TY - JOUR
T1 - Highly pure synthesis, spectral assignments, and two-photon properties of cruciform porphyrin pentamers fused with benzene units
AU - Uoyama, Hiroki
AU - Kim, Kil Suk
AU - Kuroki, Kenji
AU - Shin, Jae Yoon
AU - Nagata, Toshi
AU - Okujima, Tetsuo
AU - Yamada, Hiroko
AU - Ono, Noboru
AU - Kim, Dongho
AU - Uno, Hidemitsu
PY - 2010/4/6
Y1 - 2010/4/6
N2 - Tetrameric porphyrin formation of 2-hydroxymethylpyrrole fused with porphyrins through a bicyclo[2.2.2]octadiene unit gave bicyclo[2.2.2]octadiene- fused porphyrin pentamers. Thermal conversion of the pentamers gave fully π-conjugated cruciform porphyrin pentamers fused with benzene units in quantitative yields. UV/Vis spectra of fully π-conjugated porphyrin pentamers showed one very strong Q absorption and were quite different from those of usual porphyr-ins. From TD-DFT calculations, the HOMO level is 0.49 eV higher than the HOMO-1 level. The LUMO and LUMO+ 1 levels are very close and are lower by more than 0.27 eV than those of other unoccupied MOs. The strong Q absorption was interpreted as two mutually orthogonal single-electron transitions (683 nm: 86%, HOMO LUMO; 680 nm: 86%, HOMO->LUMO + 1). The two-photon absorption (TPA) cross section value (σ(2)) of the benzene-fused porphyrin pentamer was estimated to be 3900 GM at 1500 nm, which is strongly correlated with a cruciform molecular structure with multidirectional π-conjugation pathways.
AB - Tetrameric porphyrin formation of 2-hydroxymethylpyrrole fused with porphyrins through a bicyclo[2.2.2]octadiene unit gave bicyclo[2.2.2]octadiene- fused porphyrin pentamers. Thermal conversion of the pentamers gave fully π-conjugated cruciform porphyrin pentamers fused with benzene units in quantitative yields. UV/Vis spectra of fully π-conjugated porphyrin pentamers showed one very strong Q absorption and were quite different from those of usual porphyr-ins. From TD-DFT calculations, the HOMO level is 0.49 eV higher than the HOMO-1 level. The LUMO and LUMO+ 1 levels are very close and are lower by more than 0.27 eV than those of other unoccupied MOs. The strong Q absorption was interpreted as two mutually orthogonal single-electron transitions (683 nm: 86%, HOMO LUMO; 680 nm: 86%, HOMO->LUMO + 1). The two-photon absorption (TPA) cross section value (σ(2)) of the benzene-fused porphyrin pentamer was estimated to be 3900 GM at 1500 nm, which is strongly correlated with a cruciform molecular structure with multidirectional π-conjugation pathways.
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U2 - 10.1002/chem.200903196
DO - 10.1002/chem.200903196
M3 - Article
C2 - 20175163
AN - SCOPUS:77950229229
VL - 16
SP - 4063
EP - 4074
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 13
ER -