A new iron(iii) complex, [Et3NH][FeIII(L2-)2] (1) with a substituted o-aminophenol based ligand is reported. Complex 1 is an anionic complex with a triethylammonium cation in the lattice. It contains two O,O,N-coordinated o-iminobenzosemiquinonate(2-)radical anions with an Fe(iii) centre in a high-spin configuration. The crystal structure of 1 was determined by X-ray diffraction, which revealed a trigonal prismatic coordination environment whose electronic structure was established by various physical methods including EPR, MÃ¶ssbauer spectroscopy and variable-temperature (2-300 K) magnetic susceptibility measurements. Electrochemical analysis indicated primarily ligand-centred redox processes. Complex 1 retained the high-spin character of Fe(iii) throughout the temperature range studied (2-300 K) and exhibited, as expected, strong antiferromagnetic coupling operating between two radicals (SR= 1/2) and the high-spin Fe(iii) centre (SFe= 5/2), yielding a St= 3/2 as the ground state. This was confirmed by means of DFT calculations (M06-2X/6-31+Gâ) and a spin density analysis of the high spin and low spin configurations.
A trigonal prismatic anionic iron(III) complex of a radical o-iminobenzosemiquinonate derivative: Structural and spectral analyses / Saha, Sandeepta; Roy Choudhury, Chirantan; Gomez-Garcia, Carlos J.; Benmansour, Samia; Garribba, Eugenio; Frontera, Antonio; Rizzoli, Corrado; Mitra, Samiran. - In: NEW JOURNAL OF CHEMISTRY. - ISSN 1144-0546. - 41:15(2017), pp. 7283-7291. [10.1039/c7nj01212h]