Coupled Cluster Benchmark of New DFT and Local Correlation Methods: Mechanisms of Hydroarylation and Oxidative Coupling Catalyzed by Ru(II, III) Chloride Carbonyls

We have evaluated
a set of accurate canonical CCSD­(T) energies
for stationary points on the potential energy surface for Ru­(II, III)
chloride carbonyl catalysis of two competing reactions between benzene
and methyl acrylate (MA), namely, hydroarylation and oxidative coupling.
We have then applied this set to evaluate the performance of localized
orbital coupled-cluster methods and several new and common density
functionals. We find that (a) DLPNO-CCSD­(T) with TightPNO cutoffs
is an acceptable substitute for full canonical CCSD­(T) calculations
on this system; (b) for the closed-shell systems where it could be
applied, LNO-CCSD­(T) with tight convergence criteria is very close
to the canonical results; (c) the recent ωB97X-V and ωB97M-V
functionals exhibit superior performance to commonly used DFT functionals
in both closed- and open-shell calculations; (d) the revDSD-PBEP86
revision of the DSD-PBEP86 double hybrid represents an improvement
over the original, even though transition metals were not involved
in its parametrization; and (e) DSD-SCAN and DOD-SCAN show comparable
efficiency. Most tested (meta)-GGA and hybrid density functionals
perform better for open-shell than for closed-shell complexes; this
is not the case for the double hybrids considered.