In the glovebox, (P 2 O 5 ) ∞ (0.26 g, 1.8 mmol) was suspended in acetonitrile (10 mL). To this stirring suspension was added a solution of DABCO (0.82 g, 7.3 mmol) in acetonitrile (2 mL). The resulting mixture was stirred for 5 min, resulting in dissolution of most of the solid material. The mixture was then filtered through Celite® to remove any insoluble impurities.