Definitive assignments of the visible-near-IR bands of porphyrin-naphthalocyanine rare-earth sandwich double- and triple-decker compounds by magnetic circular dichroism spectroscopy.
Definitive assignments of the visible-near-IR bands of porphyrin-naphthalocyanine rare-earth sandwich double- and triple-decker compounds by magnetic circular dichroism spectroscopy.
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DOI：
10.1021/ic0502325
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发表时间：
2005-04
影响因子：
4.6
通讯作者：
A. Muranaka;Yotaro Matsumoto;M. Uchiyama;Jianzhuang Jiang;Yongzhong Bian;A. Ceulemans;N. Kobayashi
中科院分区：
文献类型：
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作者：
A. Muranaka;Yotaro Matsumoto;M. Uchiyama;Jianzhuang Jiang;Yongzhong Bian;A. Ceulemans;N. Kobayashi
利用电子吸收和磁圆二色（MCD）光谱研究了一系列稀土杂电夹层配合物[M(Nc)(OEP)] （M = La, Nd, Eu, Dy, Lu; Nc = 2,3-萘thalocyaninate； OEP = octaethylporphyrinate）。中性形式的电子吸收光谱在近红外区域显示出两个特征跃迁（波段I和波段II），这两个特征跃迁都取决于其中心金属的大小。在MCD光谱中，分别观测到相对较强的法拉第a项和较弱的法拉第B项对应于波段II和波段I。通过考虑组成发色团的四个古特曼轨道的相互作用，用简单的MO模型成功地解释了光谱特征。该模型成功地分配了相关化合物的MCD光谱，二聚体的氧化和还原形式([M(Nc)(OEP)]+和[M(Nc)(OEP)]-)，以及三层化合物的中性形式(M2（Nc)(OEP)2, M = Nd, Eu）。二聚体的DFT计算支持了该模型的有效性。
A series of heteroleptic rare-earth sandwich complexes [M(Nc)(OEP)] (M = La, Nd, Eu, Dy, and Lu; Nc = 2,3-naphthalocyaninate; OEP = octaethylporphyrinate) have been investigated by electronic absorption and magnetic circular dichroism (MCD) spectroscopy. The electronic absorption spectra of the neutral forms showed two characteristic transitions (bands I and II) in the near-IR region, both of which were systematically shifted depending on the size of their central metal. In the MCD spectra, a relatively intense Faraday A term and a significantly weak Faraday B term have been observed corresponding to bands II and I, respectively. The spectral features were successfully interpreted using a simple MO model by considering the relevant interactions of Gouterman's four orbitals of the constituent chromophores. The model succeeded in assigning the MCD spectra of the related compounds, the oxidized and reduced forms of the dimer ([M(Nc)(OEP)]+ and [M(Nc)(OEP)]-), and neutral forms of the triple-decker compounds (M2(Nc)(OEP)2, M = Nd, Eu). DFT calculations of the dimers supported the validity of this model.