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Dimorphic Modifications of the Thiocyanato‐Bridged Coordination Polymer [Ni(NCS) 2 (pyridazine)(H 2 O) 0.5 ] n with Different Magnetic Properties
Author(s) -
Wriedt Mario,
Näther Christian
Publication year - 2011
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201000846
Subject(s) - pyridazine , chemistry , crystallography , thiocyanate , antiferromagnetism , crystal structure , paramagnetism , hydrogen bond , octahedron , magnetic susceptibility , coordination polymer , magnetism , molecule , inorganic chemistry , stereochemistry , physics , organic chemistry , quantum mechanics , condensed matter physics
Reaction of nickel(II) thiocyanate with pyridazine under hydrothermal conditions leads to the formation of the hemihydrate [Ni(NCS) 2 (pyridazine)(H 2 O) 0.5 ] n ( 1I ). The crystal structure was determined by X‐ray single‐crystal structure analysis. In the crystal structure two types of Ni II cations are found. Both are coordinated by one μ‐1,1‐NCS‐ and two μ‐1,3‐NCS‐bridging thiocyanato anions as well as two μ‐1,2‐bridging pyridazine ligands. The octahedral coordination sphere of Ni1 is completed by one coordinating water molecule and that of Ni2 by one terminal N ‐bonded thiocyanato anion. These building blocks are connected into chains, which are further connected into a 2D polymeric network by strong interchain hydrogen bonding. By thermal decomposition of the precursor compound 1I , a new anhydrate [Ni(NCS) 2 (pyridazine)] n ( 2 ) is obtained. On rehydration, this compound transforms into a new polymorphic hemihydrate modification 1II . Magnetic measurements of both forms show completely different behavior: Whereas modification 1I shows a long‐range antiferromagnetic ordering state at T N = 5.4 K, modification 1II only shows Curie–Weiss paramagnetism with weak ferromagnetic interactions.