36147-87-2Relevant academic research and scientific papers
Generation, Thermodynamics, and Chemistry of the Diphenylcarbene Anion Radical (Ph2C.-)
McDonald, Richard N.,Gung, Wei Yi
, p. 7328 - 7334 (2007/10/02)
Dissociative electron attachment with Ph2C=N produced Ph2C.- (m/z 166).The reactions of Ph2C.- with potential proton donors of known gas-phase acidity were used to bracket PA(Ph2C.-) = 380 +/- 2 kcal mol-1 from which ΔHf0(Ph2C.-) = 81.8 +/- 2 kcal mol-1 was calculated.The reactions of Ph2C.- with CH3OH and C2H5OH proceeded with major and minor amounts, respectively, of a H2.+-transfer channel, forming Ph2CH2, RCHO, and an electron.The kinetic nucleophilicity of Ph2C.- in SN2 displacement reactions with CH3X and C2H5X molecules was shown to be medium, which requires a significant intrinsic barrier in these reaction.The reactions of Ph2C.- with various aldehydes, ketones, and esters were fast and established two principal product-forming channels: (1) H+ transfer if the neutral reactant contains activated C-H bonds and (2) carbonyl addition followed by radical β-fragmentation of one of the groups originally attached to the carbonyl carbon.The order for the ease of radical β-fragmentation in the tetrahedral intermediates was RO > alkyl >> H, and CO2CH3 > CH3.Since the reactions of Ph2C.- with the simple esters HCO2CH3 and CH3CO2CH3 were fast, it should now be possible to examine the reactions of carbonyl-containing organic molecules, which are expected to react slower than these esters and obtain their relative reactivities.
Gas-Phase Reactions of Anions with Substituted Silanes
DePuy, C. H.,Bierbaum, Veronica M.,Flippin, L. A.,Grabowski, Josef J.,King, Gary K.,et al.
, p. 5012 - 5015 (2007/10/02)
The gas-phase reactions of fluoride, amide, hydroxide, and methoxide ions with a variety of substituted silanes have been studied by the flowing afterglow technique.Fluoride reacts readily with trimethylsilyl derivatives to displace benzyl, alkenyl, and alkynyl anions.These reactions have also been used to generate specific structural isomers (CH3CC- and CH2C=C=CH-).Anions more basic than phenide ion cannot be produced in this manner, and their parent trimethylsilanes interact with fluoride by more complex mechanisms.Amide, hydroxide, and methoxide ions react with substituted trimethylsilanes by both displacement and proton abstraction whenever an acidic hydrogen is present; in the absence of displaceable groups and acidic hydrogen, the reactions of amide, hydroxide, and methoxide parallel those of fluoride ion.
