The absorption spectra of H2[THPP] and its O-deprotonated hyperporphyrin form {H2[TOPP]} 4-have been reported in several different studies. Several of these studies also describe the hyperporphyrin generated by protonation of H2[THPP], a hyperporphyrin analogous to that from protonation of H2 [TAPP]. Briefly, the spectrum of H2[THPP] is that of a normal porphyrin with a strong Soret (B) band and four Q bands that fit the Gouterman four-orbital model, while the spectrum of {H4[THPP]} 2+ is that of a mild hyperporphyrin. In a comprehensive study of a series of para-substituted tetraphenylporphyrins (TPPs), H2[THPP] shows a distinctive hyperporphyrin redshift upon protonation, unlike TPPs with electron-withdrawing substituents, but not as large as stronger electron-donating substituents such as amino or dimethylamino. Depending on solvent, the lowest energy Q band of H2[THPP] shifts from 660 nm to about 700 nm upon protonation. For comparison, the data for H2[TAPP] are 669 nm and 813 nm; in addition, the far-red hyperporphyrin band for {H4[TAPP]} 2+ is much stronger than that of {H4[THPP]} 2+ .