Synthesis, crystal structures, and magnetic properties of cyano-bridged heterobimetallic chains based on [(Tp)Fe(CN)3]-

With the use of the tailored cyanometalate precursor, (Bu4N)[(Tp)Fe(CN)3] (Tp = Tris(pyrazolyl)hydroborate) as the building block to react with fully solvated Cu(II), Co(II), and Ni(II) cations, four one-dimensional (1D) heterobimetallic cyano-bridged chain complexes of squares, [(Tp)2Fe(III)2(CN)6Cu(CH3OH).2CH3OH]n (1), [(Tp)2Fe(III)2(CN)6Cu(DMF).DMF]n (2), [(Tp)2Fe(III)2(CN)6M(CH3OH)2.2CH3OH]n (M = Co (3) and Ni (4)), have been prepared. In complexes 1 and 2, the Cu(II) ions are pentacoordinated in the form of a slightly distorted square-based pyramid, and they are linked by distorted octahedrons of [(Tp)Fe(CN)3]- to form 1D chains of squares. In complexes 3 and 4, both the central Co(II) and Ni(II) ions have a slightly distorted octahedral coordination geometry, and they are bridged by [(Tp)Fe(CN)3]- to form similar 1D chains of squares. There are weak interchain pi-pi stacking interactions through the pyrazolyl groups of the Tp ligands for complexes 3 and 4. The crystal structures and magnetic studies demonstrate that complexes 1 and 2 exhibit intrachain ferromagnetic coupling and single-chain magnets behavior, and the blocking temperature is ca. 6 K for complex 1 and ca. 3 K for complex 2. Complexes 3 and 4 show significant metamagnetic behavior, where the cyanides mediate the intrachain ferromagnetic coupling between Fe(III) and Co(II) or Ni(II) ions and the interchain pi-pi stacking interactions lead to antiferromagnetic couplings. The field dependence of the magnetization measurements shows that the critical field is around 1 kOe for complex 3 and 0.8 kOe for complex 4 at 1.8 K.     

Syntheses,crystal structures and magnetic properties of two cyano-bridged two-dimensional assemblies [Fe(salpn)]2 [Fe(CN)5NO] and [Fe(salpn)]2[Ni(CN)4]

Two cyano-bridged assemblies, [Fe^III(salpn)]₂[Fe^II(CN)₅NO] (1) and [Fe^III (salpn)]₂[Ni^II(CN)₄] (2) [salpn = N, N-1,2-propylenebis(salicylideneiminato)dianion], have been prepared and structurally and magnetically characterized. In each complex, [Fe(CN)₅NO]^2– or [Ni(CN)₄]^2– coordinates with four [Fe(salpn)]⁺ cations using four co-planar CN^– ligands, whereas each [Fe(salpn)]⁺ links two [Fe(CN)₅NO]^2– or [Ni(CN)₄]^2– ions in the trans form, which results in a two-dimensional (2D) network consisting of pillow-like octanuclear [—M^II—CN—Fe^III—NC—]₄ units (M = Fe or Ni). In complex (1), the NO group of [Fe(CN)₅NO]^2– remains monodentate and the bond angle of Fe^II—N—O is 180.0°. The variable temperature magnetic susceptibilities, measured in the 5–300 K range, show weak intralayer antiferromagnetic interactions in both complexes with the intramolecular iron(III)iron(III) exchange integrals of –0.017 cm^–1 for (1) and –0.020 cm^–1 for (2), respectively.     

