دورية أكاديمية
Spin-Crossover in a New Iron(II)/Di(pyrazolyl)pyridine Complex with a Terpyridine Embrace Lattice. Thermally Induced Excited Spin State Trapping and Clarification of a Structure−Function Correlation
| العنوان: | Spin-Crossover in a New Iron(II)/Di(pyrazolyl)pyridine Complex with a Terpyridine Embrace Lattice. Thermally Induced Excited Spin State Trapping and Clarification of a Structure−Function Correlation |
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| المؤلفون: | Michaels, E, Capel Berdiell, I, Vasili, HB, Pask, CM, Howard, MJ, Cespedes, O, Halcrow, MA |
| بيانات النشر: | American Chemical Society |
| سنة النشر: | 2022 |
| المجموعة: | White Rose Research Online (Universities of Leeds, Sheffield & York) |
| الوصف: | The complex salts [FeL2]X2 (1X2; L = 2,6-di{4-fluoropyrazol-1-yl}pyridine; X– = BF4– or ClO4–) exhibit abrupt spin-transitions with narrow thermal hysteresis, at T1/2 = 164 K (X– = BF4–) and 148 K (X– = ClO4–). The transition in 1[ClO4]2 is complicated by efficient thermally induced excited spin-state trapping (TIESST) of its high-spin state below ca. 120 K, and the fully low-spin state was achieved only inside the magnetometer at a scan rate of 0.5 K min–1. Crystals of 1[BF4]2 are tetragonal (P421c, Z = 2; phase 1) at 300 K but transform to a highly twinned monoclinic phase 2 (P21, Z = 2) at 285 ± 5 K. These are forms of the “terpyridine embrace” crystal lattice, which often affords cooperative spin-transitions in iron/di(pyrazolyl)pyridine complexes. Phase 2 of high-spin 1[BF4]2 shows a significant temperature dependence by powder diffraction, which reflects increased canting of the monoclinic unit cell as the temperature is lowered. In contrast, 1[ClO4]2 retains phase 2 between 100 and 300 K, and was crystallographically characterized in its thermally trapped metastable high-spin state at 100 K, as well as its thermodynamic high- and low-spin forms at higher temperatures. The spin-crossover transition temperature in 1[ClO4]2 and related compounds correlates well with a parameter describing angular changes to the metal coordination sphere during the transition but not with other commonly used structural indices. The TIESST metastable high-spin state of 1[ClO4]2 shows no single molecule magnet properties at 2 K. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | text |
| اللغة: | English |
| العلاقة: | https://eprints.whiterose.ac.uk/191436/12/acs.cgd.2c00980.pdfTest; Michaels, E, Capel Berdiell, I, Vasili, HB et al. (4 more authors) (2022) Spin-Crossover in a New Iron(II)/Di(pyrazolyl)pyridine Complex with a Terpyridine Embrace Lattice. Thermally Induced Excited Spin State Trapping and Clarification of a Structure−Function Correlation. Crystal Growth and Design, 22 (11). pp. 6809-6817. ISSN 1528-7483 |
| الإتاحة: | https://eprints.whiterose.ac.uk/191436Test/ https://eprints.whiterose.ac.uk/191436/12/acs.cgd.2c00980.pdfTest |
| حقوق: | cc_by_4 |
| رقم الانضمام: | edsbas.5489C9D2 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |