Cobalt(II) octacyanotungstate(V) organic-inorganic hybrid ferromagnetic materials with pyrazine and 4,4'-bipyridine.

Two new ferromagnetic organic-inorganic hybrid materials [Co(II)3(H2O)6(pyz)3[W(V)(CN)8]2].3.5H2O (1) and [Co(II)3(H2O)4(4,4'-bpy)3[W(V)(CN)8]2].1.5(4,4'-bpy).6H2O (2) have been synthesised and characterised. The structure of the compounds have been investigated combining EXAFS (extended X-ray absorption fine structure), ES-MS (electrospray mass spectrometry), IR (infrared spectroscopy), UV-VIS electronic spectroscopy and TGA (thermogravimetric analysis) coupled with QMS (quadrupole mass spectrometer) experiments. The studies reveal that both compounds consist of Co(II)-NC-W(V) and Co(II)-L-Co(II) linkages (L = pyrazine (1) or 4,4-bipyridine (2)). Both networks are created by cyano-bridged Co(II)3W(V)2 chains joined by organic linkers into a 2D architecture. A difference of cobalt coordination numbers in both compounds derived from EXAFS study is consistent with the ES-MS conclusion. The ac magnetic characterisation exhibits the transition to the ferromagnetic phase at T(C) = 26 K (1) and to the spin glass-like phase at T(G) = 16 K (2). The frequency dependent chi'(T) and chi''(T) signals indicate the presence of some disorder in spin alignment below ordering temperatures. Both networks are also characterised a by magnetic hysteresis loop of coercive field H(c) = 750 Oe (1) and 1200 Oe (2) at T = 4.2 K.

[1]  H. Goodwin.  Spin Crossover in Cobalt(II) Systems , 2005 .

[2]  M Newville,et al.  ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. , 2005, Journal of synchrotron radiation.

[3]  X. You,et al.  Octacyanometallate-based single-molecule magnets: Co(II)9M(V)6 (M = W, Mo). , 2005, Journal of the American Chemical Society.

[4]  O. Stéphan,et al.  Photomagnetic nanorods of the Mo(CN)8Cu2 coordination network. , 2005, Chemical communications.

[5]  R. Doedens,et al.  Inorganic−Organic Hybrid Materials Containing Porous Frameworks: Synthesis, Characterization, and Magnetic Properties of the Open Framework Solids [{Co(4,4‘-Bipy)}V2O6] and [{Co2(4,4‘-Bipy)3(H2O)2}V4O12]·2H2O , 2004 .

[6]  Gang Li,et al.  New types of the flexible self-assembled metal-organic coordination polymers constructed by aliphatic dicarboxylates and rigid bidentate nitrogen ligands. , 2004, Dalton transactions.

[7]  J. Marrot,et al.  Reversible photoinduced magnetic properties in the heptanuclear complex [Mo(IV)(CN)(2)(CN--CuL)(6)](8+): a photomagnetic high-spin molecule. , 2004, Angewandte Chemie.

[8]  A. Fletcher,et al.  Adsorption of gases and vapors on nanoporous Ni2(4,4'-Bipyridine)3(NO3)4 metal-organic framework materials templated with methanol and ethanol: structural effects in adsorption kinetics. , 2004, Journal of the American Chemical Society.

[9]  K. Stadnicka,et al.  Grid-type two-dimensional magnetic multinuclear metal complex: strands of ([CuII(mu-4,4'-bpy)]2+)n cross-linked by octacyanotungstate(V) ions. , 2004, Inorganic chemistry.

[10]  L. Long,et al.  A well-resolved uudd cyclic water tetramer in the crystal host of [Cu(adipate)(4,4-bipyridine)].(H2O)2. , 2004, Inorganic chemistry.

[11]  M. Rams,et al.  Crystal structures and magnetic properties of two low-dimensional materials constructed from [Mn(III)(salen)H2O]+ and [M(CN)8](3-/4-) (M = Mo or W) precursors. , 2004, Inorganic chemistry.

[12]  K. Dunbar,et al.  New Types of Layered and Pillared Layered Metal Carboxylate-Phosphonates Based on the 4,4‘-Bipyridine Ligand , 2004 .

[13]  K. Hashimoto,et al.  Manganese(II) o ctacyanotungstate(V)-based magnet containing a noncoordinated aromatic molecule. , 2004, Journal of the American Chemical Society.