Syntheses, structures, and magnetic properties of low-dimensional heterometallic complexes based on the versatile building block [(Tp)Cr(CN)3]-

Using the tricyano precursor (Bu(4)N)[(Tp)Cr(CN)(3)] (Bu(4)N(+) = tetrabutylammonium cation; Tp = tris(pyrazolyl)hydroborate), a pentanuclear heterometallic cluster [(Tp)(2)Cr(2)(CN)(6)Cu(3)(Me(3)tacn)(3)][(Tp)Cr(CN)(3)](ClO(4))(3)·5H(2)O (1, Me(3)tacn = N,N',N'-trimethyl-1,4,7-triazacyclononane), three tetranuclear heterometallic clusters [(Tp)(2)Cr(2)(CN)(6)Cu(2)(L(OEt))(2)]·2.5CH(3)CN (2, L(OEt) = [(Cp)Co(P(O)(OEt)(2))(3)], Cp = cyclopentadiene), [(Tp)(2)Cr(2)(CN)(6)Mn(2)(L(OEt))(2)]·4H(2)O (3), and [(Tp)(2)Cr(2)(CN)(6)Mn(2)(phen)(4)](ClO(4))(2) (4, phen = phenanthroline), and a one-dimensional (1D) chain polymer [(Tp)(2)Cr(2)(CN)(6)Mn(bpy)](n) (5, bpy = 2,2'-bipyridine) have been synthesized and structurally characterized. Complex 1 shows a trigonal bipyramidal geometry in which [(Tp)Cr(CN)(3)](-) units occupy the apical positions and are linked through cyanide to [Cu(Me(3)tacn)](2+) units situated in the equatorial plane. Complexes 2-4 show similar square structures, where Cr(III) and M(II) (M = Cu(II) or Mn(II)) ions are alternatively located on the rectangle corners. Complex 5 consists of a 4,2-ribbon-like bimetallic chain. Ferromagnetic interactions between Cr(III) and Cu(II) ions bridged by cyanides are observed in complexes 1 and 2. Antiferromagnetic interactions are presented between Cr(III) and Mn(II) ions bridged by cyanides in complexes 3-5. Complex 5 shows metamagnetic behavior with a critical field of about 22.5 kOe at 1.8 K.     

Fe(bpb)(CN)2]- as a versatile building block for the design of novel low-dimensional heterobimetallic systems: synthesis, crystal structures, and magnetic properties of cyano-bridged Fe(III)-Ni(II) complexes [(bpb)(2-) = 1,2-bis(pyridine-2-carboxamido)benzenate

A dicyano-containing [Fe(bpb)(CN)2]- building block has been employed for the synthesis of cyano-bridged heterometallic Ni(II)-Fe(III) complexes. The presence of steric bpb(2-) ligand around the iron ion results in the formation of low-dimensional species: five are neutral NiFe2 trimers and three are one-dimensional (1D). The structure of the 1D complexes consists of alternating [NiL]2+ and [Fe(bpb)(CN)2]- generating a cyano-bridged cationic polymeric chain and the perchlorate as the counteranion. In all complexes, the coordination geometry of the nickel ions is approximately octahedral with the cyano nitrogen atoms at the trans positions. Magnetic studies of seven complexes show the presence of ferromagnetic interaction between the metal ions through the cyano bridges. Variable temperature magnetic susceptibility investigations of the trimeric complexes yield the following J(NiFe) values (based on the spin exchange Hamiltonian H = -2J(NiFe) S(Ni) (S(Fe(1)) + S(Fe(2))): J(NiFe) = 6.40(5), 7.8(1), 8.9(2), and 6.03(4) cm(-1), respectively. The study of the magneto-structural correlation reveals that the cyanide-bridging bond angle is related to the strength of magnetic exchange coupling: the larger the Ni-N[triple bond]C bond angle, the stronger the Ni- - -Fe magnetic interaction. One 1D complex exhibits long-range antiferromagnetic ordering with T(N) = 3.5 K. Below T(N) (1.82 K), a metamagnetic behavior was observed with the critical field of approximately 6 kOe. The present research shows that the [Fe(bpb)(CN)2]- building block is a good candidate for the construction of low-dimensional magnetic materials.     

