26412-87-3 EINECS 247-683-3 NSC 75831 Pyridine compound with sulfur trioxide (1:1) Pyridine sulfotrioxide Pyridine, compd. with sulfur trioxide (1:1) Pyridine, compd. with sulfur trioxide (1:1) (8CI)(9CI) Pyridine-sulfur trioxide complex Pyridine-sulfur trioxide complex (1:1) Sulfur trioxide pyridine complex Sulfur trioxide, compd. with pyridine (1:1) Sulphur trioxide pyridine (1:1)