New Spin-Crossover Compounds Containing the [Ni(mnt)] Anion (mnt = Maleonitriledithiolate)

Magnetochemistry

Hiroki Akutsu¹  Joanna Daniell²  ScottS. Turner²  PeterN. Horton³  SimonJ. Coles³  Volker Schünemann⁴ 

[1] Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan;Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK;EPSRC National Crystallographic Service, School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, UK;Technische Universität Kaiserslautern, Erwin Schrödinger-Str 46, D-67663 Fachbereich Physik, Germany;

关键词: spin-crossover;    molecular magnets;    magnetic materials;    molecular materials;   

DOI  :  10.3390/magnetochemistry7050072

来源: DOAJ

【 摘 要 】

Two novel salts containing the anion [Ni(mnt)₂]⁻ (mnt = maleonitriledithiolate) have been synthesized. The counter-ions, [Fe(II)(L¹ or L²)₂], are cationic complexes where L¹ and L² are methylated derivatives of 2,6-bis(pyazolyl)pyridine or pyrazine, which are similar to ligands found in a series of spin-crossover (SCO) complexes. Both salts are characterized by variable temperature single crystal X-ray diffraction and bulk magnetization measurements. Compound 1, [Fe(II)(L¹)₂][Ni(mnt)₂]₂ displays an incomplete and gradual SCO up to 300 K, followed by a more rapid increase in the high-spin fraction between 300 and 350 K. Compound 2, [Fe(II)(L²)₂][Ni(mnt)₂]₂.MeNO₂, shows a gradual, but more complete SCO response centered at 250 K. For compound 2, the SCO is confirmed by variable temperature Mössbauer spectroscopy. In both cases, the anionic moieties are isolated from each other and so no electrical conductivity is observed.

【 授权许可】

Unknown