Syntheses,crystal structures and magnetic properties of two new cyano-bridged bimetallic complexes

Transition Metal Chemistry - Two complexes [Fe(1,10-phen)2Ni(CN)4]n (1), {[Fe2(1,10-phen)4(CN)4Co2(1,10-phen)2Fe(CN)6]·2H2O}n (2) were prepared in the reaction of K3[Fe(CN)6] as cyanometalate...     

mer-[Fe III(bpca)(CN)3]-: a new low-spin iron(III) complex to build heterometallic ladder-like chains

The novel mononuclear complex PPh(4)-mer-[Fe(III)(bpca)(3)(CN)(3)].H(2)O (1) [PPh(4)(+) = tetraphenylphosphonium cation and bpca = bis(2-pyridylcarbonyl)amidate anion] and ladder-like chain compound [[Fe(III)(bpca)(micro-CN)(3)Mn(II)(H(2)O)(3)] [Fe(III)(bpca)(CN)(3)]].3H(2)O (2) have been prepared and characterized by X-ray diffraction analysis. Compound 1 is a low-spin iron(III) compound with three cyanide ligands in mer arrangement and a tridentate N-donor ligand building a distorted octahedral environment around the iron atom. Compound 2 is an ionic salt made up of cationic ladder-like chains [[Fe(III)(bpca)(micro-CN)(3)Mn(II)(H(2)O)(3)]](+) and uncoordinated anions [Fe(III)(bpca)(3)(CN)(3)](-). The magnetic properties of 2 correspond to those of a ferrimagnetic chain with significant intrachain antiferromagnetic coupling between the low-spin iron(III) centers and the high-spin manganese(II) cations. This compound exhibits ferrimagnetic ordering below 2.0 K.     

Chiral cyanide-bridged Cr(III)-Mn(III) heterobimetallic chains based on [(Tp)Cr(CN)3]-: synthesis, structures, and magnetic properties

By the reactions of Mn(III) Schiff-base complexes with the tricyanometalate building block, [(Tp)Cr(CN)(3)](-) (Tp = Tris(pyrazolyl) hydroborate), two couples of enantiomerically pure chiral cyano-bridged heterobimetallic one-dimensional (1D) chain complexes, [Mn((R,R)-Salcy)Cr(Tp)(CN)(3)·1/4H(2)O·1/2CH(2)Cl(2)](n) (1) and [Mn((S,S)-Salcy)Cr(Tp)(CN)(3)·1/4H(2)O·1/2CH(2)Cl(2)](n) (2) (Salcy = N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion), [Mn((R,R)-Salphen)Cr(Tp)(CN)(3)](n) (3) and [Mn((S,S)-Salphen)Cr(Tp)(CN)(3)](n) (4) (Salphen = N,N'-1,2-diphenylethylene-bis(salicylideneiminato) dianion), have been successfully synthesized. Circular dichroism (CD) spectra confirm the enantiomeric nature of the optically active complexes. Structural analyses reveal the formation of neutral cyano-bridged zigzag single chains in 1 and 2, and neutral cyano-bridged zigzag double chains in 3 and 4. Magnetic studies show that antiferromagnetic couplings are operative between Cr(III) and Mn(III) centers bridged by cyanide. Complexes 1 and 2 are the rare examples of chiral ferrimagnets; while complexes 3 and 4 exhibit a coexistence of chirality and spin-glass behavior in a 1D chain.     

Three K[M(salen)(CN)2]-based trinuclear sandwich-like heterobimetallic M(III)–Cu(II) (M = Fe,Cr, Co) complexes: synthesis,crystal structures,and magnetic properties

Transition Metal Chemistry - Three trans-dicyanoiron(III) precursors K[M(salen)(CN)2] (M = Fe, Cr or Co; H2salen = N,N′-bis(salicyl)ethylenediamine) and...     

