107362-90-3Relevant academic research and scientific papers
Reactions of Diazo-compounds with the Electron-rich Germylene Ge2. Characterisation and Some Addition Reactions of 2GeNNC(COOMe)2: Crystal and Molecular Structure of 2Ge
Glidewell, Christopher,Lloyd, Douglas,Lumbard, Keith W.,McKechnie, James S.,Hursthouse, Michael B.,Short, Richard L.
, p. 2981 - 2988 (2007/10/02)
Two forms of the stable germyleneazine 2GeNNC(COOMe)2, formed by addition of the diazo-compound N2C(COOMe)2 to the electron-rich germylene Ge2 have been characterised in solution by 1H and 13C n.m.r. spectroscopy.MNDO calaculations on the simpler analogue 2GeNNC(COOMe)2 indicate that the two forms have planar transoid and cisoid GeNNC groups respectively, with the cisoid isomer as the more stable: the calculations also indicate that charge-controlled additions of electrophiles will occur at N1, adjacent to germanium, while all nucleophilic addition will occur at Ge.Some adducts of GeNNC(COOMe)2 with weak acids HX are described; in all cases 1,2-addition of HX occurs across the Ge-N1 bond to yield 2Ge(X).Crystals of one such adduct 2Ge are triclinic, space group P1-, with a = 9.627(2), b = 12.672(19), c = 15.702(3) Angstroem, α = 101.66(4), β = 85.02(2), γ = 77.65(5) deg, and Z = 2.The structure was refined from diffractometer data (5173 observed reflections) to an R value of 0.046.The structure determination confirms the 1,2-addition of HC(N2)COPh across the Ge-N1 bond of 2GeNNC(COOMe)2 and reveals a free diazo-group, sterically unconstrained.Reaction of tosyl azide with Ge follows a different course from the reactions involving diazo-compounds; nitrogen is lost and the product is a polygermazane 2GeNSO2C6H4Me-p>n, which is insoluble in aqueous media and all common organic solvents, wholly resistant to hot 50percent aqueous alkali, but readily hydrolysed by concentrated hydrochloric acid.
Formation of Germanium-Nitrogen Double Bonds in Reactions of the Electron-rich Germylene Bisgermanium(II) with a Range of Diazo-compounds
Glidewell, Christopher,Lloyd, Douglas,Lumbard, Keith W.
, p. 501 - 508 (2007/10/02)
The electron-rich germylene Ge2 reacts with the diazo-compounds R1CH2COC(N2)R2 1 = H, R2 = CO(OEt), SO2C6H4Me-p, or COPh; R1, R2 = -CMe2CH2C(O)->, which contain an enolisable function, to yield the heterocycles ; the weakly acidic diazo-compounds ethyl diazoacetate and diazoacetophenone yield bis-adducts Ge2 (R = OEt or Ph).Diazo-compounds containing two non-enolisable substituents yield mono-adducts with Ge2 which can be hydrolysed to yield the diol Ge(OH)22 and, in one example, the corresponding hydrazone H2NN=C(COPh)CO(OEt).These adducts appear to be thermodinamically stable in an aprotic solvent, but can be trapped by addition of ethanol, to yield Ge2(OEt)2>, or of diazoacetophenone to yield Ge22>.All the reactions of the germylene with diazo-compounds can be rationalised in terms of the initial formation of a germyleneazine 2Ge=N-N=C(X)Y, which readily adds any available protic species to give a germane derivative.MNDO calculations on model systems are in accord with the experimental findings and also explain their differences from results previously obtained using the simpler germylene GePh2.
