Chiral Resolution of a Mn 3+ Spin Crossover Complex

Vibe Jakobsen (1) , Luke O'Brien (1) , Ghenadie Novitchi (2) , Helge Müller-Bunz (1) , Anne-Laure Barra (2) , Grace Morgan (1)

1 UCD - University College Dublin [Dublin]
2 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble

Enantiopure Δ and Λ forms of the spin crossover Mn3+ chelate complex [Mn{5-OCF3-sal2(323)}]+ were prepared by co-crystallization with the (R,R) and (S,S) forms of the chiral spiroborate anion bis[1,1′-binaphthyl-2,2′-diolato]boron. The absolute structures of the enantiomers were established by X-ray crystallography at 100 K and at 293 K. The enantiomeric purity of the Δ and Λ forms in acetonitrile solution was confirmed by circular dichroism spectroscopy in the UV/Vis range. Both enantiomers show a gradual and incomplete S = 1 ↔ S = 2 thermal spin crossover in the solid state but persist mainly in the spin triplet form between 3–200 K and retain a high percentage of spin triplet character at room temperature

Domaines: Chimie de coordination; Cristallographie

Vibe Jakobsen, Luke O'Brien, Ghenadie Novitchi, Helge Müller-Bunz, Anne-Laure Barra, et al.. Chiral Resolution of a Mn 3+ Spin Crossover Complex. European Journal of Inorganic Chemistry, 2019, 2019 (41), pp.4405-4411. ⟨10.1002/ejic.201900765⟩. ⟨hal-02311028⟩