Bimetallic cyanide-bridged complexes based on the photochromic nitroprusside anion and paramagnetic metal complexes. Syntheses, structures, and physical characterization of the coordination compounds [Ni(en)2]4[Fe(CN)5NO]2[Fe(CN)6]x5H2O, [Ni(en)2][Fe(CN)5NO]x3H2O, [Mn(3-MeOsalen)(H2O)]2[Fe(CN)5NO], and [Mn(5-Brsalen)]2[Fe(CN)5NO

The synthesis, crystal structure, and physical characterization of the coordination compounds [Ni(en)2]4[Fe(CN)5NO]2[Fe(CN)6]x5H2O (1), [Ni(en)2][Fe(CN)5NO]x3H2O (2), [Mn(3-MeOsalen)(H2O)]2[Fe(CN)5NO] (3), and [Mn(5-Brsalen)]2[Fe(CN)5NO] (4) are presented. 1 crystallizes in the monoclinic space group P2(1)/n (a = 7.407(4) A, b = 28.963(6) A, c = 14.744(5) A, alpha = 90 degrees, beta = 103.26(4) degrees, gamma = 90 degrees, Z = 2). Its structure consists of branched linear chains formed by cis-[Ni(en)2]2+ cations and ferrocyanide and nitroprusside anions. The presence of two kinds of iron(II) sites has been demonstrated by M?ssbauer spectroscopy. 2 crystallizes in the monoclinic space group P2(1)/c (a = 11.076(3) A, b = 10.983(2) A, c = 17.018(5) A, alpha = 90 degrees, beta = 107.25(2) degrees, gamma = 90 degrees, Z = 4). Its structure consists of zigzag chains formed by an alternated array of cis-[Ni(en)2]2+ cations and nitroprusside anions. 3 crystallizes in the triclinic space group P1 (a = 8.896(5) A, b = 10.430(5) A, c = 12.699(5) A, alpha = 71.110(5) degrees, beta = 79.990(5) degrees, gamma = 89.470(5) degrees, Z = 1). Its structure comprises neutral trinuclear bimetallic complexes in which a central [Fe(CN)5NO]2- anion is linked to two [Mn(3-MeOsalen)]+ cations. 4 crystallizes in the tetragonal space group P4/ncc (a = 13.630(5) A, c = 21.420(8) A, Z = 4). Its structure shows an extended 2D neutral network formed by cyclic octameric [-Mn-NC-Fe-CN-]4 units. The magnetic properties of these compounds indicate the presence of quasi-isolated paramagnetic Ni2+ and Mn3+. Irradiated samples of the four compounds have been studied by differential scanning calorimetry to detect the existence of the long-lived metastable states of nitroprusside.     

Cyanide-limited complexation of molybdenum(III): synthesis of octahedral [Mo(CN)(6)](3-) and cyano-bridged [Mo(2)(CN)(11)](5-)

Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature moment of mu(eff) = 3.80 mu(B), and assignment of its absorption bands leads to the ligand field parameters Delta(o) = 24800 cm(-1) and B = 247 cm(-1). Further restricting the available cyanide in a reaction between Mo(CF(3)SO(3))(3) and (Et(4)N)CN in DMF, followed by recrystallization from DMF/MeOH, yields (Et(4)N)(5)[Mo(2)(CN)(11)] x 2DMF x 2MeOH (2). The dinuclear [Mo(2)(CN)(11)](5-) complex featured therein contains two octahedrally coordinated Mo(III) centers spanned by a bridging cyanide ligand. A fit to the magnetic susceptibility data for 2, gives J = -113 cm(-1) and g = 2.33, representing the strongest antiferromagnetic coupling yet observed through a cyanide bridge. Efforts to incorporate these new complexes in magnetic Prussian blue-type solids are ongoing.     

