INDIUM(III) HALIDE-3,5-DI-TERT-BUTYL-O-BENZOSEMIQUINONE SYSTEMS

The reaction of InX(3) (X = Cl, Br, I) with 2 moi of Na+TBSQ(.-) (TBSQ(.-) = 3,5-di-t-butyl-o-benzosemiquinonate anion) yields solutions of the diradicals InX(TBSQ)2, whose EPR spectra have been recorded. Addition of pyridine or gamma-picoline (=L) to such solutions produces adducts of the 3,5-di-t-butylcatecholate-indium(III) halide, of the type In(TBC)XL(n). The mechanism of these reactions, and of the related ligand replacement and disproportionation equilibria, is discussed in terms of internal one-electron transfer processes. The compound In(TBC)(pic)(2).DMF has been the subject of an X-ray crystallographic study. The substance forms monoclinic crystals, space group P2(1)/n with a=12.992(5), b=13.923(4), c=18.491(4) Angstrom, beta=98.82(2)degrees, Z=4, R=0.053 for 3244 unique reflections. The molecule is dimeric, with a central In2O2 ring, involving six-coordinate indium(Ill).