Structural, magnetic and photomagnetic study of the [Fe(PM–NEA)2(NCS)2] spin crossover complex
Langue
en
Article de revue
Ce document a été publié dans
Comptes Rendus. Chimie. 2008, vol. 11, n° 10, p. 1155-1165
Académie des sciences (Paris)
Résumé en anglais
The new spin-crossover compound [Fe(PM–NEA)2(NCS)2] with PM–NEA = N-(2-pyridylmethylene)-4-(naphthalene-1-ethynyl)aniline has been synthesized. The temperature dependence of χMT (χM = molar magnetic susceptibility and T = ...Lire la suite >
The new spin-crossover compound [Fe(PM–NEA)2(NCS)2] with PM–NEA = N-(2-pyridylmethylene)-4-(naphthalene-1-ethynyl)aniline has been synthesized. The temperature dependence of χMT (χM = molar magnetic susceptibility and T = temperature) has revealed a very gradual complete spin conversion between LS (S = 0) and HS (S = 2) states with T1/2 of about 204 K. At 10 K the well-known LIESST (light-induced excited spin state trapping) effect has been observed within the SQUID cavity, by irradiating a powder sample with a Kr+ laser coupled with an optical fibre. The HS → LS relaxation after LIESST has been analyzed with a stretched exponential behaviour. This is consistent with structural analysis, since the presence of naphthalene rings induces a less compact crystal packing than in already reported [Fe(PM–L)2(NCS)2] crystal structures. In particular, the intermolecular interaction network shows a noteworthy dissymmetry on each side of the complex. Furthermore, the structure–property relationship confirms the important role of the metal coordination sphere distortion on the T1/2 value.< Réduire
Mots clés en anglais
Coordination chemistry
Iron(II) metal ions
Spin crossover
X-ray diffraction
Photomagnetism
Structure–property relationship
Phase transition
Origine
Importé de halUnités de recherche