Ultrafast intramolecular energy relaxation dynamics of benzoporphyrins: Influence of fused benzo rings on singlet excited states

Pyosang Kim, Jooyoung Sung, Hiroki Uoyama, Tetsuo Okujima, Hidemitsu Uno*, Dongho Kim

*Corresponding author for this work

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We have investigated the role of fused benzo rings on the electronic structures and intramolecular energy relaxation dynamics in a series of benzoporphyrins (Bp1, syn-Bp2, anti-Bp2, Bp3, and Bp4) by using time-resolved fluorescence measurements and theoretical calculations. Interestingly, even though anti- and syn-Bp2 have the same number of fused benzo rings, in the respective absorption spectra, anti-Bp2 shows an obvious splitting of B x (Qx) and By (Qy) states, whereas syn-Bp2 exhibits degenerate B and Q bands. These features provide two dynamical models for the effect of the position of substituted benzo rings on the intramolecular energy relaxation dynamics. syn-Bp2 gives rise to similar intramolecular dynamics from the B state to the Q state in the case of ZnTPP having D4h molecular symmetry. On the other hand, anti-Bp2 shows split B and Q bands in the order By > Bx > Q x > Qy, which leads a superimposition of the Q x (0,0) and Qy (1,0) bands. This overlap generates a strong coupling between these two states, which results in a direct internal conversion from Bx (0,0) to Qy (0,0). This observation suggests that the anti-type fused position of benzo rings leads to a new mechanism in internal conversion from the B to the Q state. On the basis of this work, further insight was obtained into the effect of fused benzo rings on the photophysical properties of benzoporphyrins, providing a detailed understanding of the structure-property relationship in a series of benzoporphyrins.

Original languageEnglish (US)
Pages (from-to)3784-3792
Number of pages9
JournalJournal of Physical Chemistry B
Volume115
Issue number14
DOIs
StatePublished - Apr 14 2011

Fingerprint

Excited states
Fluorescence
rings
excitation
internal conversion
Electronic structure
energy
Absorption spectra
electronic structure
absorption spectra
fluorescence
symmetry

ASJC Scopus subject areas

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

Cite this

Kim, Pyosang ; Sung, Jooyoung ; Uoyama, Hiroki ; Okujima, Tetsuo ; Uno, Hidemitsu ; Kim, Dongho. / Ultrafast intramolecular energy relaxation dynamics of benzoporphyrins : Influence of fused benzo rings on singlet excited states. In: Journal of Physical Chemistry B. 2011 ; Vol. 115, No. 14. pp. 3784-3792.
@article{74496d84bcd141bf9af04547de97f71c,
title = "Ultrafast intramolecular energy relaxation dynamics of benzoporphyrins: Influence of fused benzo rings on singlet excited states",
abstract = "We have investigated the role of fused benzo rings on the electronic structures and intramolecular energy relaxation dynamics in a series of benzoporphyrins (Bp1, syn-Bp2, anti-Bp2, Bp3, and Bp4) by using time-resolved fluorescence measurements and theoretical calculations. Interestingly, even though anti- and syn-Bp2 have the same number of fused benzo rings, in the respective absorption spectra, anti-Bp2 shows an obvious splitting of B x (Qx) and By (Qy) states, whereas syn-Bp2 exhibits degenerate B and Q bands. These features provide two dynamical models for the effect of the position of substituted benzo rings on the intramolecular energy relaxation dynamics. syn-Bp2 gives rise to similar intramolecular dynamics from the B state to the Q state in the case of ZnTPP having D4h molecular symmetry. On the other hand, anti-Bp2 shows split B and Q bands in the order By > Bx > Q x > Qy, which leads a superimposition of the Q x (0,0) and Qy (1,0) bands. This overlap generates a strong coupling between these two states, which results in a direct internal conversion from Bx (0,0) to Qy (0,0). This observation suggests that the anti-type fused position of benzo rings leads to a new mechanism in internal conversion from the B to the Q state. On the basis of this work, further insight was obtained into the effect of fused benzo rings on the photophysical properties of benzoporphyrins, providing a detailed understanding of the structure-property relationship in a series of benzoporphyrins.",
author = "Pyosang Kim and Jooyoung Sung and Hiroki Uoyama and Tetsuo Okujima and Hidemitsu Uno and Dongho Kim",
year = "2011",
month = "4",
day = "14",
doi = "10.1021/jp200493p",
language = "English (US)",
volume = "115",
pages = "3784--3792",
journal = "Journal of Physical Chemistry B",
issn = "1520-6106",
number = "14",

}

Ultrafast intramolecular energy relaxation dynamics of benzoporphyrins : Influence of fused benzo rings on singlet excited states. / Kim, Pyosang; Sung, Jooyoung; Uoyama, Hiroki; Okujima, Tetsuo; Uno, Hidemitsu; Kim, Dongho.

