 |
Journal articles
One-Dimensional Thiocyanato-Bridged Fe(II) Spin Crossover Cooperative Polymer With Unusual FeN5S Coordination Sphere
Abstract : We present here a novel example of spin crossover phenomenon on a Fe(II) one-dimensional chain with unusual N5S coordination sphere. The [{Fe(tpc-OMe)(NCS)(μ-NCS)}n] (1) compound was prepared using the tridentate tpc-OMe ligand (tpc-OMe = tris(2-pyridyl)methoxymethane), FeCl2·4H2O, and the KSCN salt. Crystallographic investigations revealed that the Fe(II) ions are connected by a single bridging NCS– ligand (μ-κN:κS-SCN coordination mode) to afford a zigzag neutral chain running along the [010] direction, in which the thiocyanato bridging groups adopt a cis head-to-tail configuration. The (N5S) metal environment arises from one thiocyanato-κS and two thiocyanato-κN ligands and from three pyridine of the fac-tpc-OMe tripodal ligand. This compound presents a unique extension of Fe(II) binuclear complexes into linear chains built on similar tripodal ligands and bridging thiocyanate anions. Compound 1 shows a spin crossover (SCO) behavior which has been evidenced by magnetic, calorimetric, and structural investigations, revealing a sharp cooperative spin transition with a transition temperature of ca. 199 K. Temperature scan rate studies revealed a very narrow hysteresis loop (∼1 K wide). Photoswitching of this compound was also performed, evidencing a very fast relaxation process at low temperature. Among other factors, the linearity of the N-bound terminal thiocyanato ligand appears as the main structural characteristic at the origin of the presence of the SCO transition in compound 1 and in the two others Fe(II) previous systems involving thiocyanato-bridges and tripodal tris(2-pyridyl)methane ligands.
Cited literature [61 references]
https://hal.univ-brest.fr/hal-01872926
Contributor : Nicolas Renard <>
Submitted on : Wednesday, September 12, 2018 - 4:29:34 PM
Last modification on : Monday, June 22, 2020 - 10:48:06 AM
Long-term archiving on: : Thursday, December 13, 2018 - 2:52:11 PM
Contributor : Nicolas Renard <>
Submitted on : Wednesday, September 12, 2018 - 4:29:34 PM
Last modification on : Monday, June 22, 2020 - 10:48:06 AM
Long-term archiving on: : Thursday, December 13, 2018 - 2:52:11 PM
File
One-Dimensional Thiocyanato-Br...
Files produced by the author(s)
Supporting Info : https://pubs.acs.org/doi/suppl/10.1021/acs.inorgchem.8b02061