A water sensitive ferromagnetic [Ni(cyclam)]₂[Nb(CN)₈] network

Abstract

Reaction between [Ni(cyclam)](2+) and [W(CN)(8)](4-) leads to the formation of a 3D diamond-like network [Ni(cyclam)](2)[W(CN)(8)]·3.5H(2)O (1). The structure is characterised by a network of intersecting channels of 3-4 Å in diameter, filled with crystallisation water, most of which is released upon drying in air, causing the crystals to collapse. Analogous compound [Ni(cyclam)](2)[Nb(CN)(8)]·3.5H(2)O (2), based on paramagnetic Nb(IV), could only be obtained as a powder, due to the decomposition of the [Nb(CN)(8)](4-) complex under slow diffusion conditions. It shows long-range magnetic ordering with T(C) = 11.8 K and magnetic hysteresis at 2 K. These properties are lost upon drying in air. After rehydration differently shaped hysteresis appears, which together with AC susceptibility measurements suggests the formation of a multiphase system. Subsequent dehydration-rehydration experiments show partial reversibility.

Solvatomagnetic Studies on Cyano‐Bridged Bimetallic Chains Based on [Mn(cyclam)]3+ and Hexacyanometallates

“…The most interesting solvatomagnetic effect, however, was observed for the {(H 3 O)[Ni(cyclam)][Fe(CN) 6 ] · 5H 2 O} n alternating bimetallic chain, partial dehydration of which causes reversible charge transfer in the unusual Ni III –Fe II redox couple . Similar, albeit less pronounced, structural flexibility has also been observed in the 3D {[Ni(cyclam)] 2 [Nb(CN) 8 ] · n H 2 O} n network . We have attributed these effects to the properties of the linear cationic building block, which allows bendability of trans ‐CN bridges and affords only weak intermolecular interactions through peripheral aliphatic groups of the relatively small cyclam ligand, and thus facilitates adaptation of the structure to the incoming guest molecules.…”

Larger pores and higher Tc: {[Ni(cyclam)]3[W(CN)8]2·solv}n – a new member of the largest family of pseudo-polymorphic isomers among octacyanometallate-based assemblies

“…We have earlier characterised two structurally dynamic networks based on the Ni-cyclam complex and octacyanometallates: {ijNiIJcyclam)] 3 ijWIJCN) 8 ] 2 } n (1) 3,4 and {[NiIJcyclam)] 2 ijNbIJCN) 8 ]} n , 5 both of which show long-range magnetic ordering. The magnetic changes accompanying dehydration of the Ni-NbIJIV) network proved to be only partially reversible.…”

Manganese‐Octacyanidoniobate‐Based Ferrimagnet Possessing Bridging Ligands with Disulfide Bonds

“…[47,[58][59][60][61][62] Among the organic ligands used in octacyanidometallate-based magnets showing long-range magnetic ordering, the dpds ligand is significantly large in size (Table 4). [61,[108][109][110][111] Although the dpds ligand is bulky, it fits in the cyanido-bridged MnÀ Nb framework due to its bend shaped induced by the disulfide bond. Thus, dpds ligands can be Table 2.…”