Effect of the iodine atom position on the phosphorescence of BODIPY derivatives: a combined computational and experimental study

Photochem Photobiol Sci. 2022 May;21(5):777-786. doi: 10.1007/s43630-021-00152-5. Epub 2022 Jan 13.

Abstract

A new BODIPY derivative (o-I-BDP) containing an iodine atom in the ortho position of the meso-linked phenyl group was prepared. Photophysical and electrochemical properties of the molecule were compared to previously reported iodo BODIPY derivatives, as well as to the non-iodinated analog. While in the case of derivatives featuring iodine substituents in the BODIPY core, efficient population of the triplet state is accompanied by a substantial positive shift of the reduction potential compared to pristine BODIPY, o-I-BDP displays phosphorescence and simultaneously maintains the electrochemical properties of unsubstituted BODIPYs. A theoretical investigation was settled to analyze results and rationalize the influence of iodine position on electronic and photophysical properties, with the purpose of preparing a fully organic phosphorescent BODIPY derivative. TD-DFT and spin-orbit coupling calculations shed light on the subtle effects played by the introduction of iodine atom in different positions of BODIPY.

Keywords: DFT calculations; Phosphorescence; Singlet oxygen; Spin–orbit coupling calculations; Triplet state.

MeSH terms

  • Boron Compounds / chemistry
  • Density Functional Theory
  • Iodides
  • Iodine*
  • Photosensitizing Agents* / chemistry

Substances

  • 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
  • Boron Compounds
  • Iodides
  • Photosensitizing Agents
  • Iodine