Publication detail

Triplet Excited State Mechanistic Study of meso-Substituted Methylthio Bodipy Derivative: Time-Resolved Optical and Electron Paramagnetic Resonance Spectral Studies

Imran, M. Kurganskii, I. Taddei, M. Butera, V. Zhao, JZ. Fedin, MV. Di Donato, M. Mazzone, G.

Original Title

Triplet Excited State Mechanistic Study of meso-Substituted Methylthio Bodipy Derivative: Time-Resolved Optical and Electron Paramagnetic Resonance Spectral Studies

Type

journal article in Web of Science

Language

English

Original Abstract

Understanding the intersystem crossing (ISC) mechanism of organic compounds is essential for designing new triplet photosensitizers. Herein, we investigated the ISC mechanism of a heavy atom-free Bodipy derivative with thiomethyl substitution (S-BDP). A long-lived triplet state was observed with nanosecond transient absorption spectroscopy with lifetime of 7.5 ms in a polymer film and 178 mu s intrinsic lifetime in fluid solution, much longer as compared with what was previously reported (apparent triplet lifetime=15.5 mu s). Femtosecond transient absorption studies retrieved an ISC time constant of similar to 3 ns. Time-resolved electron paramagnetic resonance (TREPR) indicated a special triplet electron spin polarization phase (ESP) pattern (a, e, a, e, a, e) for S-BDP, different from the ESP (e, e, e, a, a, a) typical for the spin-orbital coupling (SOC) mechanism. This indicates that the electron spin selectivity of the ISC of S-BDP is different from that of the normal SOC effect in iodo-Bodipy. Simulations of the TREPR spectra give a zero-field-splitting D parameter of -2257 MHz, much smaller as compared to the reference 2,6-diiodo-Bodipy (D=-4380 MHz). The computed SOC matrix elements (0.28-1.59 cm(-1)) and energy gaps for the S-1/T-n states suggest that the energy matching between the S-1 and T-2/T-3 states (supported by the largest k(ISC) similar to 10(9) s(-1)) enhances the ISC for this compound.

Keywords

BODIPY; intersystem crossing; photosensitizers; time-resolved electron paramagnetic resonance; triplet states

Authors

Imran, M.; Kurganskii, I.; Taddei, M.; Butera, V.; Zhao, JZ.; Fedin, MV.; Di Donato, M.; Mazzone, G.

Released

1. 7. 2024

Publisher

WILEY-V C H VERLAG GMBH

Location

WEINHEIM

ISBN

2367-0932

Periodical

ChemPhotoChem

Year of study

8

Number

7

State

Federal Republic of Germany

Pages count

11

URL

https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cptc.202300320

BibTex

@article{BUT188752,
  author="Valeria {Butera} and Muhammad {Imran} and Ivan {Kurganskii} and Maria {Taddei} and Jianzhang {Zhao} and Matvey V. {Fedin} and Mariangela {Di Donato} and Gloria {Mazzone}",
  title="Triplet Excited State Mechanistic Study of meso-Substituted Methylthio Bodipy Derivative: Time-Resolved Optical and Electron Paramagnetic Resonance Spectral Studies",
  journal="ChemPhotoChem",
  year="2024",
  volume="8",
  number="7",
  pages="11",
  doi="10.1002/cptc.202300320",
  issn="2367-0932",
  url="https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cptc.202300320"
}