Thermal Spin Crossover and LIESST Effect Observed in Complexes [Fe(LCh)2(NCX)2] [LCh = 2,5-Di(2-Pyridyl)-1,3,4-Chalcadiazole; Ch = O, S, Se; X = S, Se, BH
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- 作者：Julia Klingele ; Dominic Kaase ; Maximilian Schmucker ; Yanhua Lan ; Guillaume Chastanet ; Jean-Fran莽ois L茅tard
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：May 20, 2013
- 年：2013
- 卷：52
- 期：10
- 页码：6000-6010
- 全文大小：588K
- 年卷期：v.52,no.10(May 20, 2013)
- ISSN：1520-510X
文摘
Two new complexes belonging to the family [FeII(L)2(NCX)2] have been synthesized and structurally characterized. Complexation of the ligand LO = 2,5-di(2-pyridyl)-1,3,4-oxadiazole results in the formation of two derivatives of [FeII(LO)2(NCS)2] (1) with the common s-trans and the rarely observed s-cis conformation. No thermal spin crossover (SCO) was observed for the amorphous bulk material of the mixture. Using the new ligand LSe = 2,5-di(2-pyridyl)-1,3,4-selenadiazole, compound [FeII(LSe)2(NCS)2]路1.4DCM路0.6MeOH (2路1.4DCM路0.6MeOH) was structurally characterized by single crystal X-ray diffraction. Bulk material of [FeII(LSe)2(NCS)2]路MeOH (2路MeOH) exhibits a thermally induced SCO with small hysteresis [T1/2(鈫? = 91 K, T1/2(鈫? = 96 K]. LIESST and reflectivity studies have been performed on the SCO complexes [FeII(LS)2(NCS)2], [FeII(LS)2(NCSe)2], [FeII(LS)2(NCBH3)2]路H2O [LS = 2,5-di(2-pyridyl)-1,3,4-thiadiazole], and 2路MeOH. All complexes belong to the T0 = 90 K line [T(LIESST) = T0 鈥?0.3T1/2]. [FeII(LS)2(NCS)2], that exhibits a two-stepped thermal SCO process, has been found to also exhibit two well-separated T(LIESST) temperatures [T(LIESST, 1) = 44 K; T(LIESST, 2) = 53 K].