Olsen Stine T, Elm Jonas, Storm Freja Eilsø, Gejl Aske Nørskov, Hansen Anne S, Hansen Mia Harring, Nikolajsen Jens Rix, Nielsen Mogens Brøndsted, Kjaergaard Henrik G, Mikkelsen Kurt V
Department of Chemistry, H. C. Ørsted Institute, University of Copenhagen , Universitetsparken 5, DK-2100 Copenhagen, Denmark.
J Phys Chem A. 2015 Feb 5;119(5):896-904. doi: 10.1021/jp510678u. Epub 2015 Jan 21.
We assess how the utilization of different DFT functionals for obtaining the equilibrium geometries and vibrational frequencies affect the description of the thermochemistry and subsequent calculation of the optical properties of a dihydroazulene-vinylheptafulvene photoswitch. The assessment covers nine popular DFT functionals (BLYP, B3LYP, CAM-B3LYP, M06-L, M06, M06-2X, PBE, PBE0, and ωB97X-D) in conjugation with five different Pople style basis sets (6-31+G(d), 6-31++G(d,p), 6-311+G(d), 6-311++G(d,p), and 6-311++G(3df,3pd)). It is identified that only CAM-B3LYP, M06-2X, and PBE0 are able to quantitatively describe the correct trends in the thermochemical properties. The subsequent calculation of the optical properties using the CAM-B3LYP functional shows that there is little difference in whether the CAM-B3LYP, M06-2X, or PBE0 functionals have been used to calculate the equilibrium geometries. Utilizing the identified functionals, we investigate how the number of electron withdrawing cyano substituents influence the thermochemistry and optical properties of the molecular photoswitch.
我们评估了使用不同的密度泛函理论（DFT）泛函来获得平衡几何结构和振动频率，对二氢薁-乙烯基七富烯光开关的热化学描述以及随后的光学性质计算会产生怎样的影响。该评估涵盖了九种常用的DFT泛函（BLYP、B3LYP、CAM-B3LYP、M06-L、M06、M06-2X、PBE、PBE0和ωB97X-D），并结合了五种不同的波普尔型基组（6-31+G(d)、6-31++G(d,p)、6-311+G(d)、6-311++G(d,p)和6-311++G(3df,3pd)）。结果发现，只有CAM-B3LYP、M06-2X和PBE0能够定量描述热化学性质的正确趋势。使用CAM-B3LYP泛函对光学性质进行后续计算表明，使用CAM-B3LYP、M06-2X或PBE0泛函来计算平衡几何结构，结果差异不大。利用已确定的泛函，我们研究了吸电子氰基取代基的数量如何影响分子光开关的热化学和光学性质。
