693228-13-6Relevant academic research and scientific papers
Reactivity of Ar′GeGeAr′ (Ar′ = C6H 3-2,6-Dipp2, Dipp = C6H 3-2,6-iPr2) toward Alkynes: Isolation of a Stable Digermacyclobutadiene
Cui, Chunming,Olmstead, Marilyn M.,Power, Philip P.
, p. 5062 - 5063 (2004)
The first reactions of the digermyne Ar′GeGeAr(Ar′ = C6H3-2,6-Dipp2, Dipp = C6H3-2,6-iPr2) with alkynes are reported. 1 reacts with 1 equiv of H5C6CCC6H5 to afford the 1,2-digermacyclobutadiene 2 in high yield, while it reacts with 2 equiv of the less hindered alkyne Me3SiCCH to yield an unexpected bicyclic compound 3. Molecular structures of 2 and 3 were determined by X-ray crystallography. A possible mechanism for the formation of 3 is discussed. The high reactivity of 1, even at room temperature, emphasizes the fundamental differences between the GeGe and CC multiple bonds. Copyright
Reactions of the heavier group 14 element alkyne analogues Ar′EEAr′ (Ar′ = C6H3-2,6(C 6H3-2,6-Pri2)2; E = Ge, Sn) with unsaturated molecules: Probing the character of the EE multiple bonds
Cui, Chunming,Olmstead, Marilyn M.,Fettinger, James C.,Spikes, Geoffrey H.,Power, Philip P.
, p. 17530 - 17541 (2007/10/03)
Reactions of the alkyne analogues Ar′EEAr′ (Ar′ = C 6H3-2,6(C6H3-2,6-Pri 2)2; E = Ge (1); Sn (2)) with unsaturated molecules are described. Reaction of 1 and 2 with azobenzene afforded the new hydrazine derivatives Ar′E{(Ph)NN(Ph)}EAr′ (E = Ge (3); Sn (4)). Treatment of 1 with Me3SiN3 gave the cyclic singlet diradicaloid Ar′Ge{μ2-(NSiMe3)}2GeAr′ (5), whereas 2 afforded the monoimide bridged Ar′Sn{μ2- N(SiMe3)}-SnAr′ (6). Reaction of 1 with t-BuNC or PhCN yielded the adduct Ar′GeGe(CNBui)Ar′ (7) or the ring compound Ar′Ge-N(Ph)CC(Ph)N-GeAr′ (8). In contrast, the tin compound 2 did not react with either t-BuNC or PhCN. Treatment of 1 with N 2CH(SiMe3) generated Ar′Ge{μ2- CH(SiMe3)}{μ2:η2-N 2CH(SiMe3)}{μ2-N2-CH(SiMe 3)}GeAr′ (9) which contains ligands in three different bridging modes and no Ge-Ge bonding. Reaction of 1 with an excess of N2O gave a germanium peroxo species Ar′(HO)Ge(μ2-O) (μ2:η2-O2)Ge-(OH)Ar′ (10) which features a Ge-O-Ge-O-O ring. Oxidation of 1 by tetracyanoethylene (TCNE) led to cleavage of the Ge-Ge bond and formation of a large multiring system of formula Ar′Ge3+{(TCNE)2-}3- {(GeAr′) +}3. The digermyne 1 also reacted with 1 equiv of Ph≡CPh to give the 1,2-digermacyclobutadiene 12, which has a Ge-C-C-Ge ring, and with Me3SiC≡CH or PhC≡C-C≡CPh to activate a flanking C6H3-2,6-Pri2 ring and give the tricyclic products 13 and 14. The distannyne 2 did not react with these acetylenes. Overall, the experiments showed that 1 is highly reactive toward unsaturated molecules, whereas the corresponding tin congener 2 is much less reactive. A possible explanation of the reactivity differences in terms of the extent of the singlet diradical character of the Ge-Ge and Sn-Sn bonds is discussed.
