title: Homoleptic versus Heteroleptic Formation of Mononuclear Fe(II) Complexes with Tris-Imine Ligands.
abstract: We show a marked tendency of Fe(II) to form heteroleptic [Fe(L)(L')](ClO4)2 complexes from pairs of chelating tris-imine 3bpp, tpy, or 2bbp ligands. New synthetic avenues for spin crossover research become thus available, here illustrated with three new heteroleptic compounds with differing magnetic behaviors: [Fe(H4L1)(Cl-tpy)](ClO4)2·C3H6O (1), [Fe(H2L3)(Me3bpp)](ClO4)2·C3H6O (2), [Fe(H4L1)(2bbp)](ClO4)2·3C3H6O (3). Structural studies demonstrate that 1 is in the low-spin (LS) state up to 350 K, while complexes 2 and 3 are, by contrast, in the high-spin (HS) state down to 2 K, as corroborated through magnetic susceptibility measurements. Upon exposure to the atmosphere, the latter exhibits the release of three molecules of acetone per complex, turning into the solvent-free analogue [Fe(H4L1)(2bbp)](ClO4)2 (3a), through a single-crystal-to-single-crystal transformation. This guest extrusion process is accompanied by a spin switch, from HS to LS.
authors.affiliation: Departament de Química Inorgánica, Universitat de Barcelona , Diagonal 645, 08028, Barcelona, Spain.
authors.forename: Leoní A
authors.initials: LA
authors.lastname: Barrios
authors.affiliation: Departament de Química Inorgánica, Universitat de Barcelona , Diagonal 645, 08028, Barcelona, Spain.|Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC and Universidad de Zaragoza , Plaza San Francisco s/n, 50009 Zaragoza, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bartual-Murgui
authors.affiliation: Departament de Química Inorgánica, Universitat de Barcelona , Diagonal 645, 08028, Barcelona, Spain.
authors.forename: Eugènia
authors.initials: E
authors.lastname: Peyrecave-Lleixà
authors.affiliation: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1 , 263 Avenue du Général Leclerc, 35042 Cedex Rennes, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Le Guennic
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Lab , 1 Cyclotron Road, Berkeley, California 94720, United States.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Teat
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC and Universidad de Zaragoza , Plaza San Francisco s/n, 50009 Zaragoza, Spain.
authors.forename: Olivier
authors.initials: O
authors.lastname: Roubeau
authors.affiliation: Departament de Química Inorgánica, Universitat de Barcelona , Diagonal 645, 08028, Barcelona, Spain.
authors.forename: Guillem
authors.initials: G
authors.lastname: Aromí