title: Single-crystal to single-crystal structural transformation and photomagnetic properties of a porous iron(II) spin-crossover framework.
abstract: The porous coordination framework material, Fe(NCS)2(bped)2 x 3EtOH, SCOF-3(Et) (where bped is dl-1,2-bis(4'-pyridyl)-1,2-ethanediol), displays a spin-crossover (SCO) transition that has been stimulated both thermally and by light irradiation. The one-step thermal SCO (70-180 K) is sensitive to the presence of molecular guests, with a more gradual transition (70-225 K) apparent following the desorption of ethanol molecules that hydrogen bond to the spin centers. Additional intraframework hydrogen-bonding interactions stabilize the vacant one-dimensional pore structure of the apohost, SCOF-3, despite a dramatic single-crystal to single-crystal (SC-SC) structural change upon removal of the guests. Comprehensive structural analyses throughout this transformation, from primitive orthorhombic (Pccn) to body-centered tetragonal (I4/mcm), reveal a flexing of the framework and a dilation of the channels, with an accompanying subtle distortion of the iron(II) coordination geometry. Photomagnetic measurements of the light-induced excited spin state trapping (LIESST) effect have been used to assess the degree of cooperativity in this system.
authors.affiliation: School of Chemistry, University of Sydney, NSW 2006, Australia.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Neville
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Halder
authors.forename: Karena W
authors.initials: KW
authors.lastname: Chapman
authors.forename: Martin B
authors.initials: MB
authors.lastname: Duriska
authors.forename: Peter D
authors.initials: PD
authors.lastname: Southon
authors.forename: John D
authors.initials: JD
authors.lastname: Cashion
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Létard
authors.forename: Boujemaa
authors.initials: B
authors.lastname: Moubaraki
authors.forename: Keith S
authors.initials: KS
authors.lastname: Murray
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Kepert