115385-07-4Relevant articles and documents
Kinetics and mechanisms of the reactions of diaryl- and dialkylgermylenes with alcohols and ethers in solution
Leigh, William J.,Lollmahomed, Farahnaz,Harrington, Cameron R.,McDonald, Jacklyn M.
, p. 5424 - 5434 (2006)
The reactions of methanol, tert-butanol, and THF with a series of simple germylene derivatives-dimethyl- (GeMe2), diphenyl- (GePh 2), and dimesitylgermylene (GeMes2; Mes = 2,4,6-trimethylphenyl)-have been studied in hexane solution at 25 °C by laser flash photolysis methods. The results are consistent with rapid, reversible reaction to form weakly stabilized Lewis acid-base complexes, which exhibit UV absorption maxima in the range 290-360 nm and decay with mixed order kinetics with concomitant formation of the corresponding digermene, Ge 2R4 (R = Me, Ph, or Mes). Absolute rate constants for formation of the complexes could be measured for GePh2 with all three substrates and for GeMe2 with THF and were found to vary over the range (4-10) × 109 M-1 s-1. Equilibrium constants were measured in all cases; they vary between 1.2 and 15 M -1 for GeMes2, decreasing in the order MeOH > t-BuOH > THF, while those for GeMe2 and GePh2 are 2-4 orders of magnitude larger and decrease in the order THF > MeOH > t-BuOH. For a given substrate, the equilibrium constants are consistently larger for GePh 2 than for GeMe2, reflecting the greater ability of phenyl compared to methyl substituents to stabilize negative charge at germanium in the zwitterionic complexes. In spite of the differences in the stabilities of the complexes, the rate constant for complexation with THF is almost twice as large for GeMe2 than for GePh2. The results indicate that the O - H insertion reaction of germylenes with alcohols proceeds via initial, reversible Lewis acid - base complexation, followed by slow proton transfer from oxygen to germanium, most likely via a catalytic route.
Reactivity of sulfonyl-containing compounds with ditetrelenes
Tashkandi, Nada Y.,Bourque, Jeremy L.,Baines, Kim M.
, p. 15451 - 15457 (2017/11/21)
The addition of a variety of sulfones and a sulfoxide to ditetrelenes (a disilene and a digermene) was examined. The reaction of benzenesulfonyl chloride with tetramesityldisilene or tetramesityldigermene results in the formation of the 1,2-addition products, 2-chlorotetramesityldisilyl- or digermylbenzenesulfinate. The addition of p-toluenesulfonyl chloride to the disilene gave the analogous product, 2-chlorotetramesityldisilyl p-toluenesulfinate. In contrast, benzenesulfonyl fluoride, diphenyl and dimethyl sulfone did not react with either the disilene or the digermene. The unprecedented formation of the sulfinates reveals a selective 2-electron reduction of the sulfur centres using ditetrelenes. The addition reactions of sulfonyl compounds illustrates the potential of ditetrelenes to serve as reducing agents which react rapidly, at room temperature under mild conditions. The reaction of tetramesityldisilene with diphenyl sulfoxide resulted in the formation of tetramesityloxadisilirane and with benzene sulfonic acid resulted in the formation of 1,1,2,2-tetramesityldisilyl benzenesulfonate.
On the synthesis, structure, and reactivity of tetramesityldigermene
Hurni, Krysten L.,Rupar, Paul A.,Payne, Nicholas C.,Baines, Kim M.
, p. 5569 - 5575 (2008/10/09)
Tetramesityldigermene (1) can be synthesized cleanly and quantitatively by photolysis of hexamesitylcyclotrigermane (2) in THF at low temperature. A solution of tetramesityldigermene (1) in THF is stable for several weeks at room temperature; the digermene does not dissociate or rearrange. The molecular structure of tetramesityldigermene (1) has been determined using X-ray crystallography. The effectiveness of the new protocol for the synthesis of tetramesityldigermene (1) and its derivatives has been demonstrated in the study of the addition of carboxylic acids to tetramesityldigermene (1).
