Department of Chemistry and Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas , Denton, Texas 76203-5017, United States.
J Phys Chem A. 2013 Jun 20;117(24):5140-8. doi: 10.1021/jp312690e. Epub 2013 Jun 7.
Studies were focused on late 3d and 4d transition metal ion (Fe, Co, Ni, Cu, Ru, Rh, Pd, and Ag) mediated activation of dimethyl ether, to investigate the intrinsic catalytic properties of metals on C-O bond cleavage. A set of density functional (DFT) methods (BLYP, B3LYP, M06, M06-L, B97-1, B97-D, TPSS, and PBE0) with aug-cc-pVTZ were utilized, and the results were calibrated with CCSD(T)/CBS. The utility of CCSD(T)/CBS calculations for these systems was validated by MRCI/aug-cc-pVTZ calculations. Calculations showed an interesting energetic trend as a function of metal; earlier transition metals tend to give smaller reaction barriers and more exergonic reactions than later metals. This applies to both 3d and 4d systems. For the performance of DFT functionals, PBE0 gave the lowest root mean squared deviations (RMSDs) in terms of both reaction energies and barriers for both 3d and 4d systems, compared to the other functionals. Our studies found that the percentage of Hartree-Fock (HF) exchange plays an important role in the accuracy of DFT methods for these systems, and 26% HF exchange for 3d systems and 34% HF exchange for 4d systems gave the lowest RMSDs.
研究集中在晚期 3d 和 4d 过渡金属离子（Fe、Co、Ni、Cu、Ru、Rh、Pd 和 Ag）介导的二甲醚活化，以研究金属对 C-O 键断裂的固有催化性质。采用了一组密度泛函（DFT）方法（BLYP、B3LYP、M06、M06-L、B97-1、B97-D、TPSS 和 PBE0）与 aug-cc-pVTZ，并用 CCSD(T)/CBS 进行了校准。CCSD(T)/CBS 计算对这些体系的有效性通过 MRCI/aug-cc-pVTZ 计算得到了验证。计算表明，金属的能量趋势很有趣；早期过渡金属比后期金属更倾向于给出更小的反应势垒和更放能的反应。这适用于 3d 和 4d 体系。对于 DFT 函数的性能，PBE0 在 3d 和 4d 体系的反应能和势垒方面都给出了最低的均方根偏差（RMSD），与其他函数相比。我们的研究发现，Hartree-Fock（HF）交换的百分比在这些体系的 DFT 方法的准确性中起着重要作用，对于 3d 体系，HF 交换的 26%和对于 4d 体系，HF 交换的 34%给出了最低的 RMSD。
