Stabilization of Ni2+ dimers in hexacyano Mo6 cluster-based Prussian blue derivatives: experimental and theoretical investigations of magnetic properties

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 47; no. 4; pp. 1122 - 1130
• Main Authors: Daigre, Gilles, Costuas, Karine, Tarasenko, Maria S, Alexandra Yu Ledneva, Naumov, Nikolay G, Lemoine, Pierric, Guizouarn, Thierry, Molard, Yann, Amela-Cortes, Maria, Audebrand, Nathalie, Cordier, Stéphane
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2018
• Subjects: Ammonia; Antiferromagnetism; Cations; Chemical bonds; Chemical Sciences; Clusters; Coupling (molecular); Cristallography; Crystal structure; Crystals; Cubes; Cyanides; Diffusion rate; Dimers; Hydrogen atoms; Hydrogen bonds; Magnetic properties; Material chemistry; Molybdenum; Nickel compounds; Pigments; Single crystals; Ethylenediamine; Supramolecular Framework; Single-crystal Structure; Extended Framework; Cyanides; Divalent cation; Molybdenum; Clusters compounds
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt02748f

Herein, two new octahedral molybdenum cyanide cluster compounds, namely [{Ni(NH3)6}4{Ni2(NH3)8}1][Mo6Br6Q2(CN)6]3·12H2O, Q = S (1) and Se (2), have been synthesized as single crystals by slow diffusion of a solution of nickel chloride into aqueous ammonia solutions of a K2Cs2[Mo6Br6Q2(CN)6] molybdenum cyanide cluster-based compound. Both 1 and 2 were structurally characterized by single-crystal X-ray diffraction. They are isostructural and crystallize in the cubic system (Im3m (no. 229); Z = 2, a = 18.147(1) Å, and V = 5976(1) Å3 and a = 18.188(2) Å and V = 6016(2) Å3 for 1 and 2, respectively). 1 and 2 are based on the association of [Mo6Bri6Qi2(CN)a6]4− (Q = S, Se) cluster anions with Ni2+ dimer-based cubic [Ni2(NH3)8]4+ and octahedral [Ni(NH3)6]2+ cations. The structure is based on 2-fold interpenetrated [{Ni(NH3)6}4{Ni2(NH3)8}1][Mo6Br6Q2(CN)6]3 frameworks related to each other by [½, ½, ½] translation. The unit cell is based on a body-centered cubic framework of cubic [Ni2(NH3)8]4+. The [Mo6Bri6Qi2(CN)a6]4− (Q = S, Se) cluster units are located in the middle of the edges and at the center of the faces of the cell. The [{Ni(NH3)6}]2+ cations are located at the center of the cubes of the a/2 edge. The dimers [Ni2(NH3)8]4+ are stabilized by hydrogen bonds between the cyanide ligands of the cluster unit and the hydrogen atoms of the ammonia molecules. Both compounds exhibit a weak antiferromagnetic coupling within the [Ni2(NH3)8]4+ dimer entities at low temperatures together with a paramagnetic behavior originating from the cations of the octahedral [{Ni(NH3)6}]2+ complexes.