biostudies-literatureBernhardt PVNorges ForskningsrådL. Meltzers HøyskolefondEuropean Cooperation in Science and TechnologyAustralian Research CouncilEngineering and Physical Sciences Research Council5082-5085https://www.ebi.ac.uk/biostudies/studies/S-EPMC5988046biostudies-literatureUnknown24(20)Single crystal structural analysis of [FeII (tame)2 ]Cl2 ⋅MeOH (tame=1,1,1-tris(aminomethyl)ethane) as a function of temperature reveals a smooth crossover between a high temperature high-spin octahedral d6 state and a low temperature low-spin ground state without change of the symmetry of the crystal structure. The temperature at which the high and low spin states are present in equal proportions is T1/2 =140 K. Single crystal, variable-temperature optical spectroscopy of [FeII (tame)2 ]Cl2 ⋅MeOH is consistent with this change in electronic ground state. These experimental results confirm the spin activity predicted for [FeII (tame)2 ]2+ during its de novo artificial evolution design as a spin-crossover complex [Chem. Inf.<h4>Model</h4>2015, 55, 1844], offering the first experimental validation of a functional transition-metal complex predicted by such in silico molecular design methods. Additional quantum chemical calculations offer, together with the crystal structure analysis, insight into the role of spin-passive structural components. A thermodynamic analysis based on an Ising-like mean field model (Slichter-Drickammer approximation) provides estimates of the enthalpy, entropy and cooperativity of the crossover between the high and low spin states.Chemistry (Weinheim an der Bergstrasse, Germany)Spin Crossover in a Hexaamineiron(II) Complex: Experimental Confirmation of a Computational Prediction.PMC5988046EP/K0129402017/3273205273COST Action CM1305262370Deeth RJFoscato MBrosius VBernhardt PVRiley MJChernyshov DJensen VRBilyj JKTornroos KWMertes NfalseSpin Crossover in a Hexaamineiron(II) Complex: Experimental Confirmation of a Computational Prediction.Single crystal structural analysis of [FeII (tame)2 ]Cl2 ⋅MeOH (tame=1,1,1-tris(aminomethyl)ethane) as a function of temperature reveals a smooth crossover between a high temperature high-spin octahedral d6 state and a low temperature low-spin ground state without change of the symmetry of the crystal structure. The temperature at which the high and low spin states are present in equal proportions is T1/2 =140 K. Single crystal, variable-temperature optical spectroscopy of [FeII (tame)2 ]Cl2 ⋅MeOH is consistent with this change in electronic ground state. These experimental results confirm the spin activity predicted for [FeII (tame)2 ]2+ during its de novo artificial evolution design as a spin-crossover complex [Chem. Inf.<h4>Model</h4>2015, 55, 1844], offering the first experimental validation of a functional transition-metal complex predicted by such in silico molecular design methods. Additional quantum chemical calculations offer, together with the crystal structure analysis, insight into the role of spin-passive structural components. A thermodynamic analysis based on an Ising-like mean field model (Slichter-Drickammer approximation) provides estimates of the enthalpy, entropy and cooperativity of the crossover between the high and low spin states.2018-01-01T00:00:00Z2018 Apr2024-10-18T23:27:43.737Z2019-03-26T23:48:54ZS-EPMC59880462931588310.1002/chem.201705439