Disulfonated xantphos for mass spectrometric mechanistic analysis

Xantphos is a wide bite angle bisphosphine ligand that finds application in catalysis. Tracking its behavior during reactions under realistic reaction conditions can be difficult at low concentrations, and although electrospray ionization mass spectrometry (ESI-MS) effective real-time monitoring of catalytic reactions, it only observe ions. Accordingly, we experimented with the dianionic disulfonated version xantphos as charged tag for mechanistic analysis. It proved to behave exactly hoped, providing good intensity enabled direct study both an initial binding event (to copper, very fast) subsequent transfer another metal (palladium). Its nature makes especially promising which metals change charge state, because cationic complex anionic invisible zwitterion, whereas would instead make same appear due overall ?1. As such, holds genuine promise probe real time analysis using spectrometry.