[14]  K. Hashimoto,et al.  Two-dimensional metamagnet composed of cyano-bridged CuII-WV bimetallic assembly. , 2003, Chemical communications.

[15]  F. Lloret,et al.  Crystal structures and magnetic properties of two octacyanotungstate(IV) and (V)-cobalt(II) three-dimensional bimetallic frameworks. , 2003, Inorganic chemistry.

[16]  J. Sutter,et al.  Octadecanuclear Cluster or 1D Polymer with [{ML}2Nb(CN)8]n Motifs as a Function of {ML} (M = Ni(II), n = 6; M = Mn(II), n = ∞; L = Macrocycle) , 2003 .

[17]  Song Gao,et al.  Coexistence of long-range ferromagnetic ordering and glassy behavior in one-dimensional bimetallic cyano-bridged polymers. , 2003, Inorganic chemistry.

[18]  K. Stadnicka,et al.  Coordination polymers based on octacyanometalates(IV,V)(M = Mo, W) and aliphatic polyamine copper(II) tectons with [N3] donor atom sets , 2003 .

[19]  Song Gao,et al.  Synthesis, crystal structure and magnetic properties of a CuII–WV/IV bimetallic complex with a novel open framework structure , 2003 .

[20]  K. Hashimoto,et al.  Photoinduced magnetization in a two-dimensional cobalt octacyanotungstate. , 2003, Journal of the American Chemical Society.

[21]  C. Janiak.  Engineering coordination polymers towards applications , 2003 .

[22]  R. Clérac,et al.  Crystal Structures and Intercalation Reactions of Three‐Dimensional Coordination Polymers [M(H2O)2]2[Mo(CN)8]·4H2O (M = Co, Mn) , 2003 .

[23]  Song Gao,et al.  [Cu(tn)]3[W(CN)8]2·3H2O and [Cu(pn)]3[W(CN)8]2·3H2O: Two Novel Cu(II)−W(V) Cyano-Bridged Two-Dimensional Coordination Polymers with Metamagnetism , 2003 .

[24]  M. Zaworotko,et al.  A 3D metal-organic network, [Cu2(glutarate)2(4,4'-bipyridine)], that exhibits single-crystal to single-crystal dehydration and rehydration. , 2003, Chemical communications.

[25]  K. Hashimoto,et al.  Synthesis, crystal structures, and magnetic properties of two cyano-bridged tungstate(V)-manganese(II) bimetallic magnets. , 2003, Inorganic chemistry.

[26]  B. Sieklucka,et al.  Self-assembly of tetranuclear {[Co(trien)]2[W(CN)8]2}2− or {[Co(tren)]2[W(CN)8]2}2− squares with alternating aliphatic tetramine Co(III) and octacyanotungstate(IV) corners , 2003 .

[27]  Susumu Kitagawa,et al.  Porous coordination-polymer crystals with gated channels specific for supercritical gases. , 2003, Angewandte Chemie.

[28]  F. Lloret,et al.  [MnII2(bpym)(H2O)8]4+ and [MIV(CN)8]4−(M = Mo and W) as building blocks in designing bpym- and cyanide-bridged bimetallic three-dimensional networks (bpym = 2,2′-bipyrimidine) , 2003 .

[29]  H. Stoeckli-Evans,et al.  High-spin molecules: synthesis, X-ray characterization, and magnetic behavior of two new cyano-bridged Ni(II)(9)Mo(V)(6) and Ni(II)(9)W(V)(6) clusters with a S = 12 ground state. , 2002, Inorganic chemistry.

[30]  J. Pasán,et al.  The flexibility of molecular components as a suitable tool in designing extended magnetic systems , 2002 .

[31]  K. Hashimoto,et al.  Crystal Structure and Magnetic Properties of Two-dimensional Cyanide-bridged Bimetallic Assembly Composed of CsI[MnII(3-cyanopyridine)2{WV(CN)8}]·H2O , 2002 .

[32]  N. Alcock,et al.  2-D soft ferromagnet based on [Wv(CN)8]3- and CuII with a Tc of 34 K. , 2002, Chemical communications.

[33]  W. Wernsdorfer,et al.  Pentanuclear octacyanotungstate(V)-based molecule with a high spin ground state S= (13/2). , 2002, Inorganic chemistry.

[34]  M. Yamashita,et al.  Framework engineering by anions and porous functionalities of Cu(II)/4,4'-bpy coordination polymers. , 2002, Journal of the American Chemical Society.

