Cooperative Spin Crossover and Order-Disorder Phenomena in a Mononuclear Compound [Fe(DAPP)(abpt)](ClO4)2 [DAPP = [Bis(3-aminopropyl)(2-pyridylmethyl)amine], abpt = 4-Amino-3,5-b
详细信息 查看全文
- 作者：Galina S. Matouzenko ; Azzedine Bousseksou ; Serguei A. Borshch ; Monique Perrin ; Samir Zein ; Lionel Salmon ; Gabor Molnar ; and Sylvain Lecocq
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：January 12, 2004
- 年：2004
- 卷：43
- 期：1
- 页码：227 - 236
- 全文大小：177K
- 年卷期：v.43,no.1(January 12, 2004)
- ISSN：1520-510X
文摘
The synthesis and detailed characterization of the new spin crossover mononuclear complex [FeII(DAPP)(abpt)](ClO4)2, where DAPP = [bis(3-aminopropyl)(2-pyridylmethyl)amine] and abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole, are reported. Variable-temperature magnetic susceptibility measurements and Mössbauer spectroscopyhave revealed the occurrence of an abrupt spin transition with a hysteresis loop. The hysteresis width derived frommagnetic susceptibility measurements is 10 K, the transition being centered at Tc
= 171 K for decreasing and Tc
= 181 K for increasing temperatures. The crystal structure was resolved in the high-spin (293 and 183 K) andlow-spin (123 K) states. Both spin-state structures belong to the monoclinic space group P21/n (Z = 4). Thethermal spin transition is accompanied by the shortening of the mean Fe-N distances by 0.177 Å. The two mainstructural characteristics of [Fe(DAPP)(abpt)](ClO4)2 are a branched network of intermolecular links in the crystallattice and the occurrence of two types of order-disorder transitions (in the DAPP ligand and in the perchlorateanions) accompanying the thermal spin change. These features are discussed relative to the magnetic propertiesof the complex. The electronic structure calculations show that the structural disorder in the DAPP ligand modulatesthe energy gap between the HS and LS states. In line with previous studies, the order-disorder phenomena andthe spin transition in [Fe(DAPP)(abpt)](ClO4)2 are found to be interrelated.
= 171 K for decreasing and Tc= 181 K for increasing temperatures. The crystal structure was resolved in the high-spin (293 and 183 K) andlow-spin (123 K) states. Both spin-state structures belong to the monoclinic space group P21/n (Z = 4). Thethermal spin transition is accompanied by the shortening of the mean Fe-N distances by 0.177 Å. The two mainstructural characteristics of [Fe(DAPP)(abpt)](ClO4)2 are a branched network of intermolecular links in the crystallattice and the occurrence of two types of order-disorder transitions (in the DAPP ligand and in the perchlorateanions) accompanying the thermal spin change. These features are discussed relative to the magnetic propertiesof the complex. The electronic structure calculations show that the structural disorder in the DAPP ligand modulatesthe energy gap between the HS and LS states. In line with previous studies, the order-disorder phenomena andthe spin transition in [Fe(DAPP)(abpt)](ClO4)2 are found to be interrelated.