Work

Database of low‐temperature absorption and fluorescence spectra of native photosynthetic tetrapyrrole macrocycles

Year: 2025

Type: article

Abstract: Low‐temperature (77 K) absorption and fluorescence spectra of 12 naturally occurring photosynthetic tetrapyrrole macrocycles have been recorded in a frozen glass (2‐methyltetrahydrofuran). The compounds encompass distinct chromophore classes: porphyrin, chlorophyll c 2 ; chlorin, chlorophylls a , b , d , f and bacteriochlorophylls c , d , e , f ; and bacteriochlorin, bacteriochlorophylls a , b , g . The spectra are compared with those of the same pigment in liquid solution (predominantly 2‐methyltetrahydrofuran) at room temperature (293 K). The measured Stokes shifts at 77 K across the 12 macrocycles range from ~30 to 300 cm −1 . The spectral data in digital form are made available as part of the PhotochemCAD databases. Literature searches have revealed extensive published data for Chl a (often in biological matrices) but at best rather limited data for less common macrocycles. The availability of a systematic collection of curated spectral data collected at low temperature should be useful for a variety of assessments, including reconstruction of absorption spectra of (bacterio)chlorophyll‐containing protein complexes, vibrational analysis of absorption and fluorescence spectra, and calculations where knowledge of energy levels is important.

Source: Photochemistry and Photobiology

DOI: 10.1111/php.70018

Authors: Dariusz M. Niedzwiedzki, Masahiko Taniguchi, Jonathan S. Lindsey

Institutions: Washington University in St. Louis, North Carolina State University

Language: English

Topic: Porphyrin and Phthalocyanine Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,330

Funders: U.S. Department of Energy, Saint Louis University, Basic Energy Sciences