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稀土金属配合物由于具有优良的光磁性质和非对称催化能力,多年来受到了人们的普遍关注。文章以稀土β-二酮配合物[Ln(dbm)_3(H_2O)](dbm=1,3-二苯基-1,3-丙二酮,Ln=La~(3+),Nd~(3+),Eu~(3+),Sm~(3+)),[Yb(d-hfbc)_3(H_2O)]和[Yb(l-hfbc)_3(TPPO)_2](d/l-hfbc=3-七氟丁烯(+)/(-)樟脑,TPPO=氧化三苯基膦)为例,重点讨论了该类配合物ECD谱的理论解析。计算结果表明,理论ECD谱与实验谱吻合得很好,该类配合物在可见紫外区的ECD谱是由配体的π→π*激子耦合跃迁产生的,ECD谱中负手性的和正手性的激子裂分分别对应于Δ和Λ金属中心手性。这一结论对于深入理解稀土配合物绝对构型与手征光学性质之间的关系具有重要的科学意义。
Due to its excellent magneto-optical properties and asymmetric catalytic ability, rare-earth metal complexes have drawn people’s attention for many years. In this paper, the rare earth β-diketone complexes [Ln (dbm) _3 (H_2O)] (dbm = 1,3-diphenyl- 1,3-propanedione, Ln = La ~ (Yb (d-hfbc) _3 (H_2O)] and [Yb (l-hfbc) _3 (TPPO) _2] (d / l- hfbc = 3-heptafluorobutene (+) / (-) camphor, TPPO = triphenylphosphine oxide), the theoretical analysis of ECD spectra of these complexes was mainly discussed. The calculated results show that the theoretical ECD spectra are in good agreement with the experimental one. The ECD spectra of these complexes in the visible UV region are generated by the π → π * exciton coupling transition of the ligands. The negative and positive Chiral exciton splits correspond to Δ and Λ metal center chirality, respectively. This conclusion is of great scientific significance for understanding the relationship between the absolute configuration of rare earth complexes and the optical properties of chiral lenses.