Understanding Anionic Hyperporphyrins: TDDFT Calculations on Peripherally Deprotonated <i>meso</i>-Tetrakis(4-hydroxyphenyl)porphyrin.

ABSTRACT: Presented herein is a DFT/TDDFT study of meso-tetrakis(4-hydroxyphenyl)porphyrin (H₂[THPP]) and its O-deprotonated tetraanionic form; the latter was modeled as both a free tetraanion and with various counterions. Based on our calculations, the experimentally observed hyperporphyrin spectra are attributed to an admixture of phenol/phenoxide character into the a_2u-type HOMO of tetraphenylporphyrin. The admixture results in an elevation of the orbital energy of the HOMO in relation to other frontier orbitals, which accounts for the observed spectral redshifts. The calculations underscore differences in the performance of different exchange-correlation functionals. Thus, while the popular hybrid functional B3LYP greatly exaggerates the redshift of the far-re

SUBMITTER: Conradie J 

PROVIDER: S-EPMC11831667 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature