@Article{D0DT03227A,
author ="Jochim, Aleksej and Rams, Michał and Böhme, Michael and Ceglarska, Magdalena and Plass, Winfried and Näther, Christian",
title  ="Thermodynamically metastable chain and stable layered Co(NCS)2 coordination polymers: thermodynamic relations and magnetic properties",
journal  ="Dalton Trans.",
year  ="2020",
pages  ="-",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/D0DT03227A",
url  ="http://dx.doi.org/10.1039/D0DT03227A",
abstract  ="Reaction of Co(NCS)2 with 4-bromopyridine leads to the formation of discrete complexes with the composition Co(NCS)2(4-bromopyridine)4·(CH3CN)0.67 (1){,} Co(NCS)2(4-bromopyridine)2(H2O)2 (2){,} Co(NCS)2(4-bromopyridine)2(CH3OH)2 (3) and Co(NCS)2(4-bromopyridine)2(CH3CN)2 (4). Upon heating compounds 2 and 4 transform into a crystalline product with the composition Co(NCS)2(4-bromopyridine)2 (5-I) that also can easily be obtained from solution. In this compound{,} the Co cations are linked by single μ-1{,}3-bridging thiocyanate anions into layers. Thermal decomposition of 3 leads to a second isomer (5-II){,} which is thermodynamically metastable and can also be synthesized from solution under kinetic control. In contrast to 5-I{,} the Co cations are linked by pairs of anionic ligands into linear chains. The magnetic exchange is very weak in 5-I{,} but much stronger and ferromagnetic along the linear chains in 5-II. AF ordering in 5-II is reached at 3.05 K{,} and magnetic relaxation is observed at the metamagnetic transition with an Arrhenius barrier of 17.1(3) cm−1. Ab initio computational studies reveal a different type of magnetic anisotropy to be present in the two crystallographically – independent Co centers in 5-II."}