TY - JOUR
T1 - Spin crossover in a 3,5-bis(2-pyridyl)-1,2,4-triazolate-bridged dinuclear iron(II) complex [{Fe(NCBH3)(py)}2-(μ-L 1)2] - Powder versus single crystal study
AU - Schneider, Caspar J.
AU - Cashion, John D.
AU - Chilton, Nicholas F.
AU - Etrillard, Céline
AU - Fuentealba, Mauricio
AU - Howard, Judith A.K.
AU - Létard, Jean François
AU - Milsmann, Carsten
AU - Moubaraki, Boujemaa
AU - Sparkes, Hazel A.
AU - Batten, Stuart R.
AU - Murray, Keith S.
PY - 2013/2
Y1 - 2013/2
N2 - The structural characteristics and physical properties of the 3,5-bis(2-pyridyl)-1,2,4-triazolate (L1) bridged dinuclear iron(II) spin-crossover complex [{Fe(NCBH3)(py)}2(μ-L1) 2] (1) in both powder (1p) and single crystal (1c) forms have been investigated. Both forms of [{Fe(NCBH3)(py)}2(μ-L 1)2] display a thermally induced spin transition; however, the transitions have different T1/2 values and different degrees of spin conversion. Both forms display the photomagnetic light-induced excited spin-state trapping (LIESST) effect as well as reverse LIESST and have been compared by Raman spectral and powder X-ray diffraction methods, which indicate that they are polymorphs. The single crystal form 1c shows a "half" spin transition and has been further characterised at temperatures above and below the spin transition by low temperature crystallographic methods including single crystal LIESST experiments (at 40 K) and by Mössbauer spectroscopy; thus, the nature of the [HS-LS] form and the different spin isomers were revealed. To complement the experimental results, compound 1 and several other related FeII dinuclear spin-crossover compounds have been evaluated by quantum-chemical DFT calculations. Additionally, the susceptibilities for the powder form 1p, which displays a complete two-step spin-crossover, were also fitted to a phenomenological model for dinuclear spin-crossover complexes.
AB - The structural characteristics and physical properties of the 3,5-bis(2-pyridyl)-1,2,4-triazolate (L1) bridged dinuclear iron(II) spin-crossover complex [{Fe(NCBH3)(py)}2(μ-L1) 2] (1) in both powder (1p) and single crystal (1c) forms have been investigated. Both forms of [{Fe(NCBH3)(py)}2(μ-L 1)2] display a thermally induced spin transition; however, the transitions have different T1/2 values and different degrees of spin conversion. Both forms display the photomagnetic light-induced excited spin-state trapping (LIESST) effect as well as reverse LIESST and have been compared by Raman spectral and powder X-ray diffraction methods, which indicate that they are polymorphs. The single crystal form 1c shows a "half" spin transition and has been further characterised at temperatures above and below the spin transition by low temperature crystallographic methods including single crystal LIESST experiments (at 40 K) and by Mössbauer spectroscopy; thus, the nature of the [HS-LS] form and the different spin isomers were revealed. To complement the experimental results, compound 1 and several other related FeII dinuclear spin-crossover compounds have been evaluated by quantum-chemical DFT calculations. Additionally, the susceptibilities for the powder form 1p, which displays a complete two-step spin-crossover, were also fitted to a phenomenological model for dinuclear spin-crossover complexes.
KW - Density functional calculations
KW - Iron
KW - LIESST
KW - N ligands
KW - Polymorphism
KW - Spin crossover
UR - http://www.scopus.com/inward/record.url?scp=84875719141&partnerID=8YFLogxK
U2 - 10.1002/ejic.201201075
DO - 10.1002/ejic.201201075
M3 - Article
AN - SCOPUS:84875719141
SN - 1434-1948
SP - 850
EP - 864
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
IS - 5-6
ER -