Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China.
J Mol Graph Model. 2012 May;35:49-56. doi: 10.1016/j.jmgm.2011.12.011. Epub 2012 Feb 4.
The chiroptical properties of bisarylimidos bearing o-alkoxy chain-substituted polyoxomolybdates Mo(6)O(17)(2,2'-NC(6)H(4)OC(n)H(2n)OC(6)H(4)N) [n=4(2), 6(3±), 8(4)] were investigated using the time-dependent density functional method. The results showed that the studied chiral polyoxometalates (POMs) manifested similar absorption sites but displayed different shapes and magnitudes in their electronic circular dichroism (ECD) spectra. The ECD spectra of the studied chiral POMs originated from charge-transfer (CT) transitions from arylimido fragments to the POM cages and from oxygen atoms to the molybdenum atoms in the POM cages. The o-alkoxy chain served as a scaffold for generating chirality rather than contributing to the ECD spectrum of the studied POMs. The induced chiralities of the POM cages were defined by the CT transitions, which were completely localized on the POM cages. Furthermore, the long-range corrected CAM-B3LYP hybrid functional and a basis set that is larger than Lanl2DZ should be used for ECD calculations of chiral POMs. Our work establishes the use of computational studies to investigate the chiroptical properties of chiral POMs and provides theoretical interpretations.
用含邻位烷氧基取代的双芳酰亚胺多钼酸盐Mo(6)O(17)(2,2'-NC(6)H(4)OC(n)H(2n)OC(6)H(4)N) [n=4(2), 6(3±), 8(4)]作为模型，采用含时密度泛函理论方法研究了手性双芳酰亚胺多金属氧酸盐的旋光性质。结果表明，所研究的手性多金属氧酸盐（POMs）表现出相似的吸收位置，但在其电子圆二色性（ECD）谱中表现出不同的形状和大小。研究的手性 POMs 的 ECD 光谱源于芳酰亚胺片段到 POM 笼和氧原子到 POM 笼中钼原子的电荷转移（CT）跃迁。邻位烷氧基链作为产生手性的支架，而不是对所研究的 POM 的 ECD 光谱做出贡献。POM 笼的诱导手性由 CT 跃迁定义，该跃迁完全定域在 POM 笼上。此外，对于手性 POM 的 ECD 计算，应使用长程校正 CAM-B3LYP 杂化泛函和大于 Lanl2DZ 的基组。我们的工作建立了使用计算研究来研究手性 POM 的旋光性质，并提供了理论解释。
