Accurate prediction of vertical electronic transitions of Ni(II) coordination compounds via time dependent density functional theory

Abstract

Time dependent density functional theory calculations are completed for five Ni(II) complexes formed by polydentate peptides to predict the electronic absorption spectrum. The ligands examined were glycyl-glycyl-glycine (GGG), glycyl-glycyl-glycyl-glycine (GGGG), glycyl-glycyl-histidine (GGH), glycyl-glycyl-cysteine (GGC), and triethylenetetramine (trien). Fifteen functionals and two basis sets were tested. On the basis of the mean absolute percent deviation (MAPD), the ranking among the functionals is:ing the basis sets, the triple-f def2-TZVP performs better than the double-f LANL2DZ. With the functional HSE06 and basis set def2-TZVP the MAPD with respect to the experimental k max is 1.65% with a standard deviation of 1.26%. The absorption electronic spectra were interpreted in terms of vertical excitations between occupied and virtual MOs based on Ni-d atomic orbitals. The electronic structure of the Ni(II) species is also discussed. K E Y W O R D S electronic structure, nickel, peptides, time dependent density functional theory, UV-Vis spectroscopy 1 | I N TR ODU C TI ONThe prediction of the structure, reactivity, and stability of a chemical compound has always been a big challenge not only in chemistry, but also in physics and biology. During the past decades, computational methods allowed the chemists to calculate the structure, molecular properties, and energetics of many chemical species. Among these methods, density functional theory (DFT) [1] has reached an enormous popularity and many reviews have been published. [2][3][4][5][6][7][8][9][10] The main advantage of DFT is that many packages are available, commercially or free of charge, which allow one calculations on large molecules in an user friendly manner; nowadays, molecules with more than one hundred atoms can be treated routinely. At the Int J Quantum Chem. 2018;e25655. https://doi.org/10.1002/qua.25655

DFT Protocol for EPR Prediction of Paramagnetic Cu(II) Complexes and Application to Protein Binding Sites

“…Worst performance was obtained with TPSSh (10% HF exchange), BHandHLYP (50% HF exchange), MPW1PW91 (25% HF exchange), the double hybrid B2PLYP (53% HF exchange), and the range separated ω-B97x-D (short range HF exchange 22.2%, long range HF exchange 100%). Finally, the M06 global hybrid functional (27% HF exchange), in contrast to its good performance in the prediction of thermochemistry, kinetic, chemical structures, and non-covalent interactions [74,75], cannot be suggested to simulate spectroscopic data, confirming previous published data [29]. Considering the strong dependency of A z on the core-and valence shell electron polarization, the reason could be found in the low accuracy of the functionals with a large number of empirical parameters in the prediction of the electronic density around the nucleus with respect to the functionals less parameterized, as recently reported by Medvedev et al [76].…”

“…Density functional theory methods allows to calculate the structure, energy, and molecular properties with great accuracy. Concerning the spectroscopic behavior of the transition metal ions, IR, UV-vis, CD, and magnetic circular dichroism (MCD) spectra were simulated, but only for nuclear magnetic resonance (NMR) and EPR-and UV-Vis in some rare cases [29]-the agreement with the experimental data can be quantitative [30][31][32][33][34][35][36][37].…”

Actinide Endohedral and Exohedral Cubic Siloxanes: An(IV)@(HSiO1.5)8 and An(IV)&(RSiO1.5)8 (An = U, Np, Pu; R = H, Cl, OH)

“…In addition, TD‐DFT have been implemented to simulate the UV/Vis spectra (Figure ) at PBE0‐ZORA/def2‐TZVPP‐SARC level. The PBE0 functional has been proven to work well for TD‐DFT calculation of transition metal complexes . In the simulation of UV/Vis spectra, a Gaussian function with fwhm of 0.8 eV has been selected to broaden discrete line.…”

The effect of side chains on the complex formation processes of N-terminally free hexapeptides containing C-terminal cysteinyl functions

“…33 This model and the B3P86 functional are frequently used in the literature because of their high degree of accuracy in the prediction of the structures of the first-row transition metal complexes and in the calculation of their relative free energies. [34][35][36] Single-point frequency calculations were carried out for the ground state geometries at the same level of theory which represented true minima on the potential energy surface. The relative free energy of the complexes was calculated from these single-point frequency calculations.…”