Magnetic circular dichroism study of directly fused porphyrins.
Magnetic circular dichroism study of directly fused porphyrins.
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DOI：
10.1002/cphc.200400378
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发表时间：
2005-01
期刊：
影响因子：
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通讯作者：
A. Muranaka;M. Yokoyama;Yotaro Matsumoto;M. Uchiyama;Akihiko Tsuda;A. Osuka;N. Kobayashi
中科院分区：
文献类型：
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作者：
A. Muranaka;M. Yokoyama;Yotaro Matsumoto;M. Uchiyama;Akihiko Tsuda;A. Osuka;N. Kobayashi
本文测量了双链和三链稠合双卟啉（2 MD和2 MT，M = Ni，Zn，Cu，Pd和H_2）和三链高聚物（3 ZnT和4 ZnT）的磁性圆二色光谱，并根据INDO/s计算结果对它们的Q带进行了归属。与Ni（II）四苯基卟啉的Q（0，0）带的法拉第A项不同，在最低能量跃迁处观察到一个正的法拉第B项.计算结果表明，直接稠合卟啉的分子轨道（MO）由单体MO的线性组合组成，降低对称性对最低未占分子轨道（LUMO）的影响总是大于对最高已占分子轨道（HOMO）的影响. Michl的周长模型的基础上，这些功能可以与所观察到的积极MCD迹象在近红外区域。在600-700 nm处的弱吸收带可归属于短轴偏振Q跃迁。
The magnetic circular dichroism (MCD) spectra of doubly and triply linked fused bisporphyrins (2MD and 2MT, M = Ni, Zn, Cu, Pd, and H2) and triply linked higher oligomers (3ZnT and 4ZnT) have been measured, and their Q-bands assigned based on the results of INDO/s calculations. In contrast to the Faraday A term observed for the Q(0,0) band of Ni(II) tetraphenylporphyrin, a single positive Faraday B term was observed for the lowest energy transition of the fused systems. The calculations indicated that the molecular orbitals (MOs) of the directly fused porphyrins consist of linear combinations of the constituent monomeric MOs, and that the effect of lowering the symmetry is always larger on the lowest unoccupied molecular orbital (LUMO) than on the highest occupied molecular orbital (HOMO). On the basis of Michl's perimeter model, these features can be correlated with the observed positive MCD signs in the near infrared region. A weak absorption band at 600-700 nm for the fused dimers can be assigned to a short-axis polarized Q transition.