Heteronuclear Iron(III)-Schiff Base Complexes with the Hexacyanidocobaltate(III) Anion: On the Quest To Understand the Governing Factors of Spin Crossover

Heteronuclear Iron(III)-Schiff Base Complexes with the Hexacyanidocobaltate(III) Anion: On the Quest To Understand the Governing Factors of Spin Crossover

Článek WoS

Two heteronuclear compounds (1 and 2) containing three ferric centers linked in facial-like mode with the magnetically silent hexacyanidocobaltate(III) anion were prepared and studied. The structural investigation revealed that both compounds are tetranuclear complexes with molecular formulas of [{Fe(L1)NC}(3)Co(CN)(3)]center dot 2CH(3) OH center dot 2.5CH(3)CN (1) and [{Fe(L2)NC}(3)Co(CN)(3)]center dot 2H(2)O center dot]CH3OH (2). The magnetic properties of both complexes are controlled by the molecular design of the corresponding pentadentate Schiff base anions L1(2-) and L2(2-). While compound 2 with a symmetric ligand prepared from salicylaldehyde shows high-spin state properties, compound 1 containing the asymmetric ligand with naphthalene units either is low-spin in its solvated form or shows a gradual but hysteretic spin crossover event when desolvated. The magnetic behavior was analyzed with respect to the Ising-like model and spin Hamiltonian, respectively, and the results were confronted with ab initio calculations. Additionally, the influence of structural features, lattice solvent molecules, the distribution of electronic terms, and active orbitals on the spin state properties of reported complexes is discussed.

Two heteronuclear compounds (1 and 2) containing three ferric centers linked in facial-like mode with the magnetically silent hexacyanidocobaltate(III) anion were prepared and studied. The structural investigation revealed that both compounds are tetranuclear complexes with molecular formulas of [{Fe(L1)NC}(3)Co(CN)(3)]center dot 2CH(3) OH center dot 2.5CH(3)CN (1) and [{Fe(L2)NC}(3)Co(CN)(3)]center dot 2H(2)O center dot]CH3OH (2). The magnetic properties of both complexes are controlled by the molecular design of the corresponding pentadentate Schiff base anions L1(2-) and L2(2-). While compound 2 with a symmetric ligand prepared from salicylaldehyde shows high-spin state properties, compound 1 containing the asymmetric ligand with naphthalene units either is low-spin in its solvated form or shows a gradual but hysteretic spin crossover event when desolvated. The magnetic behavior was analyzed with respect to the Ising-like model and spin Hamiltonian, respectively, and the results were confronted with ab initio calculations. Additionally, the influence of structural features, lattice solvent molecules, the distribution of electronic terms, and active orbitals on the spin state properties of reported complexes is discussed.

STATE PERTURBATION-THEORY; MOLECULAR-ORBITAL METHODS; BASIS-SETS; VALENCE; COORDINATION; LIGANDS; IMPLEMENTATION; ENERGIES; BEHAVIOR; EXAMPLE

STATE PERTURBATION-THEORY; MOLECULAR-ORBITAL METHODS; BASIS-SETS; VALENCE; COORDINATION; LIGANDS; IMPLEMENTATION; ENERGIES; BEHAVIOR; EXAMPLE

PAVLIK, J.; MASÁROVÁ, P.; NEMEC, I.; FUHR, O.; RUBEN, M.; ŠALITROŠ, I.

2021

02.03.2020

AMER CHEMICAL SOC

WASHINGTON

1520-510X

INORGANIC CHEMISTRY

59

5

Spojené státy americké

2747

2757

11

https://pubs.acs.org/doi/10.1021/acs.inorgchem.9b03097