high yield. Compound 2 reacted with sulfur and selenium respectively to afford the dimeric aluminium chalcogenide [(3-tBu-5-Me-2-(O)C6H2CH2-NH-2,6-iPr(2)C(6)H(3))Al(mu-E)](2) [E = S (3), E = Se (4)]. During the formation of 2 hydrogen migration from the aluminium centre to the ligand backbone occurred. A possible reaction mechanism for 3 and 4 is discussed and the molecular structures of compounds 2-4 were determined by X-ray structural analyses.