Collision-induced dissociations of deprotonated phosphorus esters. Specific proton transfer accompanying fragmentation

Abstract

The collision-induced dissociations of deprotonated phosphorus esters are dominated by elimination of neutral species from the alkoxy groups with accompanying proton rearrangement. For example, [(MeO)₂P(CH₂)(O)]^– eliminates CH₂O and CH₂ with specific proton transfer to carbon to produce, respectively, (MeO)(Me)PO^– and (MeO)(Me)PO₂^–, whilst [(EtO)₂P(CH₂)(O)]^– similarly eliminates MeCHO and C₂H₄. The loss of C₂H₄ from this ion occurs by the competitive losses of CH₂CH₂ and MeCH; both losses form the product ion Me(EtO)PO₂^–. Thus neutral eliminations are accompanied by specific proton transfer to carbon.