84174-04-9Relevant academic research and scientific papers
Transient and Matrix Ultraviolet Absorption Spectra of Dimethylgermylene (Dimethylgermanediyl)
Tomoda, Shuji,Shimoda, Masakatsu,Takeuchi, Yoshito,Kajii, Yoshizumi,Obi, Kinichi,et al.
, p. 910 - 912 (2007/10/02)
Dimethylgermylene (1), generated from a new precursor dimethylbis(phenylseleno)germane (2), has been observed as a transient species by time-resolved laser flash photolysis at room temperature.
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.
Chemistry of Heavy Carbene Analogues R2M (M = Si, Ge, Sn). 8. Germylenes: Singlets or Triplets? Cheletropic Cycloadditions of Me2Ge and GeI2 to Conjugated Dienes
Schriewer, Michael,Neumann, Wilhelm P.
, p. 897 - 901 (2007/10/02)
Thermally generated germylenes Me2Ge undergo in solution under mild conditions (70-150 deg C) concerted 1,4-additions of the linear cheletropic type to certain 1,3-dienes.Thus, the highly reactive meso diallene 10a gives, in a about 1:1 ratio, only the two isomeric 1-germacyclopentenes 11a and 11b expected from front- and back-side attack of Me2Ge, whereas the D,L-diallene 10b produces only the third isomer, 11c, in accordance with this mechanism.The yields are about 70percent; the isomer purity is >/= 98percent.Likewise, two other E,E-1,4-disubstituted 1,3-butadienes give only the corresponding cis-2,5-disubstituted 1-germacyclopentenes 7a or 9a in 80percent or 30percent yields with an isomer purity of >/= 98percent (limit of the NMR analysis).Similarly, with GeI2 and 10a, only 14a and 14b are found, and 14c with 10b, as expected for a cheletropic reaction.Methylation of 14a-c yields the corresponding compounds 11a-c.Other mechanisms for these 1,4-additions are discussed but are highly unlikely: thermal germylenes Me2Ge and Ge2I behave as singlets.
