Spectroscopic, structural and magnetic investigations of iron(II) complexes based on 1-isopropyl- and 1-isobutyl-substituted tetrazole ligands

N. Hassan (1) , J. Stelzl (1) , P. Weinberger (1) , Gábor Molnár (2) , Azzedine Bousseksou (2) , F. Kubel (3) , K. Mereiter (3) , R. Boca (4) , W. Linert (1)

1 Institute of Applied Synthetic Chemistry
2 LCC - Laboratoire de chimie de coordination
3 Institute for Chemical Technologies and Analytics
4 Institute of Inorganic Chemistry

Two partly new [Fe(Intz)6](BF4)2 complexes with n = 3 and 4 (I3tz = 1-isopropyl-1H-tetrazole, I4tz = 1-isobutyl-1H-tetrazole) were synthesized and characterized by x-ray powder diffraction, magnetic susceptibility measurements, vibrational, electronic and 57Fe-Mossbauer spectroscopy as well as DSC. The [Fe(I3tz)6](BF4)2 complex was re-studied and shows an incomplete spin transition at Tc ∼ 109 K, while the [Fe(I4tz)6](BF4)2 features a complete but rather gradual spin transition with T1/2 = 223 K. In the lack of suitable crystals of [Fe(Intz)6](BF4)2 with n = 3 and 4, the authors synthesized crystals of [Ni(Intz)6](BF4)2 with n = 3 and 4, detd. their x-ray crystal structures, and proved them to be homeotypic with the resp. Fe-complexes by X-ray powder diffraction. DSC measurements showed an endothermic peak for the [Fe(I3tz)6](BF4)2 around T = 260 K not corresponding to a spin transition and suggesting a structural phase transition at this temp. A well-developed peak at Tp = 225 K matches the spin-transition temp. T1/2 = 223 K for [Fe(I4tz)6](BF4)2. [on SciFinder(R)]

Mots clés: magnetic property Mossbauer spectra mononuclear iron alkyl tetrazolate complex; lattice parameter mononuclear iron alkyl tetrazolate complex; mononuclear iron nickel alkyl tetrazolate complex prepn; crystal structure mononuclear nickel alkyl tetrazolate complex

Domaines: Chimie de coordination

N. Hassan, J. Stelzl, P. Weinberger, Gábor Molnár, Azzedine Bousseksou, et al.. Spectroscopic, structural and magnetic investigations of iron(II) complexes based on 1-isopropyl- and 1-isobutyl-substituted tetrazole ligands. Inorganica Chimica Acta, 2013, 396, pp.92-100. ⟨10.1016/j.ica.2012.10.007⟩. ⟨hal-00995062⟩