title: Four-site cooperative spin crossover in a mononuclear Fe(II) complex.
abstract: Round and round: A mononuclear Fe(II)  complex (see picture) with an N(4)S(2) coordination set has been characterized in four polymorphic forms. Two of the polymorphs display four-site cooperative spin crossover (SCO), shown conclusively by the crystal structure of a fully ordered 1:3 high-spin/low-spin state. The presence of S donor atoms in SCO-active compounds is unusual, and further investigation of Fe(II)  complexes for SCO activity is warranted.
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Lennartson
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bond
authors.forename: Stergios
authors.initials: S
authors.lastname: Piligkos
authors.forename: Christine J
authors.initials: CJ
authors.lastname: McKenzie
mesh_terms: D018360:Crystallography, X-Ray; D005296:Ferrous Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D005296:Ferrous Compounds