title: A novel crystal structure of {tris[4-(1H-pyrazol-3-yl-κN(2))-3-azabut-3-enyl]amine-κN}iron(II) bis(tetrafluoridoborate) methanol monosolvate featuring a low-spin configuration.
abstract: Mononuclear complexes are good model systems for evaluating the effects of different ligand systems on the magnetic properties of iron(II) centres. A novel crystal structure of the title compound, [Fe(C18H24N10)](BF4)2·CH3OH, with one molecule of methanol per formula unit exhibits a strictly sixfold coordination sphere associated with a low-spin configuration at the metal centre. The incorporated methanol solvent molecule promotes extended hydrogen-bonding networks between the tetrafluoridoborate anions and the cationic units. A less constrained crystal structure regarding close contacts between the tetrafluoridoborate anions and the cationic units allows a spin transition which is inhibited in the previously published hydrate of the title compound.
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
authors.forename: Niklas
authors.initials: N
authors.lastname: Struch
authors.affiliation: Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Schnakenburg
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Lützen
keywords: crystal structure; iron(II) complexes; low-spin configuration; spin-crossover