Tachikawa Hiroto, Kawabata Hiroshi, Miyamoto Ryoji, Nakayama Ken-Ichi, Yokoyama Masaaki
Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
J Phys Chem B. 2005 Mar 3;109(8):3139-45. doi: 10.1021/jp046168e.
Electronic absorption, Fourier transform-infrared (FT-IR), and electron spin resonance spectra of aluminum-naphthalene tetracarboxylic dianhydlide (Al-NTCDA) co-deposited film have been measured at room temperature, and hybrid density functional theory (DFT) calculations have been carried out in order to elucidate the electronic states for the ground and low-lying excited states of the complexes. After the interaction of NTCDA with Al atom, the new electronic transition bands were appeared at near-IR region. The C=O stretching modes of NTCDA are red-shifted by the interaction with Al. From the DFT calculations, it was found that the electronic state of the complex at the ground state is characterized by a slight charge-transfer state expressed by (Al(4))(delta+)(NTCDA)(delta-). The binding of Al to NTCDA is strong. The C=O double-bond character of NTCDA is changed to C-O single-bond-like character by the strong interaction of Al to the C=O bond. This is the origin of the red-shift of the FT-IR spectrum. The electronic states of organic-inorganic hybrid material were discussed on the basis of theoretical results.
在室温下测量了铝-萘四羧酸二酐（Al-NTCDA）共沉积膜的电子吸收光谱、傅里叶变换红外（FT-IR）光谱和电子自旋共振光谱，并进行了杂化密度泛函理论（DFT）计算，以阐明配合物基态和低激发态的电子态。NTCDA与Al原子相互作用后，在近红外区域出现了新的电子跃迁带。NTCDA的C=O伸缩振动模式因与Al的相互作用而发生红移。从DFT计算结果发现，配合物基态的电子态以轻微的电荷转移态为特征，可表示为(Al(4))(δ+)(NTCDA)(δ-)。Al与NTCDA的结合很强。由于Al与C=O键的强相互作用，NTCDA的C=O双键性质转变为类似C-O单键的性质。这就是FT-IR光谱红移的原因。基于理论结果讨论了有机-无机杂化材料的电子态。
