New Germanium Complexes Containing Ligands Based on 4,6-Di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone in Different Redox States

• Published in: European Journal of Inorganic Chemistry 2008-03, Vol.2008 (9), p.1435-1444
• Main Authors: Piskunov, Alexandr V., Aivaz'yan, Igor A., Poddel'sky, Andrey I., Fukin, Georgii K., Baranov, Evgenii V., Cherkasov, Vladimir K., Abakumov, Gleb A.
• Format: Article
• Language: English
• Subjects: EPR spectroscopy; Germanium; Metallacycles; N,O ligands; O ligands; X-ray diffraction
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.200701115

The exchange reaction of lithium o‐amidophenolate, (AP)Li2, derived from the reaction of 4,6‐di‐tert‐butyl‐N‐(2,6‐diisopropylphenyl)‐o‐iminobenzoquinone (imQ) with GeCl4 in hexane or thf leads to (AP)2Ge (1) (AP is a dianion of imQ). The latter was also obtained by the interaction of GeCl2·dioxane and (ISQ)Li in toluene (ISQ is a radical anion of imQ). The reaction of (AP)Li2 with GeCl2·dioxane in thf results in the formation of germylene 2, [(AP)Ge (2)], which reduces neutral imQ to give compound 1. The exposure of 1 in thf to anhydrous HCl in a 1:1 molar ratio leads to its o‐aminophenolato derivative, (AP)(APH)GeCl (3). Free imQ inserts into the Ge–H bond of (C6F5)3GeH in thf to give (C6F5)3Ge(APH) (4). It is another way of obtaining complexes with protonated ligands such as APH. Compound 3 can be easily oxidized by air to form the stable paramagnetic complex (AP)(ISQ)GeCl (5). Complexes 1 and 3–5 were structurally investigated by using single‐crystal X‐ray diffraction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) It has been shown that a bulky aryl‐substituted o‐iminoquinone can serve as a versatile ligand that can be used to synthesize both divalent and tetravalent germanium amidophenolate derivatives. At the same time, the ligand coordinated to the germanium atom can be transformed from the dianion to the radical anion or protonated anion forms.