The Monomeric Alanediyl :AlAriPr8 (AriPr8 = C6H-2,6-(C6H2-2,4,6-Pr3i)2-3,5-Pr2i): An Organoaluminum(I) Compound with a One-Coordinate Aluminum Atom

Reduction of the aluminum iodide AlI2AriPr8 (1; Ar-iPr8 = C6H-2,6-(C6H2-2,4,6-Pr-3(i)) 2 -3,5-Pr-2(i)) with 5% w/w Na/NaCl in hexanes gave a dark red solution from which the monomeric alanediyl :AlAriPr8 (2) was isolated in ca. 28% yield as yellow-orange crystals. Compounds 1 and 2 were characterized by X-ray crystallography, electronic and NMR spectroscopy, and theoretical calculations. The Al atom in 2 is one-coordinate, and the compound displays two absorptions in its electronic spectrum at 354 and 455 nm. It reacts with H-2 under ambient conditions to give the aluminum hydride {AIH(mu-H)Ar-iPr8}(2), probably via a weakly bound dimer of 2 as an intermediate.