Oxidation of linear trinuclear ruthenium complexes [Ru(3)(dpa)(4)Cl(2)] and [Ru(3)(dpa)(4)(CN)(2)]: synthesis, structures, electrochemical and magnetic properties

The neutral, monocationic, and dicationic linear trinuclear ruthenium compounds [Ru(3)(dpa)(4)(CN)(2)], [Ru(3)(dpa)(4)(CN)(2)][BF(4)], [Ru(3)(dpa)(4)Cl(2)][BF(4)], and [Ru(3)(dpa)(4)Cl(2)][BF(4)](2) (dpa=the anion of dipyridylamine) have been synthesized and characterized by various spectroscopic techniques. Cyclic voltammetric and spectroelectrochemical studies on the neutral and oxidized compounds are reported. These compounds undergo three successive metal-centered one-electron-transfer processes. X-ray structural studies reveal a symmetrical Ru(3) unit for these compounds. While the metal--metal bond lengths change only slightly, the metal--axial ligand lengths exhibit a significant decrease upon oxidation of the neutral complex. The electronic configuration of the Ru(3) unit changes as the axial chloride ligands are replaced by the stronger "pi-acid" cyanide axial ligands. Magnetic measurements and (1)H NMR spectra indicate that [Ru(3)(dpa)(4)Cl(2)] and [Ru(3)(dpa)(4)Cl(2)][BF(4)](2) are in a spin state of S=0 and [Ru(3)(dpa)(4)Cl(2)][BF(4)], [Ru(3)(dpa)(4)(CN)(2)], and [Ru(3)(dpa)(4)(CN)(2)][BF(4)] are in spin states of S=1/2, 1, and 3/2, respectively. These results are consistent with molecular orbital (MO) calculations.     

两个基于[Fe(bpca)(CN)3]-的一维3d-4f异金属配合物的合成和晶体结构

以[(bpca)Fe(CN)3]-(bpca=二(2-吡啶羰基)酰胺阴离子)为构筑基元,设计合成了2个新颖的3d-4f异金属配合物,{[(bpca)Fe(CN)3Pr(H2O)5]Cl2}n(1)和{[(bpca)2Fe2(CN)6Pr(H2O)6]Cl·4H2O}n(2),并测定了它们的晶体结构.化合物1的晶体属正交晶系,Pnma空间群;而化合物2属三斜晶系,P1空间群.在这2个化合物中,[(bpca)Fe(CN)3]-和[Pr(H2O)x]3 (1,x=5;2,x=6)交替排列形成一维链状结构,并通过π-π堆积作用、氢键作用及分子间短距离相互作用形成三维网络结构.     

Electronic structure and molecular properties of the heptacyanorhenate [Re(CN)7]3- and [Re(CN)7]4- complexes

We report scalar relativistic and Dirac scattered wave (DSW) calculations on the heptacyanorhenate [Re(CN)7](3-) and Re(CN)7(4-) complexes. Both the ground and lowest excited states of each complex split by spin-orbit interaction by about 0.3 eV. The calculated molecular electronegativities chi indicate that the open-shell complex is less reactive than the closed-shell complex, in agreement with experimental observations. The calculations indicate that the ground state spin density is highly anisotropic and that spin-orbit effects are responsible for the magnetic anisotropy of the molecular g tensor of the Re(CN)7(3-) complex. The calculated optical electronic transitions for both complexes with a polarizable continuum model using a time-dependent density functional (TDDFT)/B3LYP formalism are in reasonable agreement with those observed in the absorption spectrum.     

Syntheses, structures, and magnetic properties of the face-centered cubic clusters [Tp(8)(H(2)O)(12)M(6)Fe(8)(CN)(24)](4+) (M = Co, Ni)

