Work

The Type D hyperporphyrin effect

Year: 2025

Type: article

Abstract: DFT and TDDFT calculations lend credence to the importance of a Type D resonance form for triply protonated 5,10,15-tris(4-aminophenyl)-20-(4-pyridyl)porphyrin (with all central nitrogens and the pyridine nitrogen protonated), in which all four meso-aryl groups engage in conjugative interactions with the porphyrin core. The LUMO of this species is strongly stabilized relative to the HOMO and LUMO+1 as a result of such an interaction with the pyridinium group, which leads to both a narrowing of the HOMO-LUMO gap and strongly split HOMO-to-LUMO and HOMO-to-LUMO+1 transitions in the Q region. This orbital energy pattern also explains key elements of the hyperporphyrin character of the species, strong redshifts of both the HOMO-to-LUMO transition in the Q region and the HOMO-1-to-LUMO transition in the Soret region.

Source: Journal of Porphyrins and Phthalocyanines

DOI: 10.1142/s1088424625500518

Authors: Carl C. Wamser, Jeanet Conradie, Abhik Ghosh

Institutions: Portland State University, University of the Free State, UiT The Arctic University of Norway

Language: English

Topic: Porphyrin and Phthalocyanine Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: Norges Forskningsråd

Award: G1636584653