Benchmark study of density functionals for the insertions of olefin and polar monomers catalyzed by α–diimine palladium complexes

The performance of density functionals has been tested for the insertions of ethylene, methyl acrylate (MA), and vinyl bromide (VB) catalyzed by α-diimine palladium complexes. By screening 67 density functionals and comparing with experimental data, 7 hybrid GGA and 4 hybrid meta-GGA functionals showed better performance in the insertions of both ethylene and MA, and could be therefore suitable for ethylene-MA copolymerization. Meanwhile, three GGA (PW91PW91, HCTH, HCTH407), two meta-GGA (TPSSTPSS, tHCTH), 4 hybrid GGA and 6 hybrid meta-GGA functionals perform well in ethylene-VB copolymerization. Besides, nine D3 or D3BJ augmented functionals are found to be suitable for both copolymerization systems. The D2 dispersion correction overestimated insertion energy barriers of these monomers and is unsuitable for such copolymerization. In addition, the double-zeta basis set is found to be sufficient for solvation single-point calculation of these systems.