4-t-BuN= PF, to be downfield of the equatorial PF signal for the corresponding electrically neutral fluorophosphoranes (1O-P-5), again showing an order of chemical shifts opposite to that predicted from charge alone. I0 The peak for fluorines on phosphorus is very broad because of PF5-PF6-exchange and is centered at 68.2 ppm. The mass spectrum of 3 shows a large peak (25% of the base intensity) at m/e 535 for M+-F, presumably the persulfonium ...