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Synthesis, Crystal Structures, and Properties of Ni(NCS) 2 ‐4‐methoxypyridine Coordination Compounds
Author(s) -
Jochim Aleksej,
Ceglarska Magdalena,
Rams Michał,
Näther Christian
Publication year - 2018
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201800332
Subject(s) - differential scanning calorimetry , antiferromagnetism , crystallography , chemistry , thermogravimetry , octahedron , thermal decomposition , thiocyanate , potassium thiocyanate , powder diffraction , differential thermal analysis , crystal structure , single crystal , inorganic chemistry , diffraction , thermodynamics , organic chemistry , physics , condensed matter physics , optics
Two polymorphs of Ni(NCS) 2 (4‐methoxypyridine) 4 ( 1‐I , 1‐II ) as well as compounds with the compositions Ni(NCS) 2 (4‐methoxypyridine) 4 (MeCN) 1.33 ( 1‐MeCN ), Ni(NCS) 2 (4‐methoxypyridine) 2 (MeCN) 2 ( 2 ) and [Ni(NCS) 2 (4‐methoxypyridine) 2 ] n ( 3 ) are reported. For 1‐II no single crystals were obtained, but this compound is isotypic to the Fe analog 1‐II‐Fe . The crystal structures of 1 and 2 show discrete octahedral Ni II complexes, whereas in 3 the cations are connected by pairs of thiocyanate anions into chains. Solvent mediated conversion experiments reveal that 1‐I is thermodynamically stable at room temperature and differential scanning calorimetry shows no indication for a polymorphic transition. The thermal behavior of 1‐I , 1‐II , and 2 was investigated by simultaneous thermogravimetry and differential scanning calorimetry, which shows that they decompose in two discrete steps. In the first step compound 3 is formed as an intermediate, which decomposes on further heating into Ni(NCS) 2 . Time dependent XRPD investigations prove, that 2 transforms already at room temperature into 3 . Upon heating 1‐MeCN transforms into 1‐I in the first TG step, which decomposes on further heating into 3 . Investigation of the magnetic behavior of 3 shows dominating ferromagnetic exchange interactions along the chains with J = 5.9(1) K. Susceptibility measurements indicate antiferromagnetic ordering, which was confirmed by specific heat measurements, revealing that magnetic ordering occurs at 1.91(5) K.