TY - JOUR
T1 - Effect of periodic replacement of the heteroatom on the spectroscopic properties of indole and benzofuran derivatives
AU - Muranaka, Atsuya
AU - Yasuike, Shuji
AU - Liu, Ching Yuan
AU - Kurita, Jyoji
AU - Kakusawa, Naoki
AU - Tsuchiya, Takashi
AU - Okuda, Masako
AU - Kobayashi, Nagao
AU - Matsumoto, Yotaro
AU - Yoshida, Kengo
AU - Hashizume, Daisuke
AU - Uchiyama, Masanobu
PY - 2009/1/15
Y1 - 2009/1/15
N2 - The electronic structures of a homologous series of indole and benzofuran derivatives, in which the nitrogen or oxygen atom is replaced by group 15 and group 16 heavier heteroatoms, have been investigated by means of various spectroscopic techniques coupled with density functional calculations. It was found that the excitation energies of the group 16 benzoheteroles systematically shift to the red in the order of benzofuran (6), benzothiophene (7), benzoselenophene (8), and benzotellurophene (9). In contrast, the electronic absorption spectra of the group 15 benzoheteroles, 1-phenyl derivatives of indole (1b), phosphindole (2b), arsindole (3b), stibindole (4b), and bismuindole (5b), did not exhibit this type of spectral shift. X-ray analysis and density functional theory (DFT) studies revealed that 2b-5b adopt a bent conformation both in the crystalline and in the solution phases. In contrast, planar structures were calculated for the group 16 heterocycles. Using the observed spectroscopic properties and time-dependent density functional theory (TDDFT) calculations, the electronic absorption spectra of the present heterocycles were assigned. A molecular orbital analysis was performed to rationalize the effect of replacement of the heteroatom on the electronic structures. The observed magnetic circular dichroism (MCD) sign patterns of these heterocycles are interpreted according to Michl's perimeter model.
AB - The electronic structures of a homologous series of indole and benzofuran derivatives, in which the nitrogen or oxygen atom is replaced by group 15 and group 16 heavier heteroatoms, have been investigated by means of various spectroscopic techniques coupled with density functional calculations. It was found that the excitation energies of the group 16 benzoheteroles systematically shift to the red in the order of benzofuran (6), benzothiophene (7), benzoselenophene (8), and benzotellurophene (9). In contrast, the electronic absorption spectra of the group 15 benzoheteroles, 1-phenyl derivatives of indole (1b), phosphindole (2b), arsindole (3b), stibindole (4b), and bismuindole (5b), did not exhibit this type of spectral shift. X-ray analysis and density functional theory (DFT) studies revealed that 2b-5b adopt a bent conformation both in the crystalline and in the solution phases. In contrast, planar structures were calculated for the group 16 heterocycles. Using the observed spectroscopic properties and time-dependent density functional theory (TDDFT) calculations, the electronic absorption spectra of the present heterocycles were assigned. A molecular orbital analysis was performed to rationalize the effect of replacement of the heteroatom on the electronic structures. The observed magnetic circular dichroism (MCD) sign patterns of these heterocycles are interpreted according to Michl's perimeter model.
UR - http://www.scopus.com/inward/record.url?scp=61749097372&partnerID=8YFLogxK
U2 - 10.1021/jp8079843
DO - 10.1021/jp8079843
M3 - 期刊論文
C2 - 19099440
AN - SCOPUS:61749097372
VL - 113
SP - 464
EP - 473
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 2
ER -