Auxiliary alkyl chain modulated spin crossover behaviour of [Fe(H2Bpz2)2(Cn-bipy)] complexes
| Autor: | Shufang Xue, Yann Garcia, Aurelian Rotaru, Helge Müller-Bunz, Grace G. Morgan, Shishen Zhang, Yunnan Guo |
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| Rok vydání: | 2021 |
| Předmět: |
Ligand field theory
chemistry.chemical_classification Materials science Spin states 010405 organic chemistry Transition temperature Spin transition 010402 general chemistry 01 natural sciences 0104 chemical sciences Inorganic Chemistry Bipyridine chemistry.chemical_compound Crystallography chemistry Spin crossover Soft matter Alkyl |
| Zdroj: | Dalton Transactions. 50:12835-12842 |
| ISSN: | 1477-9234 1477-9226 |
| DOI: | 10.1039/d1dt01787j |
| Popis: | Three new alkyl chain substituted complexes [Fe(H2Bpz2)2(Cn-bipy)] (pz = pyrazolyl, Cn-bipy = bipyridine alkyl chain diester, n = 3 (3), 4 (4) and 5 (5)) show versatile spin state switching behaviour with different “tail” lengths as revealed by structural and magnetic analyses. The most striking phenomenon is observed for 5 which undergoes an abrupt spin transition accompanied by thermal hysteresis of ca. 10 K, which is attributed to crystal packing effects derived from the competition between π⋯π and C–H⋯O interactions. Interestingly, each of the complexes exhibits similar gradual and complete spin crossover in methanol solution with a transition temperature around 249 K, as deduced from temperature-dependent UV-vis spectroscopy. This highlights the differences between the solid state (ligand field; crystal packing) and solution (ligand field; solvation) effects on spin crossover. This work demonstrates that the length of the complex's alkyl chain substituents on the complex can have a large impact on the transition temperature and profile of solid state spin crossover, offering a potential path to the fabrication of soft matter spin crossover materials. |
| Databáze: | OpenAIRE |
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