A novel two-dimensional honeycomb-like bimetallic iron(III)–nickel(II) cyanide-bridged magnetic material [Ni(cyclam)]3[Fe(CN)6]2·nH2O(cyclam = 1,4,8,11-tetraazacyclodecane)

Abstract

The 2D honeycomb-like layered iron(iii)-nickel(ii) cyanidebridged complex [Ni(cyclam)] 3 [Fe(CN)6] 2 ·nH 2 O exhibits ferromagnetic intralayer and antiferromagnetic interlayer interactions; above 3 K the magnetic properties are typical of a metamagnet with H c = 5000 G, whereas below 3 K a canted structure is formed, leading to a long range ferromagnetic ordering.Bimetallic assemblies with Prussian blue-like structure form a family of materials that exhibit spontaneous magnetization at T c as high as 315 K, 1 and interesting electro-chemical, optoelectronic and magneto-optical properties. 2 The crystallization of Prussian blue analogues, however, is very difficult and it has been only quite recently that Kahn and coworkers 3 have succeeded in growing crystals of [Mn 2 (H 2 O) 5 Mo(CN) 7 ]·nH 2 O (a and b forms), which ferromagnetically order at 51 K.One alternative route to bimetallic cyanide-bridged extended arrays is that of using hexacyanometalate building blocks with metal complexes containing polydentate ligands. This hybrid approach favours the crystallization and then their magnetostructural study. Depending on the nature of the building blocks different and fascinating extended network structures can be obtained, some of which are magnetically ordered. 4 On O (n = 12 and 22.5). X-ray analysis † reveals that both phases exhibit similar structures, which only differ in the number of water molecules (hereafter we shall discuss the results for n = 22.5, whose structure is more accurately determined). The structure consists of honeycomb-like layers (Fig. 1) and crystal water molecules that occupy the interlayer space.

Synthesis, Crystal Structure, Magnetism, Band Structure and Density of States of [C6H18N3]ClCoCl4

“…Transition metal complexes of amines have been synthesized in order to investigate how the functional groups affect their coordination geometry and chemical properties [4,5]. This complex has become a very important building block of bridged complexes that possess various dimensional structures and fascinating magnetic properties [6][7][8][9].…”

Stoichiometric Control of the Magnetic Properties in Copper(II) Cyano‐Bridged Bimetallic Complexes

“…General Remarks: Compounds Cu(NO 3 ) 2 ·3H 2 O (Panreac), K 3 [Fe(CN) 6 ] (Fluka) and cis-chxn (Fluka) were of reagent grade and used without further purification.…”

“…[19] A solution of cis-chxn (228 mg, 2 mmol) in methanol (5 mL) was added dropwise to a stirred solution of Cu(NO 3 Magnetic Measurements: Variable-temperature susceptibility measurements were carried out on polycrystalline samples in the 2Ϫ300 K temperature range at magnetic fields of 1 T (1) and 0.1 T (2) using a magnetometer (Quantum Design MPMS-XL-5) equipped with a SQUID sensor. Diamagnetic contributions were corrected with Pascal's constants.…”

“…The sample, however, showed the presence of further disordered water molecules. Calculations with PLATON [25] indicated a solvent-accessible void centred around the inversion point (1/2, 1/2, 1/2) with an area of 73 Å 3 . There was some indication of electron density at this site.…”

“…However, not very many examples of these have been reported to date. Only two of such copper-containing compounds, [Cu(Et-OH) 2 ][Cu(en)] 2 [Cr(CN) 6 ] 2 (en ϭ 1,2-diaminoethane) [15] and [Cu(tn)] 3 [Cr(CN) 6 ] 2 ·3H 2 O (tn ϭ 1,3-diaminopropane), [18] have been structurally characterised and exhibit spontaneous magnetisation, with critical temperatures, T c , of 57 K and 9.5 K, respectively. To the best of our knowledge, no Cu II ϪFe III cyanide-bridged compounds showing magnetic ordering have been reported so far, as most of the Cu II ϪFe bimetallic systems are indeed formed by diamagnetic hexacyanoferrate(II) units.…”