Reactions between K[TpFe(CN)3] (Tp- = hydrotris(1-pyrazolyl)borate) and M(ClO4)2 x 6H2O (M = Co or Ni) in a mixture of acetonitrile and methanol afford, upon crystallization via THF vapor diffusion, [Tp8(H2O)12Co6Fe8(CN)24](ClO4)4.12THF x 7H2O (1) and [Tp8(H2O)12Ni6Fe8(CN)24](ClO4)4.12THF x 7H2O (2). Both compounds contain cyano-bridged clusters with a face-centered cubic geometry, wherein octahedral CoII or NiII centers are situated at the face-centering sites. The results of variable-temperature magnetic susceptibility measurements indicate the presence of ferromagnetic exchange coupling within both molecules to give ground states of S = 7 and 10, respectively. Low-temperature magnetization data reveal significant zero-field splitting, with the best fits for the Co6Fe8 and Ni6Fe8 clusters yielding D = -0.54 and 0.21 cm-1, respectively; ac magnetic susceptibility measurements performed on both samples showed no evidence of the slow relaxation effects associated with single-molecule magnet behavior.     

New cyanide-bridged Mn(III)-M(III) heterometallic dinuclear complexes constructed from [M(III)(AA)(CN)4]- building blocks (M = Cr and Fe): synthesis, crystal structures and magnetic properties

Three Mn(III)-M(III) (M = Cr and Fe) dinuclear complexes have been obtained by assembling [Mn(III)(SB)(H(2)O)](+) and [M(III)(AA)(CN)(4)](-) ions, where SB is the dianion of the Schiff-base resulting from the condensation of 3-methoxysalicylaldehyde with ethylenediamine (3-MeOsalen(2-)) or 1,2-cyclohexanediamine (3-MeOsalcyen(2-)): [Mn(3-MeOsalen)(H(2)O)(μ-NC)Cr(bipy)(CN)(3)]·2H(2)O (1), [Mn(3-MeOsalen)(H(2)O)(μ-NC)Cr(ampy)(CN)(3)][Mn(3-MeOsalen)(H(2)O)(2)]ClO(4)·2H(2)O (2) and [Mn(3-MeOsalcyen)(H(2)O)(μ-NC)Fe(bpym)(CN)(3)]·3H(2)O (3) (bipy = 2,2'-bipyridine, ampy = 2-aminomethylpyridine and bpym = 2,2'-bipyrimidine). The [M(AA)(CN)(4)](-) unit in 1-3 acts as a monodentate ligand towards the manganese(III) ion through one of its four cyanide groups. The manganese(III) ion in 1-3 exhibits an elongated octahedral stereochemistry with the tetradentate SB building the equatorial plane and a water molecule and a cyanide-nitrogen atom filling the axial positions. Remarkably, the neutral mononuclear complex [Mn(3-MeOsalen)(H(2)O)(2)]ClO(4) co-crystallizes with the heterobimetallic unit in 2. The values of the Mn(III)-M(III) distance across the bridging cyanide are 5.228 (1), 5.505 (2) and 5.265 ? (3). The packing of the neutral heterobimetallic units in the crystal is governed by the self-complementarity of the [Mn(SB)(H(2)O)](+) moieties, which interact each other through hydrogen bonds established between the aqua ligand from one fragment with the set of phenolate- and methoxy-oxygens from the adjacent one. The magnetic properties of the three complexes have been investigated in the temperature range 1.9-300 K. Weak antiferromagnetic interactions between the Mn(III) and M(III) ions across the cyanido bridge were found: J(MnM) = -5.6 (1), -0.63 (2) and -2.4 cm(-1) (3) the Hamiltonian being defined as H = -JS(Mn)·S(M). Theoretical calculations based on density functional theory (DFT) have been used to substantiate both the nature and magnitude of the exchange interactions observed and also to analyze the dependence of the magnetic coupling on the structural parameters within the Mn(III)-N-C-M(III) motif in 1-3.     

M(III)(bpym)(CN)(4)](-): a suitable building block to design ferrimagnetic cyano-bridged heterobimetallic chains (M = Fe, Cr; bpym = 2,2'-bypyrimidine)

Two cyano-bridged M(III)Mn(III) [M = Fe () and Cr ()] ferrimagnetic chains are reported; exhibits metamagnetism with two critical fields of 1250 G and 2.0 T which correspond to the overcoming by the applied dc field of the inter- and intrachain magnetic interactions, respectively.     

