Heterobimetallic cyanide-bridged FeIII(μ-CN)MII complexes (M = Mn and Cu): synthesis, structure and magnetism

Systematic magneto-structural studies reveal ‘[FeIII(Tp)(CN)2(μ-CN)MnIICl(L1/L2)]′ (both antiferromagnetic) and [FeIII(Tp)(CN)2(μ-CN)CuII(L1/L2)]+′(L1 ferro- and L2 antiferromagnetic).

Cyanido-bridged {FeIIILnIII} heterobimetallic chains assembled through the [FeIII{HB(pz)3}(CN)3]− complex as metalloligand: synthesis, crystal structure and magnetic properties

The first isostructural series of cyanido-bridged 3d–4f chains showing a unique zig-zag motif have been obtained by using the heteroleptic [Fe^III{HB(pz)₃}(CN)₃]⁻ complex as a metalloligand towards the preformed [Ln^III(bpdo)(NO₃)₂(H₂O)]⁺ species.

X-ray Structure and Magnetic Properties of Heterobimetallic Chains Based on the Use of an Octacyanidodicobalt(III) Complex as Metalloligand

The assembly of [Co2III(μ-2,5-dpp)(CN)8]2− anions and [MII(CH3OH)2(DMSO)2]2+ cations resulted into the formation of two heterobimetallic 1D coordination polymers of formula [MII(CH3OH)2(DMSO)2(μ-NC)2Co2III(μ-2,5-dpp)(CN)6]n·4nCH3OH [M = CoII (1)/FeII (2) and 2,5-dpp = 2,5-bis(2-pyridyl)pyrazine. The [Co2III(μ-2,5-dpp)(CN)8]2− metalloligand coordinates the paramagnetic [MII(CH3OH)2(DMSO)2]2+ complex cations, in a bis-monodentate fashion, to give rise to neutral heterobimetallic chains. Cryomagnetic dc (1.9–300 K) and ac (2.0–13 K) magnetic measurements for 1 and 2 show the presence of Co(II)HS (1) and Fe(II)HS (2) ions (HS – high-spin), respectively, with D values of +53.7(5) (1) and −5.1(3) cm−1 (2) and slow magnetic relaxation for 1, this compound being a new example of SIM with transversal magnetic anisotropy. Low-temperature Q-band EPR study of 1 confirms that D value is positive, which reveals the occurrence of a strong asymmetry in the g-tensors and allows a rough estimation of the E/D ratio, whereas 2 is EPR silent. Theoretical calculations by CASSCF/NEVPT2 on 1 and 2 support the results from magnetometry and EPR. The analysis of the ac magnetic measurements of 1 shows that the relaxation of M takes place in the ground state under external magnetic dc fields through dominant Raman and direct spin-phonon processes.

In situ generation of Ph3PO in cyanido-bridged heterometallic {FeIIILnIII}2 molecular squares (Ln = Eu, Sm)

Two new examples of cyanido-bridged {Fe^IIILn^III}₂ molecular squares, with pyim and PPh₃O as capping ligands at the Ln^III sites, exhibit weak antiferromagnetic interactions [Ln = Eu (1), Sm (2), pyim = 2-(1H-imidazol-2-yl)pyridine, PPh₃PO = triphenylphosphine oxide].

A novel octacyanido dicobalt(iii) building block for the construction of heterometallic compounds

The first bimetallic 3d cyanido-bearing complex with 2,5-dpp as a bridge, (Ph₄P)₂[Co₂^III(μ-2,5-dpp)(CN)₈]·2H₂O, is obtained and used as a metalloligand with the [Mn(MAC)(H₂O)₂]²⁺ cation to build a {Co^IIIMn^II} heterobimetallic chain.

Design of 3d–4f molecular squares through the [Fe{(HB(pz)3)}(CN)3]− metalloligand

A new series of cyanido-bridged {FeIII2LnIII2} heterobimetallic molecular squares [Ln = La (1), Gd (2), Tb (3) and Dy (4)] has been prepared and magneto-structurally investigated.

{CoIIIMnIII}ncorrugated chains based on heteroleptic cyanido metalloligands

The use of cyanide-bearing complexes affords one-dimensional coordination polymers with the formulas {[Mn^III(salen)(μ-NC)₂Co^III(4,4-dmbipy)(CN)₂]·H₂O}_n(1) and {[Mn^III(salen)(μ-NC)₂Co^III(dmphen)(CN)₂]}_n(2) .

