Photophysical properties of core-modified expanded porphyrins: Nature of aromaticky and enhancement of ring planarity

Min Chul Yoon, Rajneesh Misra, Zin Seok Yoon, Kil Suk Kim, Jong Min Lim, Tavarekere K. Chandrashekar, Dongho Kim

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

We have investigated the excited-state dynamics and nonlinear optical properties of representative coremodified expanded porphyrins, tetrathiarubyrin, tetraselenarubyrin, pentathiaheptaphyrin, tetrathiaoctaphyrin, and tetraselenaoctaphyrin, containing 26, 30, and 34 π electrons using steady-state and time-resolved absorption and fluorescence spectroscopic measurements along with femtosecond Z-scan method, with a particular attention to the photophysical properties related to molecular planarity and aromaticity. Core-modification of macrocycles by sulfur and selenium leads to NIR-extended steady-state absorption and fluorescence spectra and shortlived excited-state due to the heavy-atom effect in time-resolved spectroscopic experiments. Large negative nucleus-independent chemical shift values ranging from -13 to -15 ppm indicate that all molecular systems are highly aromatic. The observed enhancement of two-photon absorption cross-section values over 104 GM for core-modified hepta- and octaphyrins is mainly attributable to their rigid and planar structures as well as their aromaticity. Overall, the observed spectroscopic and theoretical results consistently demonstrate the enhanced molecular planarity of core-modified expanded porphyrins compared with their corresponding allaza expanded porphyrins.

Original languageEnglish
Pages (from-to)6900-6905
Number of pages6
JournalJournal of Physical Chemistry B
Volume112
Issue number23
DOIs
Publication statusPublished - 2008 Jun 12

Fingerprint

Porphyrins
porphyrins
Excited states
augmentation
rings
Fluorescence
fluorescence
planar structures
Selenium
Chemical shift
rigid structures
selenium
Sulfur
absorption cross sections
excitation
chemical equilibrium
sulfur
Photons
Optical properties
absorption spectra

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

Yoon, Min Chul ; Misra, Rajneesh ; Yoon, Zin Seok ; Kim, Kil Suk ; Lim, Jong Min ; Chandrashekar, Tavarekere K. ; Kim, Dongho. / Photophysical properties of core-modified expanded porphyrins : Nature of aromaticky and enhancement of ring planarity. In: Journal of Physical Chemistry B. 2008 ; Vol. 112, No. 23. pp. 6900-6905.
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Photophysical properties of core-modified expanded porphyrins : Nature of aromaticky and enhancement of ring planarity. / Yoon, Min Chul; Misra, Rajneesh; Yoon, Zin Seok; Kim, Kil Suk; Lim, Jong Min; Chandrashekar, Tavarekere K.; Kim, Dongho.

In: Journal of Physical Chemistry B, Vol. 112, No. 23, 12.06.2008, p. 6900-6905.

Research output: Contribution to journalArticle

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T2 - Nature of aromaticky and enhancement of ring planarity

AU - Yoon, Min Chul

AU - Misra, Rajneesh

AU - Yoon, Zin Seok

AU - Kim, Kil Suk

AU - Lim, Jong Min

AU - Chandrashekar, Tavarekere K.

AU - Kim, Dongho

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