Structure and electronic properties of heme complexes with various ligands

The electronic structure, equilibrium geometry, and atomic backbone dynamics of a number of heme complexes at 310 K were studied by quantum chemistry and molecular dynamics. It was found that the type of coordination of the imidazole ring of histidine affects the molecular oxygen binding constant in the complexes. At the same time, NO and O₂ have different trans influence on the ligand in the fifth coordination position. It is shown that temperature has a significant effect on the change in the geometry and electronic structure of such complexes, as well as on the strength and reactivity of bonds.