Tetrasupersilyldialuminum [(t-Bu)3Si]2Al−Al[Si(t-Bu)3]2: The Dialane(4) with the Longest Al−Al Bond to Date,

Reaction of AlX 3 (X = Cl, Br) with R*Na (R* = supersilyl, Si( t -Bu) 3 ) in heptane at room temperature gave the ruby dialane R* 2 Al−AlR* 2 ( 1 ). X-ray structure analysis showed it to contain a Si 2 Al−AlSi 2 skeleton with D 2 d symmetry and the longest Al−Al bond to date (2.751(2) Å). Water- and air-sensitive 1 reacts with iodine or hydrogen to form R* 2 AlI or R* 2 AlH, respectively. Thermolysis and photolysis transform 1, via [R* 2 Al−AlR*] •, into the tetraalatetrahedrane Al 4 R* 4 .