An Evolved Explanation for the Molecular Geometry and Electronic Structure of Diphenyl-Substituted Cyclic Trimethylenemethane in the Ground State: A Nearly Planar Conformation with a Considerably Localized Electronic State
作者:Hiroshi Ikeda、Hayato Namai、Hirotsugu Taki、Tsutomu Miyashi
DOI:10.1021/jo047893o
日期:2005.5.1
using 11•• and 13•• support the conclusion based on the experiments and calculations. Therefore, we propose an evolved explanation for the molecular geometry and electronic structure of the ground state of 3•• in a low-temperature matrix, a nearly planar conformation with a considerably localized electronic state, which alone accounts for the spectroscopic characteristics.
我们重新研究了二苯基取代的五元环状三亚甲基甲烷(TMM)双自由基(Berson's TMM,3 ••)将UV / VIS吸收和发射光谱与密度泛函理论(DFT)和时变(TD)-DFT计算相结合。两个强的吸收带,A和B,与λ AB在298和328纳米,分别,弱吸收带C,与λ AB在472纳米,且强烈的发射带d,与λ EM在491处观察到对3 ••。通过比较3 ••与1,1-二苯乙基(7 •)和环戊-2-烯-1-基(9 •)自由基,发现带B,C和D源自二苯基甲基自由基部分(亚基I),而带A最有可能被分配给与亚基I和残基亚基II之间的相互作用有关的电子跃迁。环戊烯基基团部分。UB3LYP / cc-pVDZ计算表明,在基态下,3 ••尽管它们几乎是平面构型(θ= + 23.5°),但它们主要分别定位在亚基I和II中,它们之间的相互作用效率低下。此外,TD-UB3LYP / cc-pVDZ计算表明吸