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Reactions of organotin chlorides R 2 SnCl 2 (R = Et, Bu t , or Ph) with lithium 4,6 di(tert butyl) N (2,6 diisopropylphenyl) o amidophenolate. Synthesis and structures of tin(IV) o iminoquinone complexesThe exchange reactions of tin diorganohalides R 2 SnCl 2 (R = Et, Bu t , or Ph) with lithium amidophenolate APLi 2 (AP is the 4,6 di(tert butyl) N (2,6 diisopropylphenyl) o iminobenzo quinone dianion) in tetrahydrofuran produced the new five coordinate (Et 2 SnAP(THF) (3)) and four coordinate (R 2 SnAP (R = Bu t , Ph)) tin(IV) complexes. The reaction of Ph 2 SnCl 2 with APLi 2 in a nonpolar solvent (hexane or toluene) is accompanied by the additional redox process giving rise to the paramagnetic complex Ph 2 Sn(ImSQ)Cl (6) (ImSQ is the 4,6 di(tert butyl) N (2,6 diisopropylphenyl) o iminobenzoquinone radical anion). The molecular struc tures of complexes 3 and 6 were established by X ray diffraction.

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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)

The reactions of stable germylenes-1-germa-2,5-diaza-3-cyclopentene derivatives-with 3,6-di-tertbutyl-2-ethoxyphenoxyl and mercury(II) halides in toluene were studied. EPR revealed the formation of new paramagnetic germylene complexes in solutions.The profound interest in the chemistry of low-coordination silicon(II), germanium(II), and tin(II) complexes stems, first of all, from their high reactivity with respect to very different substrates [1][2][3][4][5]. A new line of investigation in this area is the study of low-valence derivatives of Group 14 elements with paramagnetic ligands. The EPR spectra of such complexes can provide rich information on their structures and mechanisms of transformation. The first compounds of this type have been recently reported [6][7][8]. The first crystalline paramagnetic germylene containing the radicalanion acenaphthenediimine ligand was obtained and isolated in [6]. The first paramagnetic stannylenes stable in toluene solutions over a period of several days were obtained by the exchange reaction of tin(II) chloride with some radical-anion lithium diazabutadiene salts [7]. Fixation of some radical species by diamagnetic N-heterocyclic silicon(II) derivatives was reported in [8]. EPR shows that these reactions lead to the formation of unstable silicon(II) derivatives bearing an unpaired electron. Reactions of analogous germylenes with nitroxyl radicals yield only diamagnetic products [9].Here, we report on the first example of generation of paramagnetic three-coordinate germylenes based on diazabutadiene heterocycles in solutions. Radical complexes were obtained by oxidation of substituted 1-germa-2,5-diaza-3-cyclopentenes with mercury halides, as well as by the reaction of the former with the 3,6-di-tert -butyl-2-ethoxyphenoxyl radical.Initial germylenes 1a -1f were obtained as described in [10]. 3,6-Di-tert -butyl-2-ethoxyphenoxyl radical was generated in a solution upon dissociation of the corresponding dimer [11]. EPR spectra were obtained on a Bruker ER 200D-SRC spectrometer (working frequency ~9.5 GHz) with an ER 4111VT variable temperature unit. The g values were determined using diphenylpicrylhydrazyl as the reference ( g = 2.0037). Hyperfine coupling (HFC) constants were obtained by simulation with the WinEPR SimFonia program.All operations for preparation of the complexes were carried out under conditions excluding air oxygen and moisture.It turned out to be impossible to obtain paramagnetic germylenes by the exchange reaction of germanium dichloride with radical-anion lithium diazabutadiene salts as described in [7]. This reaction yields only diamagnetic products. However, the products of the reaction of N , N '-di-tert -butyl-1-germa-2,5-diaza-3-cyclopentene (germylene 1a ) in toluene with mercury(II) chloride or bromide give rise to EPR spectra (Fig. 1). These spectra are well resolved due to small widths (0.08 mT at 290 K) of individual spectral components. The hyperfine structure (HFS) arises from hyperfine coupling of an unpaired electron to magnetic nuclei 1 H (...