How Accurate Can a Local Coupled Cluster Approach Be in Computing the Activation Energies of Late-Transition-Metal-Catalyzed Reactions with Au, Pt, and Ir?

Abstract

To improve the accuracy of local coupled cluster (LCC) methods in computing activation energies, we propose herein a new computational scheme. Its applications to various types of late-transition-metal-catalyzed reactions involving Au, Pt, and Ir indicate that the new corrective approach for LCC methods can downsize the mean unsigned deviation and maximum deviation, from the CCSD(T)/CBS reference, to about 0.3 and 0.9 kcal/mol. Using this method, we also calibrated the performance of popular density functionals, with respect to the same test set of reactions. It is concluded that the best functional is the general-purpose double hybrid functional B2GP-PLYP. Other well-performing functionals include the "kinetic" functionals M06-2X and BMK, which have a large percentage of HF exchange, and general-purpose functionals like PBE0 and wB97X. Comparatively, general-purpose functionals like PBE0 and TPSSh perform much better than the tested "kinetic" functionals for Pt-/Ir-catalyzed reactions, while the opposite is true for Au-catalyzed reactions. In contrast, wB97X performs more uniformly in these two classes of reactions. These findings hint that even within the scope of late transition metals, different types of reactions may require different types of optimal DFT methods. Empirical dispersion correction of DFT was found to have a small or no effect on the studied reactions barriers.

Comparative Assessment of DFT Performances in Ru- and Rh-Promoted σ-Bond Activations

“…For reaction barrier and reaction energy, the correlation analysis results for eight bestperforming functionals with the smallest MUDs(tot) (selected from the MUD data with DFT dispersion correction except the four new Minnesota functionals N12, N12SX, MN12L, and MN12SX) are shown in Figures 2 and 3, respectively. First we can see that the correlations R 2 are at least 0.94 in both activation energy and reaction energy trend analysis, which 95 and late transition metals Rh, 79 Pd, 79 Ir, 79,99 and Pt. 79,99 For early transition metals Zr, M06-2X was found to perform extremely well for C−H activation of σ-bond metathesis mechanism, with an absolute deviation of merely about 0.2 kcal/mol from the reference coupled cluster data.…”

Computational Studies of Synthetically Relevant Homogeneous Organometallic Catalysis Involving Ni, Pd, Ir, and Rh: An Overview of Commonly Employed DFT Methods and Mechanistic Insights

“…89 Also, recently H. Chen and co-workers benchmarked the C−H activation of a small methane molecule by Pd, Ir, and Rh pincer complexes that employed several different pincer ligands. On the basis of LCCSD(T) 90 reference data, the benchmark study showed that for the C−H activation step, in terms of mean unsigned deviation (MUD), B3LYP (MUD = 1.17) was the most accurate DFT method followed by B2GPLYP (MUD = 2.20), 91 B2PLYP (MUD = 2.26), 92 and PBE0 (MUD = 2.27). 93 Nonetheless, given that many Pd-, Ni-, Rh-, and Ir-mediated transformations involve bimolecular processes and bear large ligands, the quantitative and qualitative accuracy of energy calculations has in many cases been greatly influenced by dispersive effects.…”

Assessment of DFT Methods for Computing Activation Energies of Mo/W-Mediated Reactions

“…Before we discuss the detailed effects of DFT empirical dispersion correction for Mo/W-mediated reactions, it is notable that M06 series DFs are almost not affected by DFT-D3 corrections (the MUDs change by less than 0.09 kcal/mol), which is consistent with the observations in our previous work for other transition metals. [115][116][117]122 This is presumably due to the parametrization of these DFs to account for dispersion interactions to certain extent. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 TPSSh, B2-PLYP, and B2GP-PLYP) have been collected in Table 6.…”