title: Influence of metal coordination and co-ligands on the magnetic properties of 1D Co(NCS)2coordination polymers.
abstract: Two new transition metal thiocyanate coordination polymers with the composition [Co(NCS)2(4-vinylpyridine)2]n(1) and [Co(NCS)2(4-benzoylpyridine)2]n(2) were synthesized and their crystal structures were determined. In both compounds the Co cations are octahedrally coordinated by two trans-coordinating 4-vinyl- or 4-benzoylpyridine co-ligands and four μ-1,3-bridging thiocyanato anions and linked into chains by the anionic ligands. While in 1 the N and the S atoms of the thiocyanate anions are also in trans-configuration, in 2 they are in cis-configuration. A detailed magnetic study showed that the intra-chain ferromagnetic coupling is slightly stronger for 2 than for 1, and that the chains in both compounds are weekly antiferromagnetically coupled. Both compounds show a long range magnetic ordering transition at Tc= 3.9 K for 1 and Tc= 3.7 K for 2, which is confirmed by specific heat measurements. They also show a metamagnetic transition at a critical field of 450 Oe (1) and 350 Oe (2), respectively. Below Tc1 and 2 exhibit magnetic relaxations resembling relaxations of single chains. The exchange constants obtained from magnetic and specific heat data are in good accordance with those obtained from constrained DFT calculations carried out on isolated model systems. The ab initio calculations allowed us to find the principal directions of anisotropy.
authors.affiliation: Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Rams
authors.affiliation: Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Tomkowicz
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Jena, Humboldtstr. 8, 07743 Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Böhme
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Jena, Humboldtstr. 8, 07743 Jena, Germany.
authors.forename: Winfried
authors.initials: W
authors.lastname: Plass
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany. cnaether@ac.uni-kiel.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Suckert
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany. cnaether@ac.uni-kiel.de.
authors.forename: Julia
authors.initials: J
authors.lastname: Werner
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany. cnaether@ac.uni-kiel.de.
authors.forename: Inke
authors.initials: I
authors.lastname: Jess
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany. cnaether@ac.uni-kiel.de.
authors.forename: Christian
authors.identifier: http://orcid.org/0000-0001-8741-6508
authors.initials: C
authors.lastname: Näther