1730-66-1Relevant academic research and scientific papers
Digermylplatinum(II) organometallic rings L2PtGe(Me2)EGeMe2 [E = N-, O, S, (η-C5H4)2Fe]
Barrau,Rima,Cassano,Satgé
, p. 5700 - 5703 (2008/10/09)
The synthesis, reactivity, and characterization of the digermylplatinum(II) linear complexes (ClMe2Ge)2Pt(PPh3)2 (1) and (ClMe2Ge)2Pt(diphos) (2) and cyclic complexes (diphos)PtGe-(Me2)EGeMe2 [E = S (3), -NPh (4), (η5-C5H4)Fe(η5-C 5H4) (5), O (6)] are reported. The chemistry of 2-6 is illustrated through their reactions with phenylacetylene and N-methyltriazolinedione. Complexes 3 and 6 give double germylation of these unsaturated systems, while 2, by reaction with triazolinedione, gives the monogermylated complex Me2-(Cl)GePt(Cl)diphos and the dimer of the germylated heterocycle Me2GeNC(O)N(Me)C(O)N.
Formation of Halide Complexes of Methyl- and Inorganic Germanium(IV) in Aqueous Hydrohalogenic Acid Solutions
Sohrin, Yoshiki
, p. 3363 - 3371 (2007/10/02)
The reaction of methyl- and inorganic germanium(IV) hydroxides ((CH3)nGe(OH)4-n; n = 1, 2, or 3) with halide ions (X = Cl-, Br-, or I-) to form halide complexes ((CH3)nGeX4-n) in aqueous acidic solution has been investigated by liquid-liquid extraction, solid-liquid distribution (ion exchange), and 1H NMR spectrometry.It has been found that methylgermanium moieties are hard Lewis acids similarly to inorganic germanium(IV), because the stability constant of the halide complexes decreases in the order Cl- > Br- > I-.The stability constant for an X- ion increases as the number of methyl groups attached to the germanium atom increases.The species of inorganic-, monomethyl-, and dimethylgermanium are nonionic and have a tetrahedral structure in HX solution, and OJ- ions attached to the germanium atom are stepwise substituted by X- ions with an increase in HX activity.Trimethylgermanium alone forms a cation, when the activity of HX is not sufficiently high.These facts suggest that the transfer of a negative charge from methyl groups to the central germanium atom lowers the stability of the bond between the germanium atom (hard acid) and an OH- ion (hard base).
Direct Synthesis of Organobromogermanes from Methylenebromide
Schmidbaur, Hubert,Rott, Johann
, p. 285 - 287 (2007/10/02)
From the copper-catalyzed reaction of germanium powder with dibromomethane at 310 deg C a mixture of alkylbromogermanes is obtained.The major products are CH3GeBr3, Br3GeCH2Br (1), CH2(GeBr3)2 (2) and (CH2GeBr2)3 (3).The product distribution parallels the analogous reaction with dichloromethane reported previously.All compounds were characterized by analytical and spectroscopic data, and can be converted into the corresponding hydrides. - Keywords: Alkylbromogermanes, Synthesis, CVD Feeding Gas, Germanium/Copper Mixtures
Chemistry of heavy carbene analogues R2M (M = Si, Ge, Sn). 12. Concerted and nonconcerted insertion reactions of the germylene Me2Ge into the carbon-halogen bond
K?cher, Jürgen,Lehnig, Manfred,Neumann, Wilhelm P.
, p. 1201 - 1207 (2008/10/08)
During the reaction of Me2Ge with CCl3X (X = Cl, Br), PhCH2X (X = Br, I), and Ph2CHCl, 1H CIDNP is observed in the products of net insertion of Me2Ge into the carbon-halogen bond and in Me2GeX2 (X = Cl, Br). It is concluded that a two-step radical reaction takes place by an abstraction-recombination mechanism. No reaction takes place with alkyl halides that have a C-X bond dissociation energy of more than about 70 kcal/mol. Me2Ge is generated thermally at 70-95°C or photochemically from the 7-germabenzonorbornadiene 1 and reacts in both cases in the singlet state. The activation energy for forming Me2Ge from 1 is 19 kcal/mol for the reaction with CCl4. Insertion products are also formed with the alkenyl halides CH2=CHCH2X, PhCH=CHX (X = Cl, Br), and 2-bromobut-2-ene, but without showing CIDNP effects. Since Me2GeX2 was not found either, Me2Ge reacts in these cases in a nonradical manner. It does not react with 1-chlorocyclohexene, but it does react with Me2GeX2 under formation of digermanes and/or oligogermanes without CIDNP.
Germacyclopentanes via cycloadditions of free dimethylgermylene to styrenes
K?cher, Jürgen,Neumann, Wilhelm P.
, p. 400 - 402 (2008/10/08)
Free Me2Ge gives cycloadditions with 2 mol of α-substituted styrenes via a regiospecific but not stereospecific mechanism. Equal amounts of syn/anti 3,4-diphenylgermacyclopentanes are formed in good yield, those arising from α-substituted styrenes bearing additional substituents in these positions, and no 2,5- or 2,4-substituted rings. The 4,4,5,5-Ph4 derivative has an extraordinarily strained five-membered ring with a very long C3-C4 bond (1.626 A?) and αC-Ge-C = 90.3°. Styrenes without a =CH2 group as well as a number of other olefins do not react rapidly enough. A two-step mechanism involving an 1:1 adduct is suggested.
Insertion reactions of dimethylgermylene, Me2Ge, and their mechanisms as studied by CIDNP
K?cher, Jürgen,Lehnig, Manfred
, p. 937 - 939 (2008/10/08)
The insertion of germylenes into carbon-halogen bonds is shown to occur, in the case of thermally generated Me2Ge and benzyl bromide, via a cage abstraction-recombination reaction, giving typical 1H CIDNP effects proving the singlet state of Me2Ge. Besides, an abstraction reaction of escaped ·GeMe2Br yields Me2GeBr2 also showing 1H CIDNP effects, followed by an one-step insertion of Me2Ge into Ge-Br bonds of Me2GeBr2, giving oligogermanes without 1H CIDNP effects.
