title: Fe(III) in a low-spin state in caesium bis[3-ethoxysalicylaldehyde 4-methylthiosemicarbazonato(2-)-κ3O2,N1,S]ferrate(III) methanol monosolvate.
abstract: The synthesis and crystal structure (at 100 K) of the title compound, Cs[Fe(C11H13N3O2S2)2]·CH3OH, is reported. The asymmetric unit consists of an octahedral [Fe(III)(L)2](-) fragment, where L(2-) is 3-ethoxysalicylaldehyde 4-methylthiosemicarbazonate(2-) {systematic name: [2-(3-ethoxy-2-oxidobenzylidene)hydrazin-1-ylidene](methylamino)methanethiolate}, a caesium cation and a methanol solvent molecule. Each L(2-) ligand binds through the thiolate S, the imine N and the phenolate O atoms as donors, resulting in an Fe(III)S2N2O2 chromophore. The O,N,S-coordinating ligands are orientated in two perpendicular planes, with the O and S atoms in cis positions and the N atoms in trans positions. The Fe(III) cation is in the low-spin state at 100 K.
authors.affiliation: School of Engineering and Applied Science, Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham, West Midlands B4 7ET, England.
authors.forename: Robyn E
authors.initials: RE
authors.lastname: Powell
authors.affiliation: School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, West Midlands B4 7ET, England.
authors.forename: Carl H
authors.initials: CH
authors.lastname: Schwalbe
authors.affiliation: National Crystallography Service, Department of Chemistry, University of Southampton, Southampton SO17 1BJ, England.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Tizzard
authors.affiliation: School of Engineering and Applied Science, Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham, West Midlands B4 7ET, England.
authors.forename: Petra J van
authors.initials: PJ
authors.lastname: Koningsbruggen
mesh_terms: D002412:Cations / Q000737:chemistry*; D002586:Cesium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D000432:Methanol / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D002412:Cations; D005290:Ferric Compounds; D008024:Ligands; C000590246:caesium bis(3-ethoxysalicylaldehyde 4-methylthiosemicarbazonato(2-)-kappa3O2,N1,S)ferrate(III); D002586:Cesium; D000432:Methanol
keywords: FeIII spin-crossover behaviour; chromophores; crystal structure; iron(III); low-spin structures; switching behaviour; thiosemicarbazones