期刊
INORGANIC CHEMISTRY
卷 59, 期 5, 页码 2843-2852出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.inorgchem.9b03170
关键词
-
资金
- Carl Zeiss Foundation
The dimeric motif is the smallest unit for two interacting spin centers allowing for systematic investigations of cooperative interactions. As spin transition compounds, dinuclear complexes are of particular interest, since they potentially reveal a two-step spin crossover (SCO), switching between the high spin- high spin [HS-HS], the high spin-low spin [HS-LS], and the low spin-low spin [LS-LS] states. Herein, we report the synthesis and characterization of six dinuclear iron(H) complexes [Fe-2(II)(mu(2)-L-1)(2)](BF4)(4) (C1), [Fe-2(II)(mu(2)-L-1)(2)](ClO4)(4) (C2), [Fe-2(II)(mu(2)-L-1)(2)](F3CSO3)(4) (C3), [Fe-2(II)(mu(2)-L-2)(2)](BF4)(4) (C4), [Fe-2(II)(mu(2)-L-2)(2)](BF4)(4) (C5), and [Fe-2(II)(mu(2)-L-2)(2)](BF4)(4) (C6), based on the 1,3,4-thiadiazole bridging motif. The two novel bistridentate ligands (L-1 = 2,5-bis{[(1H-imidazol-2-ylmethyl)amino]-methyl}-1,3,4-thiadiazole and L-2 = 2,5-bis{[(thiazol-2-ylmethyl)-amino]-methyl}-1,3,4-thiadiazole) were employed in the presence of iron(II) salts with the different counterions. Upon varying ligands and counterions, we were able to change the magnetic properties of the complexes from a temperatureindependent [HS-HS] spin state over a one-step spin transition toward a two-step SCO. When cooled slowly from room temperature, the two-step SCO goes along with two distinct phase transitions, and in the intermediate mixed [HS-LS] state distinct HS/LS pairs can be identified unambiguously. In contrast, rapid cooling precludes a crystallographically observable phase transition. For the mixed [HS-LS] state Mossbauer spectroscopy confirms a statistical (random) orientation of adjacent [HS-LS]center dot[HS-LS]center dot[HS-LS] chains.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据