Titelangaben
Lochenie, Charles ; Bauer, Wolfgang ; Railliet, Antoine P. ; Schlamp, Stephan ; Garcia, Yann ; Weber, Birgit:
Large Thermal Hysteresis for Iron(II) Spin Crossover Complexes with N-(Pyrid-4-yl)isonicotinamide.
In: Inorganic Chemistry.
Bd. 53
(2014)
Heft 21
.
- S. 11563-11572.
ISSN 1520-510X
DOI: https://doi.org/10.1021/ic501624b
Abstract
A new series of iron(II) 1D coordination polymers with the general formula [FeL1(pina)]·xsolvent with L1 being a tetradentate N2O22– coordinating Schiff-base-like ligand [([3,3′]-[1,2-phenylenebis(iminomethylidyne)]bis(2,4-pentanedionato)(2-)-N,N′,O2,O2′], and pina being a bridging axial ligand N-(pyrid-4-yl)isonicotinamide, are discussed. The X-ray crystal structure of [FeL1(pina)]·2MeOH was solved for the low-spin state. The compound crystallizes in the monoclinic space group P21/c, and the analysis of the crystal packing reveals the formation of a hydrogen bond network where additional methanol molecules are included. Different magnetic properties are observed for the seven samples analyzed, depending on the nature of the included solvent molecules. The widest hysteresis loop is observed for a fine crystalline sample of composition [FeL1(pina)]·xH2O/MeOH. The 88 K wide thermal hysteresis loop (T1/2↑ = 328 K and T1/2↓ = 240 K) is centered around room temperature and can be repeated without of a loss of the spin transition properties. For the single crystals of [FeL1(pina)]·2MeOH, a 51 K wide hysteresis loop is observed (T1/2↑ = 296 K and T1/2↓ = 245 K) that is also stable for several cycles. For a powder sample of [FeL1(pina)]·0.5H2O·0.5MeOH a cooperative spin transition with a 46 K wide hysteresis loop around room temperature is observed (T1/2↑ = 321 K and T1/2↓ = 275 K). This compound was further investigated using Mössbauer spectroscopy and DSC. Both methods reveal that, in the cooling mode, the spin transition is accompanied by a phase transition while in the heating mode a loss of the included methanol is observed that leads to a loss of the spin transition properties. These results show that the pina ligand was used successfully in a crystal-engineering-like approach to generate 1D coordination polymers and improve their spin crossover properties.
Weitere Angaben
Publikationsform: | Artikel in einer Zeitschrift |
---|---|
Begutachteter Beitrag: | Ja |
Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Professur Anorganische Chemie IV > Professur Anorganische Chemie IV - Univ.-Prof. Dr. Birgit Weber Fakultäten Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Professur Anorganische Chemie IV |
Titel an der UBT entstanden: | Ja |
Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
Eingestellt am: | 25 Jul 2017 12:46 |
Letzte Änderung: | 25 Jul 2017 12:46 |
URI: | https://eref.uni-bayreuth.de/id/eprint/38809 |