A study of structure and thermodynamic in the spin transition event in the [Fe2(Htrz)6(trz)3]Cl, [Fe4(Htrz)10(trz)5]Cl3, and [Fe6(Htrz)14(trz)7]Cl5 complexes using Hartree-Fock method)

Abstract

The purpose of this study was determined the structure data and the magnitude of ΔE, ΔH, ΔS, and ΔG in the [Fe2(Htrz)6(trz)3]Cl, the [Fe4(Htrz)10(trz)5]Cl3, and the [Fe6(Htrz)14(trz)7]Cl5 complexes in the low spin state and the high spin state. The computational chemistry calculations using the function/basis set UHF/6-31G(d). The computational chemistry using molecular structure modeling with two, four, and six Fe(II) ions. The results of this study showed that the structure of complex compounds in the low spin state was similar to the high spin state. The distance data between Fe(II) ions in the [Fe2(Htrz)6(trz)3]Cl complex at the low spin state was 3.851Å, while the high spin state was 4.019Å, the Fe4(Htrz)10(trz)5]Cl3 complex at the low spin state was 3.819Å–3.825Å, while the high spin state was 3.995Å–4.044Å, and the [Fe6(Htrz)14(trz)7]Cl5 complex at the low spin state was 3.801Å–3.822Å, while the high spin state was 3.949Å– 3.992Å. The thermodynamic quantities of ΔE, ΔH, ΔG, and ΔS in the [Fe2(Htrz)6(trz)3]Cl complex were -613.595kJ/mol, −613.595kJ/mol, -662.855kJ/mol, and 0.165kJ/mol.K, respectively; the Fe4(Htrz)10(trz)5]Cl3 complex were 1164.916kJ/mol, -1164.916 kJ/mol, -1224.851kJ/mol, and 0.201kJ/mol.K, respectively; and the [Fe6(Htrz)14(trz)7]Cl5 complexes were 109060.629kJ/mol, 109060.629 kJ/mol, 108926.728kJ/mol, and 0.447kJ/mol.K, respectively.