Stepwise spin transition in a mononuclear iron(II) complex with unusually wide plateau
| hal.structure.identifier | Department of Chemistry and Biochemistry | |
| dc.contributor.author | WEBER, Birgit | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | CARBONERA, Chiara | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | DESPLANCHES, Cédric | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | LÉTARD, Jean-François | |
| dc.date.issued | 2008 | |
| dc.identifier.issn | 1434-1948 | |
| dc.description.abstractEn | The reaction of the Schiff-base like ligand H2L [L2- = (E,E)-({diethyl 2,2-[1,2-phenylenebis(iminomethylidyne)]bis(3-oxobutanato)})] with iron(II) acetate in methanol in the presence of 4-cyanopyridine leads to the formation of an octahedral iron(II) complex with the formula FeL(CNpy)2·0.25CNpy (1). The magnetic properties of this complex were investigated using temperature-dependent susceptibility measurements (SQUID) and Mössbauer spectroscopy. Both measurements indicate that the complex performs a stepwise spin transition with a large plateau in the region from 225 K to 125 K and HS 0.25. The molecule structure of the compound was determined at room temperature, 240 K (HS 0.5 according to susceptibility measurements) and 100 K. Two complex molecules were found in the asymmetric unit with strong - interactions between the phenylene rings of H2L. In agreement with outcomes from the magnetic measurements, both iron centres are in the high-spin state at room temperature and in the low-spin state at 100 K. At 240 K one of the two iron centres is high-spin and the other one low-spin. The reason for the wide step with one fourth of the iron centres in the high-spin state is the additional distorted 4-cyanopyridine in the crystal that influences the transition temperature of the surrounding iron centres. The spin transition was followed in solution by using 1H NMR spectroscopy. A gradual spin transition with T1/2 = 238 K is obtained. Temperature-dependent diffuse reflectivity spectra show the occurrence of photoconversion at the surface of the sample but only about 6 % of the complex could be switched in bulk condition using a SQUID magnetometer and the stability of the photoinduced HS state with TLIESST = 40 K is very weak. | |
| dc.language.iso | en | |
| dc.publisher | Wiley-VCH Verlag | |
| dc.title.en | Stepwise spin transition in a mononuclear iron(II) complex with unusually wide plateau | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1002/ejic.200701216 | |
| dc.subject.hal | Chimie/Matériaux | |
| bordeaux.journal | European Journal of Inorganic Chemistry | |
| bordeaux.page | 1589-1598 | |
| bordeaux.issue | 10 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00295165 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Internationale | |
| dc.subject.it | Iron | |
| dc.subject.it | Magnetic properties | |
| dc.subject.it | Spin crossover | |
| dc.subject.it | Photomagnetism | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00295165v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=European%20Journal%20of%20Inorganic%20Chemistry&rft.date=2008&rft.issue=10&rft.spage=1589-1598&rft.epage=1589-1598&rft.eissn=1434-1948&rft.issn=1434-1948&rft.au=WEBER,%20Birgit&CARBONERA,%20Chiara&DESPLANCHES,%20C%C3%A9dric&L%C3%89TARD,%20Jean-Fran%C3%A7ois&rft.genre=article |
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