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An Incomplete Spin Transition Associated with a Z'=1?Z'=24?Crystallographic Symmetry Breaking.

ABSTRACT: Crystalline [FeL2 ][BF4 ]2 ?Me2 CO (L=N-[2,6-di{pyrazol-1-yl}pyrid-4-yl]acetamide) is high-spin at room temperature, and undergoes an abrupt, hysteretic spin-crossover at T1/2 =137?K (?T1/2 =14?K) that proceeds to about 50?% completeness. This is associated with a crystallographic phase transition, from phase?1 (P21 /c, Z=4) to phase?2 (P21 , Z=48). The cations associate into chains in the crystal through weak intermolecular ????? interactions. Phase?2 contains a mixture of high-spin and low-spin molecules, which are grouped into triads along these chains. The perchlorate salt [FeL2 ][ClO4 ]2 ?Me2 CO also adopts phase?1 at room temperature but undergoes a different phase transition near 135?K to phase?3 (P21 /c, Z=8) without a change in spin state.

SUBMITTER: Capel Berdiell I

PROVIDER: S-EPMC5972820 | biostudies-other | 2018 Apr

REPOSITORIES: biostudies-other

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An Incomplete Spin Transition Associated with a Z'=1→Z'=24 Crystallographic Symmetry Breaking.

Capel Berdiell Izar I Kulmaczewski Rafal R Cespedes Oscar O Halcrow Malcolm A MA

Chemistry (Weinheim an der Bergstrasse, Germany) 20171122 20

Crystalline [FeL2 ][BF4 ]2 ⋅Me2 CO (L=N-[2,6-di{pyrazol-1-yl}pyrid-4-yl]acetamide) is high-spin at room temperature, and undergoes an abrupt, hysteretic spin-crossover at T1/2 =137 K (ΔT1/2 =14 K) that proceeds to about 50 % completeness. This is associated with a crystallographic phase transition, from phase 1 (P21 /c, Z=4) to phase 2 (P21 , Z=48). The cations associate into chains in the crystal through weak intermolecular π⋅⋅⋅π ...[more]

PMID: 29111607

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