In: Journal of Physical Chemistry B, Vol. 115, No. 14, 14.04.2011, p. 3784-3792.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ultrafast intramolecular energy relaxation dynamics of benzoporphyrins

T2 - Influence of fused benzo rings on singlet excited states

AU - Kim, Pyosang

AU - Sung, Jooyoung

AU - Uoyama, Hiroki

AU - Okujima, Tetsuo

AU - Uno, Hidemitsu

AU - Kim, Dongho

PY - 2011/4/14

Y1 - 2011/4/14

N2 - We have investigated the role of fused benzo rings on the electronic structures and intramolecular energy relaxation dynamics in a series of benzoporphyrins (Bp1, syn-Bp2, anti-Bp2, Bp3, and Bp4) by using time-resolved fluorescence measurements and theoretical calculations. Interestingly, even though anti- and syn-Bp2 have the same number of fused benzo rings, in the respective absorption spectra, anti-Bp2 shows an obvious splitting of B x (Qx) and By (Qy) states, whereas syn-Bp2 exhibits degenerate B and Q bands. These features provide two dynamical models for the effect of the position of substituted benzo rings on the intramolecular energy relaxation dynamics. syn-Bp2 gives rise to similar intramolecular dynamics from the B state to the Q state in the case of ZnTPP having D4h molecular symmetry. On the other hand, anti-Bp2 shows split B and Q bands in the order By > Bx > Q x > Qy, which leads a superimposition of the Q x (0,0) and Qy (1,0) bands. This overlap generates a strong coupling between these two states, which results in a direct internal conversion from Bx (0,0) to Qy (0,0). This observation suggests that the anti-type fused position of benzo rings leads to a new mechanism in internal conversion from the B to the Q state. On the basis of this work, further insight was obtained into the effect of fused benzo rings on the photophysical properties of benzoporphyrins, providing a detailed understanding of the structure-property relationship in a series of benzoporphyrins.

AB - We have investigated the role of fused benzo rings on the electronic structures and intramolecular energy relaxation dynamics in a series of benzoporphyrins (Bp1, syn-Bp2, anti-Bp2, Bp3, and Bp4) by using time-resolved fluorescence measurements and theoretical calculations. Interestingly, even though anti- and syn-Bp2 have the same number of fused benzo rings, in the respective absorption spectra, anti-Bp2 shows an obvious splitting of B x (Qx) and By (Qy) states, whereas syn-Bp2 exhibits degenerate B and Q bands. These features provide two dynamical models for the effect of the position of substituted benzo rings on the intramolecular energy relaxation dynamics. syn-Bp2 gives rise to similar intramolecular dynamics from the B state to the Q state in the case of ZnTPP having D4h molecular symmetry. On the other hand, anti-Bp2 shows split B and Q bands in the order By > Bx > Q x > Qy, which leads a superimposition of the Q x (0,0) and Qy (1,0) bands. This overlap generates a strong coupling between these two states, which results in a direct internal conversion from Bx (0,0) to Qy (0,0). This observation suggests that the anti-type fused position of benzo rings leads to a new mechanism in internal conversion from the B to the Q state. On the basis of this work, further insight was obtained into the effect of fused benzo rings on the photophysical properties of benzoporphyrins, providing a detailed understanding of the structure-property relationship in a series of benzoporphyrins.

UR - http://www.scopus.com/inward/record.url?scp=79953771292&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79953771292&partnerID=8YFLogxK

U2 - 10.1021/jp200493p

DO - 10.1021/jp200493p

M3 - Article

C2 - 21425822

AN - SCOPUS:79953771292

VL - 115

SP - 3784

EP - 3792

JO - Journal of Physical Chemistry B

JF - Journal of Physical Chemistry B

SN - 1520-6106

IS - 14

ER -