DFT/TD-DFT study of the spin transition complex [Fe(pmea)(NCS)2]

Abstract

The spin crossover (SCO) compound [Fe(pmea)(NCS)(2)] (where pmea symbolizes the ligand bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine) has been studied by DFT/TD-DFT methods. Several density functionals and basis sets were used in the calculations to obtain optimized geometries of the compound in the low-(LS), intermediate-(IS) and high-spin (HS) states. The vibrational modes and IR spectra, spin splittings energies, excited states and UV/vis absorption spectra were calculated. From the TD-DFT calculations, it can be inferred that this complex may act as a reversible optical switch via the LIESST effect and its reverse process.