Fundamental electronic changes upon intersystem crossing in large aromatic photosensitizers: free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin

Free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin stands for the class of powerful porphyrin photosensitizers for singlet oxygen generation and light-harvesting. The atomic level selectivity of dynamic UV pump - N K-edge probe X-ray absorption spectroscopy in combination with time-dependent density functional theory (TD-DFT) gives direct access to the crucial excited molecular states within the unusual relaxation pathway. The efficient intersystem crossing, that is El-Sayed forbidden and not facilitated by a heavy atom is confirmed to be the result of the long singlet excited state lifetime (Q(x) 4.9 ns) and thermal effects. Overall, the interplay of stabilization by conservation of angular momenta and vibronic relaxation drive the de-excitation in these chromophores.

Metadaten
Author details:	Robby Büchner ORCiD GND, Vinicius Vaz da Cruz ORCiD, Nitika Grover ORCiD, Asterios Charisiadis ORCiD, Mattis Fondell ORCiD, Robert Haverkamp ORCiD, Mathias O. Senge ORCiD GND, Alexander Föhlisch ORCiD GND
DOI:	https://doi.org/10.1039/d1cp05420a
ISSN:	1463-9076
ISSN:	1463-9084
Pubmed ID:	https://pubmed.ncbi.nlm.nih.gov/35288726
Title of parent work (English):	Physical chemistry, chemical physics : a journal of European Chemical Societies
Publisher:	Royal Society of Chemistry
Place of publishing:	Cambridge
Publication type:	Article
Language:	English
Date of first publication:	2022/03/15
Publication year:	2022
Release date:	2024/05/24
Volume:	24
Issue:	12
Number of pages:	7
First page:	7505
Last Page:	7511
Funding institution:	ERC-ADG-2014 - Advanced Investigator Grant under the Horizon 2020 EU; Framework Program for Research and Innovation [669531 EDAX]; Higher; Education Authority; Department of Further and Higher Education,; Research, Innovation and Science (Ireland); Technical University of; Munich - Institute for Advanced Study through a Hans Fischer Senior; Fellowship
Organizational units:	Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie
Peer review:	Referiert
Publishing method:	Open Access / Hybrid Open-Access