Journal article

Gas-Phase Formation and Fragmentation Reactions of the Organomagnesates [RMgX2](-)

George N Khairallah, Charlene CL Thum, Denis Lesage, Jean-Claude Tabet, Richard AJ O'Hair



A range of mononuclear organomagnesates [RMgX2]- were generated in the gas phase by decarboxylation of the magnesium carboxylate precursors [RCO2MgX2]- (R = Me, Et, Pr, iPr, tBu, vinyl, allyl, HCî - C, Ph, PhCH2, PhCH2CH 2; X = Cl, Br, I). The gas-phase formation and unimolecular reactivity of these organomagnesates were examined using a combination of experiments carried out in linear ion trap and triple-quadrupole mass spectrometers and DFT calculations. Halide loss was found to directly compete with decarboxylation in the formation of mononuclear [RMgX2] -. However, sterically unhindered, stable R- substituents and strong Mg-Cl bonds can be employed to facilitate the decarboxylation react..

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Awarded by ARC

Funding Acknowledgements

We thank the ARC for financial support via Grant Nos. DP0558430 (to R.A.J.O.), DP1096134 (to G.N.K.) and DP110103844 (to R.A.J.O. and G.N.K) and through the Centres of Excellence Program. VICS is acknowledged for the Chemical Sciences High Performance Computing Facility (Gomberg). G.N.K. thanks the Australian Academy of Science for a Europe travel fellowship and JCT for a visiting scientist award at UPMC. We thank Dr. Tom Waters for useful discussions and Ann Jacob for carrying out preliminary calculations.