Reaction of N,N'-dimethylimidazolidine-2-selone (L) with I-2. Crystal structure of the mixed-valence (L center dot I-2)(L(2))(2+)center dot 2I(3)(-) compound

From the reaction of N,N'-dimethylimidazolidine-2-selone (L) with I-2 the mixed-valence (L . I-2)(L(2))(2+). 2I(3)(-) compound has been prepared. (L . I-2)(L(2))(2+). 2I(3)(-) consists of a neutral adduct between L and a diiodine molecule and a triiodide salt, whose dication is formed by two L molecules joined through an Se-Se bond. This is the first example of a dication bearing the -Se-Se- bridge obtained by direct oxidation of a selenic compound with diiodine. FT-IR and FT-Raman spectra agree well with the structural features. Crystals of (L . I-2)(L(2))(2+). 2I(3)(-) are triclinic, space group <P(1)over bar>, Z = 2, with unit cell dimensions a = 8.465(2), b = 10.233(3), c = 21.798(8) Angstrom, alpha = 95.81(3), beta = 90.53(2), gamma = 103.18(2)degrees, R = 0.027.