title: Electron-Transfer Processes in Indium(II) Iodide-o-Quinone Systems.
abstract: Indium(II) iodide reacts with various substituted o-quinones in nonaqueous solution by successive one-electron-transfer reactions to give (SQ)InI(2) products (SQ = semiquinonate radical anion). Electron spin resonance spectroscopy demonstrates the presence of both mono- and diradical species in the reaction mixture. Addition of 4-picoline to a mixture of In(2)I(4) and TBQ (=3,5-di-tert-butyl-o-quinone) in toluene causes the precipitation of the indium(III)-semiquinonate complex (TBSQ)InI(2)(pic)(2) whose structure has been established by X-ray crystallography: space group P&onemacr;, with a = 13.013(3) Å, b = 13.317(3) Å, c = 10.828(5) Å, alpha = 97.71(3) degrees, beta = 107.98(3) degrees, gamma = 103.92(3) degrees, V = 1684.8(1.2) Å(3), Z = 2. Refinement converged at R = 0.051 and R(w) = 0.064 for 5918 reflections at 23 degrees C. The InO(2)N(2)I(2) kernel is pseudooctahedral, and the structure confirms the presence of the semiquinonate ligand. A reaction scheme which incorporates these results is proposed.
authors.affiliation: Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4.
authors.forename: Martyn A.
authors.initials: MA
authors.lastname: Brown
authors.forename: Bruce R.
authors.initials: BR
authors.lastname: McGarvey
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ozarowski
authors.forename: Dennis G.
authors.initials: DG
authors.lastname: Tuck