Coordination complexes and organometallic complexes of palladium and platinum with polydentate ligands containing pyrazole groups and related ligands: an electrospray mass spectrometric study

Abstract

Electrospray mass spectra have been obtained from methanol solution for a wide variety of organometallic compounds of palladium(IV,II) and platinum(IV) containing polydentate nitrogen donor ligands. In almost every case the intact ion was observed as the base peak, and often as the only peak, at low ion source energies emphasising the very soft nature of the transfer of ions from solution to the gas phase. Daughter ions were generated either by collisional activated decompositions involving solvent molecules within the ion source as the source energy was increased, or alternatively by tandem mass spectrometry using argon as the collision gas. The palladium(IV) complexes all undergo very facile reductive elimination of two methyl groups, as expected for palladium(IV) complexes. In contrast, platinum(IV) compounds retain their organo groups at low ion source energies.