Photoinduced magnetization of the cyano-bridged 3d-4f heterobimetallic assembly Nd(DMF)(4)(H(2)O)(3)(micro-CN)Fe(CN)(5).H(2)O (DMF = N,N-dimethylformamide)

Photoinduced magnetization of the cyano-bridged 3d-4f heterobimetallic assembly Nd(DMF)4(H2O)3(mu-CN)Fe(CN)5.H2O (1) (DMF = N,N-dimethylformamide) is described in this paper. The chiMT values are enhanced by about 45% after UV light illumination in the temperature range of 5-50 K. We propose that UV light illumination induces a structural distortion in 1. This small structural change is propagated by molecular interactions in the inorganic network. Furthermore, the cooperativity resulting from the molecular interaction functions to increase the activation energy of the relaxation processes, which makes observation of the photoexcited state possible. The flexible network structure through the hydrogen bonds in 1 plays an essential role for the photoinduced phenomenon. This finding may open up a new domain for developing the molecule-based magnetic materials.     

Magnetic anisotropy of [Mo(CN)7]4- anions and fragments of cyano-bridged magnetic networks

Quantum chemistry calculations of CASSCF/CASPT2 level together with ligand field analysis are used for the investigation of magnetic anisotropy of [Mo(CN)7]4- complexes. We have considered three types of heptacyano environments: two ideal geometries, a pentagonal bipyramid and a capped trigonal prism, and the heptacyanomolybdate fragment of the cyano-bridged magnetic network K2[Mn(H2O)2]3[Mo(CN)7]2.6H2O. At all geometries the first excited Kramers doublet is found remarkably close to the ground one due to a small orbital energy gap in the ligand field spectrum, which ranges between a maximal value in the capped trigonal prism (800 cm(-1)) and zero in the pentagonal bipyramid. The small value of this gap explains (i) the axial form of the g tensor and (ii) the strong magnetic anisotropy even in strongly distorted complexes. Comparison with available experimental data for the g tensor of the mononuclear precursors reveals good agreement with the present calculations for the capped trigonal prismatic complex and a significant discrepancy for the pentagonal bipyramidal one. The calculations for the heptacyanomolybdate fragment of K2[Mn(H2O)2]3[Mo(CN)7]2.6H2O give g(perpendicular)/g(parallel) approximately 0.5 and the orientation of the local anisotropy axis close to the symmetry axis of an idealized pentagonal bipyramid. These findings are expected to be important for the understanding of the magnetism of anisotropic Mo(III)-Mn(II) cyano-bridged networks based on the [Mo(CN)7]4- building block.     

A linear single-molecule magnet based on [Ru(III)(CN)6]3-

We report the synthesis, structure and magnetic properties of the first molecular cluster and single-molecule magnet to incorporate [Ru(III)(CN)(6)](3-). Frequency-domain Fourier-transform THz-EPR (FDFT THz-EPR) and magnetic susceptibility measurements indicate strongly anisotropic Mn-Ru exchange interactions.     

2D LnIII RuIII 2 compounds constructed from trans-[Ru(acac)2(CN)2]-. Syntheses, structures, and magnetic properties

A series of cyano-bridged Ln(III)Ru(III)2 coordination polymers, Ph4P{Ln(NO3)2[Ru(acac)2(CN)2]2} [Ln = Tb (1), Dy (2), Er (3), Gd (4); Hacac = acetylacetone] have been synthesized by the reaction of Ln(NO3)3 with trans-Ph4P[Ru(acac)2(CN)2] in methanol. X-ray crystallographic determination reveals that these compounds are isostructural and have a wavy (4,4) layer structure with the Ln3+ ions bridged by trans-[Ru(acac)2(CN)2]-. Magnetic studies shows that the magnetic coupling between the Ln(III) and Ru(III) ions through the cyano bridges in 1-4 is negligibly weak.