TY - JOUR
T1 - Unusual Magneto-Structural Features of the Halo-Substituted Materials [FeIII(5-X-salMeen)2]Y
T2 - a Cooperative [HS-HS]↔[HS-LS] Spin Transition
AU - Al-Azzani, Mariam A.
AU - Al-Mjeni, Faizah
AU - Mitsuhashi, Ryoji
AU - Mikuriya, Masahiro
AU - Al-Omari, Imaddin A.
AU - Robertson, Craig C.
AU - Bill, Eckhard
AU - Shongwe, Musa S.
N1 - Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/4/9
Y1 - 2020/4/9
N2 - X-ray structures of the halo-substituted complexes [FeIII(5-X-salMeen)2]ClO4 (X=F, Cl, Br, I) [salMeen=N-methyl-N-(2-aminoethyl)salicylaldiminate]at RT have revealed the presence of two discrete HS complex cations in the crystallographic asymmetric unit with two perchlorate counter ions linking them by N−Hamine⋅⋅⋅Operchlorate interactions. At 90 K, the two complex cations are distinctly HS and LS, a rare crystallographic observation of this coexistence in the FeIII-salRen (R=alkyl) spin-crossover (SCO) system. At both temperatures, crystal packing shows dimerization through C−Himine⋅⋅⋅Ophenolate interactions, a key feature for SCO cooperativity. Moreover, there are noncovalent contacts between the complex cations through type-II halogen-halogen bonds, which are novel in this system. The magnetic profiles and Mössbauer spectra concur with the structural analyses and reveal 50 % SCO of the type [HS-HS]↔[HS-LS] with a broad plateau. In contrast, [FeIII(5-Cl-salMeen)2]BPh4⋅2MeOH is LS and exhibits a temperature-dependent crystallographic phase transition, exemplifying the influence of lattice solvents and counter ions on SCO.
AB - X-ray structures of the halo-substituted complexes [FeIII(5-X-salMeen)2]ClO4 (X=F, Cl, Br, I) [salMeen=N-methyl-N-(2-aminoethyl)salicylaldiminate]at RT have revealed the presence of two discrete HS complex cations in the crystallographic asymmetric unit with two perchlorate counter ions linking them by N−Hamine⋅⋅⋅Operchlorate interactions. At 90 K, the two complex cations are distinctly HS and LS, a rare crystallographic observation of this coexistence in the FeIII-salRen (R=alkyl) spin-crossover (SCO) system. At both temperatures, crystal packing shows dimerization through C−Himine⋅⋅⋅Ophenolate interactions, a key feature for SCO cooperativity. Moreover, there are noncovalent contacts between the complex cations through type-II halogen-halogen bonds, which are novel in this system. The magnetic profiles and Mössbauer spectra concur with the structural analyses and reveal 50 % SCO of the type [HS-HS]↔[HS-LS] with a broad plateau. In contrast, [FeIII(5-Cl-salMeen)2]BPh4⋅2MeOH is LS and exhibits a temperature-dependent crystallographic phase transition, exemplifying the influence of lattice solvents and counter ions on SCO.
KW - crystallographic phase transition
KW - electronic and electrochemical processes
KW - ferric spin crossover
KW - noncovalent interactions
KW - spin-transition plateau
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U2 - 10.1002/chem.201904744
DO - 10.1002/chem.201904744
M3 - Article
C2 - 31826307
AN - SCOPUS:85082933444
SN - 0947-6539
VL - 26
SP - 4766
EP - 4779
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 21
ER -