Stannylplumbylenes: bonding between tetravalent tin and divalent lead.

Depending on stoichiometry, reactions of the mixed valence Sn(0)/Sn(III) compound Sn(SnAr(3))(2) (1) (Ar = C(6)H(4)(O(i)Pr)(2)-2,6) with the likewise substituted plumbylene PbAr(2) (3) afforded either the homoleptic distannylplumbylene Pb(SnAr(3))(2) (4) or the heteroleptic arylstannylplumbylene Pb(Ar)SnAr(3) (5), a valence isomer of a stannaplumbene.

A stable and crystalline triarylgermyl radical: structure and EPR spectra.

A radical thing: After being obtained unexpectedly in low yields, the synthesis of the first stable triarylgermyl radical (*)Ge[3,5-tBu(2)-2,6-(EtO)(2)C(6)H](3) (1; C gray, O blue) was considerably optimized, and the product was investigated by X-ray analysis and EPR spectroscopy. The results were compared with DFT-MO studies for the model compound (*)Ge[2,6-(MeO)(2)C(6)H(3)].

[(OtBu)(2)C(6)H(3)](3)Ge(+) a free germyl cation with aryl ligands.

The reaction of Ar(3)GeBr (Ar = 2,6-(OtBu)(2)C(6)H(3)), which is the side product of the synthesis of the metalloid germanium cluster compound Ge(8)Ar(6), with the silver salt of the weakly coordinating anion (WCA) [Al(OR(f))(4)](-) (R(f) = C(CF(3))(3)) gives the free germyl cation Ar(3)Ge(+). Quantum chemical calculations open an insight into the bonding situation of this first free cation exhibiting aryl ligands and a first reaction leading to Ar(3)GeOH is presented.

Ge8R6: the ligands define the bonding situation within the cluster core.

The disproportionation reaction of Ge(i) halides open up a way to cluster compounds with an average oxidation state of the germanium atoms inside the cluster core in between 0 and 1. Simultaneously compounds with germanium in an oxidation state greater than i are formed. During the reaction of Ge(i) bromide with one equivalent of LiR (R = 2,6-(tBuO)(2)C(6)H(3)) the cluster compound Ge(8)R(6) and the molecular Ge(iv) compound R(3)GeBr were isolated, representing the reduction and the oxidation product of the disproportionation reaction, respectively.