Persistent radicals of trivalent tin and lead.

In this report we present synthetic, crystallographic, and new electron paramagnetic resonance (EPR) spectroscopic work that shows that the synthetic route leading to the recently reported, first persistent plumbyl radical *PbEbt3 (Ebt = ethylbis(trimethylsilyl)silyl), that is, the oxidation of the related PbEbt3-anion, was easily extended to the synthesis of other persistent molecular mononuclear radicals of lead and tin. At first, various novel solvates of homoleptic potassium metallates KSnHyp3 (4a), KPbHyp3 (3a), KSnEbt3 (4b), KPbIbt3 (3c), and KSnIbt3 (4c) (Hyp = tris(trimethylsilyl)silyl, Ibt = isopropylbis(trimethylsilyl)silyl), as well as some heteroleptic metallates, such as [Li(OEt2)2][Sn(n)BuHyp2] (3d), [Li(OEt2)2][Pb(n)BuHyp2] (4d), [Li(thf)4][PbPhHyp2] (3e), and [K(thf)7][PbHyp2{N(SiMe3)2}] (3f), were synthesized and crystallographically characterized. Through oxidation by tin(II) and lead(II) bis(trimethylsilyl)amides or the related 2,6-di-tert-butylphenoxides, they had been oxidized to yield in most cases the corresponding radicals.