.alpha.,.beta.,.gamma.,.delta.-Tetraphenylporphine 21H,23H-Porphine, 5,10,15,20-tetraphenyl- 5,10,15,20-Tetraphenylporphine 917-23-7 NSC18506 Porphine, 5,10,15,20-tetraphenyl- Tetraphenylporphine Tetraphenylporphyrin meso-Tetraphenylporphine meso-Tetraphenylporphyrin