title: Spin-Crossover in a Pseudo-tetrahedral Bis(formazanate) Iron Complex.
abstract: Spin-crossover in a pseudo-tetrahedral bis(formazanate) iron(II) complex (1) is described. Structural, magnetic, and spectroscopic analyses indicate that this compound undergoes thermal switching between an S=0 and an S=2 state, which is very rare in four-coordinate complexes. The transition to the high-spin state is accompanied by an increase in Fe-N bond lengths and a concomitant contraction of intraligand N-N bonds. The latter suggests that stabilization of the low-spin state is due to the π-acceptor properties of the ligand. One-electron reduction of 1 leads to the formation of the corresponding anion, which contains a low-spin (S=1/2) Fe(I) center. The findings are rationalized by electronic structure calculations using density functional theory.
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Raquel
authors.initials: R
authors.lastname: Travieso-Puente
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: J O P
authors.initials: JO
authors.lastname: Broekman
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Mu-Chieh
authors.initials: MC
authors.lastname: Chang
authors.affiliation: Institut für Anorganische Chemie, Georg-August-Universität Göttingen , Tammannstraße 4, 37077 Göttingen, Germany.
authors.forename: Serhiy
authors.initials: S
authors.lastname: Demeshko
authors.affiliation: Institut für Anorganische Chemie, Georg-August-Universität Göttingen , Tammannstraße 4, 37077 Göttingen, Germany.
authors.forename: Franc
authors.initials: F
authors.lastname: Meyer
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: Otten