Abstract
Self-assembled monolayers (SAMs) of porphyrins have been prepared to examine the substituent effects of porphyrin monolayers on the structure and photoelectrochemical properties of the SAMs on an ITO electrode. The ultraviolet (UV)-visible absorption, steady-state fluorescence, and cyclic voltammetry measurements for the porphyrin SAMs revealed that the interaction between the porphyrins without bulky tert-butyl groups is much larger than that of the porphyrins with bulky tert-butyl groups. Photoelectrochemical measurements were performed in nitrogen-saturated Na2SO4 aqueous solution containing triethanolamine as an electron sacrificer using the modified ITO working electrode, a platinum wire counter electrode, and an Ag/AgCl reference electrode. The internal quantum yields of photocurrent generation together with the porphyrin fluorescence lifetimes remain virtually the same irrespective of the steric hindrance, which is in sharp contrast with severe self-quenching of the porphyrin excited singlet state in conventional molecular assemblies such as Langmuir-Blodgett films. The two-dimensional, densely packed structure of the porphyrins in SAM is responsible for the long-lived excited singlet state, which is similar to the antenna function of photosystem I in cyanobacteria. These results will provide valuable information on the construction of artificial light-harvesting systems.
| Original language | English |
|---|---|
| Pages (from-to) | 5018-5025 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry B |
| Volume | 108 |
| Issue number | 16 |
| Publication status | Published - 2004 Apr 22 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry
Cite this
}
Substituent Effects of Porphyrin Monolayers on the Structure and Photoelectrochemical Properties of Self-Assembled Monolayers of Porphyrin on Indium-Tin Oxide Electrode. / Imahori, Hiroshi; Hosomizu, Kohei; Mori, Yukie; Sato, Tomoo; Ahn, Tae Kyu; Kim, Seong Keun; Kim, Dongho; Nishimura, Yoshinobu; Yamazaki, Iwao; Ishii, Hirotake; Hotta, Hiroki; Matano, Yoshihiro.
In: Journal of Physical Chemistry B, Vol. 108, No. 16, 22.04.2004, p. 5018-5025.Research output: Contribution to journal › Article
TY - JOUR
T1 - Substituent Effects of Porphyrin Monolayers on the Structure and Photoelectrochemical Properties of Self-Assembled Monolayers of Porphyrin on Indium-Tin Oxide Electrode
AU - Imahori, Hiroshi
AU - Hosomizu, Kohei
AU - Mori, Yukie
AU - Sato, Tomoo
AU - Ahn, Tae Kyu
AU - Kim, Seong Keun
AU - Kim, Dongho
AU - Nishimura, Yoshinobu
AU - Yamazaki, Iwao
AU - Ishii, Hirotake
AU - Hotta, Hiroki
AU - Matano, Yoshihiro
PY - 2004/4/22
Y1 - 2004/4/22
N2 - Self-assembled monolayers (SAMs) of porphyrins have been prepared to examine the substituent effects of porphyrin monolayers on the structure and photoelectrochemical properties of the SAMs on an ITO electrode. The ultraviolet (UV)-visible absorption, steady-state fluorescence, and cyclic voltammetry measurements for the porphyrin SAMs revealed that the interaction between the porphyrins without bulky tert-butyl groups is much larger than that of the porphyrins with bulky tert-butyl groups. Photoelectrochemical measurements were performed in nitrogen-saturated Na2SO4 aqueous solution containing triethanolamine as an electron sacrificer using the modified ITO working electrode, a platinum wire counter electrode, and an Ag/AgCl reference electrode. The internal quantum yields of photocurrent generation together with the porphyrin fluorescence lifetimes remain virtually the same irrespective of the steric hindrance, which is in sharp contrast with severe self-quenching of the porphyrin excited singlet state in conventional molecular assemblies such as Langmuir-Blodgett films. The two-dimensional, densely packed structure of the porphyrins in SAM is responsible for the long-lived excited singlet state, which is similar to the antenna function of photosystem I in cyanobacteria. These results will provide valuable information on the construction of artificial light-harvesting systems.
AB - Self-assembled monolayers (SAMs) of porphyrins have been prepared to examine the substituent effects of porphyrin monolayers on the structure and photoelectrochemical properties of the SAMs on an ITO electrode. The ultraviolet (UV)-visible absorption, steady-state fluorescence, and cyclic voltammetry measurements for the porphyrin SAMs revealed that the interaction between the porphyrins without bulky tert-butyl groups is much larger than that of the porphyrins with bulky tert-butyl groups. Photoelectrochemical measurements were performed in nitrogen-saturated Na2SO4 aqueous solution containing triethanolamine as an electron sacrificer using the modified ITO working electrode, a platinum wire counter electrode, and an Ag/AgCl reference electrode. The internal quantum yields of photocurrent generation together with the porphyrin fluorescence lifetimes remain virtually the same irrespective of the steric hindrance, which is in sharp contrast with severe self-quenching of the porphyrin excited singlet state in conventional molecular assemblies such as Langmuir-Blodgett films. The two-dimensional, densely packed structure of the porphyrins in SAM is responsible for the long-lived excited singlet state, which is similar to the antenna function of photosystem I in cyanobacteria. These results will provide valuable information on the construction of artificial light-harvesting systems.
UR - http://www.scopus.com/inward/record.url?scp=2342637755&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2342637755&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:2342637755
VL - 108
SP - 5018
EP - 5025
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 16
ER -