title: Dehydration of Octacyanido-Bridged NiII-WIVFramework toward Negative Thermal Expansion and Magneto-Colorimetric Switching.
abstract: An inorganic three-dimensional [NiII(H2O)2]2[WIV(CN)8]·4H2O (1) framework undergoes a single-crystal-to-single-crystal transformation upon thermal dehydration, producing a fully anhydrous phase NiII2[WIV(CN)8] (1d). The dehydration process induces changes in optical, magnetic, and thermal expansion properties. While 1 reveals typical positive thermal expansion of the crystal lattice, greenish-yellow color, and paramagnetic behavior, 1d is the first ever reported octacyanido-based solid revealing negative thermal expansion, also exhibiting a deep red color and diamagnetism. Such drastic shift in the physical properties is explained by the removal of water molecules, leaving the exclusively cyanido-bridged bimetallic network, which is accompanied by the transformation of the octahedral paramagnetic [NiII(H2O)2(NC)4]2-to the square-planar diamagnetic [NiII(NC)4]2-moieties.
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.|Department of Chemistry, School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Reczyński
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.|Department of Chemistry, School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Szymon
authors.initials: S
authors.lastname: Chorazy
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Nowicka
authors.affiliation: Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sieklucka
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Ohkoshi