REDUCTION PROPERTIES OF GERMANIUM DICHLORIDE WITH RESPECT TO THE REDOX-ACTIVE MONOIMINOACENAPHTENONE dpp-MIAN

Reaction of germanium dichloride [GeCl 2 (dioxane)] with 2-(2,6-diisopropylphenyl-imino)acenaphthylene-1-one (dpp-MIAN) leads to the reduction of dpp-MIAN and subsequent formation of the dianion bis-dpp-MIAN double ligand. Depending on the solvent, different products are formed. For example, reaction in toluene and diethyl ether yields digermylene [{(bis-dpp-MIAN)Ge (II) }Ge (II) Cl 2 ] ( 1 ) where the doubled ligand is bonded to the divalent germanium atom by oxygen atoms, while the GeCl 2 species is coordinated by an oxygen atom. Complex 1 forms two polymorphs, depending on crystallization conditions. Crystallization from toluene yields the 1m polymorph in the P 2(1)/ c monoclinic modification, while crystallization in diethyl ether yields the 1o polymorph in the Pbca orthorhombic modification. Reduction of dpp-MIAN by germanium dichloride in tetrahydrofuran yields the [(bis-dpp-MIAN) 2 Ge (IV) ] complex ( 2 ) containing tetravalent germanium. Compounds 1 (polymorphs 1m and 1o ) and 2 are characterized by IR spectroscopy, NMR, and XRD.