Electronic Structure of<b><i>N</i></b>,<b><i>N</i></b>′-Bis(2-aminobenzylidene)ethylenediaminatocopper(II)
作者:Ken-ichi Kumagai、Miki Hasegawa、Shigendo Enomoto、Toshihiko Hoshi
DOI:10.1246/bcsj.74.441
日期:2001.3
The electronic absorption spectra of N,N′-bis(2-aminobenzylidene)ethylenediaminatocopper(II) (abbreviated to [Cu(amben)]) were measured in ethanol and in a KBr disk. From these spectral data together with the polarization spectrum in a stretched PVA film, the X-ray photoelectron spectra, and a VESCF-MO-CI calculation, the electronic structure of [Cu(amben)] has been clarified. The reduced polarization spectrum shows that [Cu(amben)] has longer-molecular axis (y) polarized bands at 438, 300, 280, 257.7 and 222 nm, and shorter ones (z) at 418, 280, 260, 242.5 and 224 nm. The 300 nm band is assigned to an overlap of the calculated ππ*3 and ππ*4 transitions, which are charge transfer transitions between the two π-electronic systems localized almost independently on the 2-aminobenzylideneimino groups. The solid-state electronic absorption bands, measured in a KBr disk, of [Cu(amben)] are red-shifted by 2-16 nm, and considerably broadened compared with those in ethanol, indicating that the [Cu(amben)] molecules interact significantly in the solid state. The mechanism of the intermolecular interactions is discussed using the concept of the exciton model. XPS measurements show that the degree of the charge transfer from the ligand to the metal ion in [Cu(amben)] is less than that in N,N′-disalicylideneethylenediaminatocopper(II) in the ground state.
在乙醇和 KBr 盘中测量 N,N'-双(2-氨基亚苄基)乙二胺铜(II)(缩写为 [Cu(amben)])的电子吸收光谱。根据这些光谱数据以及拉伸 PVA 薄膜中的偏振光谱、X 射线光电子能谱和 VECF-MO-CI 计算,[Cu(amben)] 的电子结构已得到阐明。约化偏振光谱显示[Cu(amben)]在438、300、280、257.7和222 nm处具有较长分子轴(y)偏振带,在418、280、260、242.5和224 nm处具有较短分子轴(z)偏振带。纳米。 300 nm 波段被分配给计算出的 ππ*3 和 ππ*4 跃迁的重叠,这是两个几乎独立位于 2-氨基苯亚甲基亚氨基上的 π 电子系统之间的电荷转移跃迁。在 KBr 盘中测量,[Cu(amben)] 的固态电子吸收带红移 2-16 nm,并且与乙醇中的相比显着变宽,表明 [Cu(amben)] 分子在固态下相互作用显着。使用激子模型的概念讨论了分子间相互作用的机制。 XPS测量表明,[Cu(amben)]中从配体到金属离子的电荷转移程度小于基态N,N'-二水杨基亚乙基二氨基铜(II)中的电荷转移程度。