Pyrrolo 3 4-f isoindole-1 3 5 7(2h 6h)-tetraone July 8, 2019 16 32 64 128 2-(3h- 1 2 3 triazolo 4 5-b pyridin-3-yl)-1 1 3 3-tetramethyluronium hexafluorophosphate(v)