Towards a better understanding of honeycomb alternating magnetic networks

The honeycomb mixed-ligand complex {[Co₂(bpm)(ox)₂]_n·5nH₂O} was prepared and magneto-structurally characterized. The values of the antiferromagnetic interactions through bpm (J_bpm= −5.0 cm⁻¹) and ox (J_ox= −11.1 cm⁻¹) ligands obtained by fit were suported by DFT type calculations.

Assembly of cyanometalate-functionalized phosphotungstates with magnetic properties and bifunctional electrocatalytic activities

Two cyanometalate-functionalized Dawson type phosphotungstates with a “Netherlands windmills” shape have been prepared under conventional reaction conditions. Their magnetic properties and electrocatalytic activity were investigated.

Oxamato-based coordination polymers: recent advances in multifunctional magnetic materials

The design and synthesis of novel examples of multifunctional magnetic materials based on the so-called coordination polymers (CPs) have become very attractive for chemists and physicists due to their potential applications in nanoscience and nanotechnology.

Syntheses, crystal structures, MMCT and magnetic properties of four one-dimensional cyanide-bridged complexes comprised of MII–CN–FeIII (M = Fe, Ru, Os)

Four 1D cyanide-bridged complexes [cis-M^II(L)₂(CN)₂Fe^III(salen)](PF₆) (3–6) have been synthesized, of which 3 and 4 are Class II mixed-valence complexes.

Two-dimensional coordination polymers constructed by [Ni(II)Ln(III)] nodes and [W(IV)(bpy)(CN)6]2- spacers: a network of [Ni(II)Dy(III)] single molecule magnets

Three isomorphous two-dimensional (2D) coordination polymers of general formula {[Ni(II)(valpn)Ln(III)(NO3)(H2O)(μ-NC)4W(IV)(bipy)(CN)2]·xH2O·yCH3CN}n have been synthesized by reacting Ph4P[W(V)(CN)6(bipy)] with the heterodinuclear [Ni(II)Ln(III)(valpn)(O2NO)3] complexes [H2valpn = 1,3-propanediyl-bis(2-iminomethylene-6-methoxyphenol), bipy = 2,2'-bipyridine, and Ln = Gd (1), Dy (2), and Tb (3) with x = 2 (1), 3.9 (2), and 3.35 (3) and y = 2.50 (1), 2 (2), and 1.8 (3)]. Their crystal structures consist of [Ni(II)Ln(III)] 3d-4f nodes which are connected by [W(IV)(bipy)(CN)6](2-) diamagnetic linkers resulting from the reduction of W(V) to W(IV) during the reaction process. The Ni(II) and Ln(III) ions occupy the inner and outer coordination sites of the dideprotonated valpn ligand, respectively, and they are doubly bridged by the phenoxo oxygen atoms of such a ligand. The value of Ni(II)···Ln(III) separation through this bridge is 3.4919(10) (1), 3.4760(10) (2), and 3.4799(9) (3) Å, and those of the angles at the bridgehead phenoxo atoms are 106.6(2) and 107.3(2) (1), 106.9(2), and 107.8(2) (2) and 106.5(2)-106.8(2)° (3). Each W(IV) is eight-coordinated with a bidentate bipy molecule and six cyanide-carbon atoms building a somewhat distorted square antiprism environment. The rare-earth cations are nine-coordinated, the donor atoms describing a monocapped square antiprism for 1 and 3 and a tricapped trigonal prism for 2. Magnetic susceptibility measurements in the temperature range 1.9-300 K show the occurrence of ferromagnetic interactions between the Ni(II) and Ln(III) ions in 1-3. Frequency-dependent alternating susceptibility signals were observed for the Dy(III) derivative below 8.0 K under an applied dc field of 2500 G indicating the presence of slow magnetic relaxation with values of the pre-exponential factor (τ0) and energy barrier (E(#)) of ca. 5.7 × 10(-8) s and 15.9 cm(-1), respectively. Complex 2 constitutes the first example of a 2D 3d-4f heterobimetallic single molecule magnet (SMM).