Accurate predictions of the EPR parameters in planar cobalt(II) complexes by hybrid density functional theory

The hybrid density functional theory is applied to calculate the electron paramagnetic resonance parameters, i.e, the g- and A-tensors of some planar Cobalt(II) complexes with a C2v symmetry. Calculations were done for four systems: Co(acacen), Co(tacacen), Co(seacacen) and Co(sacsac)2. The following hybrid functionals were employed: B3LYP, B3PW91, mPW1PW91 and PBE0. The expected large deviation of the g- and A-tensors is well reproduced, and is in very good agreement with the experimental observations. Comparative study shows that the PBE0 hybrid model yields the best agreement with experimental data.

Graphical abstractFour hybrid DFT/HF functionals (PBE0, mPW1PW91, B3LYP and B3PW91) are used to calculate the EPR parameters, i.e., the g- and the A-tensors of four planar cobalt(II) complexes (Co(acacen), Co(tacacen), Co(seacacen) and Co(sacsac)). The large anisotropy of the EPR parameters is also investigated. The parameter-free hybrid functional PBE0 leads to the most accurate results comparing to the experimental data.Figure optionsDownload full-size imageDownload as PowerPoint slide