The number and shape of lattice solvent molecules controls spin-crossover in an isomorphous series of crystalline solvate salts
Izar Capel Berdiell, Rafał Kulmaczewski, Namrah Shahid, Oscar Céspedes, Malcolm A. Halcrow
Abstract
Crystals of [FeL2][BF4]2·nMeCN (L = N-(2,6-di{pyrazol-1-yl}pyrid-4-yl)acetamide; n = 1 or 2) and [FeL2][ClO4]2·MeCN are isomorphous. When n = 1 the compounds exhibit an abrupt, hysteretic spin-transition below 200 K, but when n = 2 the material remains high-spin on cooling. [FeL2]X2·EtCN (X- = BF4- or ClO4-) are isomorphous with the MeCN solvates and undergo their spin-transition at almost the same temperature. However this now occurs in two-steps via a re-entrant mixed-spin intermediate phase, which correlates with crystallographic ordering of the bent propionitrile molecule.
Topics & Concepts
Spin crossoverCrystallographyMoleculeSeries (stratigraphy)ChemistryLattice (music)Phase transitionMaterials scienceCondensed matter physicsPhysicsOrganic chemistryBiologyPaleontologyAcousticsMagnetism in coordination complexesLanthanide and Transition Metal ComplexesElectron Spin Resonance Studies