[35]  Chuande Wu,et al.  A three-dimensional zeolite-like organic-inorganic hybrid material constructed from (CuMo2O8N)n double helical chains linked via [Cu(4,4'-bpy)]n fragments. , 2002, Chemical communications.

[36]  C. Mathonière,et al.  Structural and photo-induced magnetic properties of MII2[WIV(CN)8].xH2O (M = Fe and X = 8, Cu and x = 5). Comparison with CuII2[MoIV(CN)8].7.5H2O , 2001 .

[37]  K. Hashimoto,et al.  Photo-induced magnetization in copper(II) octacyanomolybdate(IV) , 2001 .

[38]  K. Hashimoto,et al.  Photo-magnetic and magneto-optical effects of functionalized metal polycyanides , 2001 .

[39]  Song Gao,et al.  One-dimensional coordination polymers [Co(acac)2pz]n and [Co(acac)2(4,4′-bipy)]n (acac=acetylacetone, pz=pyrazine, bipy=4,4′-bipyridine): synthesis, structures and magnetic properties , 2001 .

[40]  K. Hashimoto,et al.  Visible Light-Induced Reversible Photomagnetism in Copper(II) Octacyanomolybdate(IV) , 2001 .

[41]  C. Mathonière,et al.  Structural and photomagnetic studies of two compounds in the system Cu(2+)/Mo(CN8)(4-): from trinuclear molecule to infinite network. , 2001, Inorganic chemistry.

[42]  K. Hashimoto,et al.  Crystal structure and magnetic properties of an octacyanometalate-based three-dimensional tungstate(V)-manganese(II) bimetallic assembly. , 2000, Inorganic chemistry.

[43]  A. Katz,et al.  Bipyridine: the most widely used ligand. A review of molecules comprising at least two 2,2'-bipyridine units. , 2000, Chemical reviews.

[44]  M. Pilkington,et al.  High-Spin Molecules: A Novel Cyano-Bridged MnMo Molecular Cluster with aS=51/2 Ground State and Ferromagnetic Intercluster Ordering at Low Temperatures , 2000 .

[45]  A. Fujishima,et al.  A High-Spin Cyanide-Bridged Mn9W6 Cluster (S = 39/2) with a Full-Capped Cubane Structure , 2000 .

[46]  A. Jacobson,et al.  One-Dimensional Coordination Polymers of Cobalt with 4,4'-Bipyridine: Syntheses and Structures. , 1998, Inorganic chemistry.

[47]  Jian Lu,et al.  Coordination Polymers of Co(NCS)2 with Pyrazine and 4,4‘-Bipyridine: Syntheses and Structures , 1997 .

[48]  J. Contreras,et al.  Coordination Compounds of 4,4′-Bipyridyl with Copper(I) Halides , 1987 .

[49]  Robert C. Thompson,et al.  Low-dimensional magnetic exchange in the [iron] pyrazine-bridged complexes Fe(pyz)2(NCS)2 and Fe(pyz)(NCO)2 , 1987 .

[50]  Robert C. Thompson,et al.  Magnetic and spectroscopic study of pyrazine-bridged iron(II) halide complexes , 1986 .

[51]  M. Goldstein,et al.  Infrared and Raman spectra (3500-70 cm−1) and Mössbauer spectra of some pyrazine complexes of stannic halides , 1971 .

[52]  J. Ferraro,et al.  Transition Metal(II) Complexes of the Azines , 1969 .

[53]  C. Mathonière,et al.  Photomagnetism in Cyano-Bridged Hexanuclear Clusters [MnII(bpy)2]4[MIV(CN)8]2·xH2O (M = Mo, x = 14, and M = W, x = 9) , 2005 .

[54]  Song Gao,et al.  A novel Cu(II)-W(V) bimetallic assembly magnet {[Cu(en)2]3[W(CN)8]2·H2O}∞ (en = ethylenediamine) with cube-like W8Cu12 units from a coordinated anion template self-assembly reactionElectronic supplementary information (ESI) available: selected hydrogen bonding parameters in 1 (Table S1) and perspect , 2002 .

[55]  C. Mathonière,et al.  Structural and photomagnetic studies of a 1-D bimetallic chain [MnII2(L)2(H2O)][MoIV(CN)8]·5H2O (L = macrocycle): analogy with the photo-oxidation of K4[MoIV(CN)8]·2H2O , 2000 .

[56]  K. Biradha,et al.  Covalent and noncovalent interpenetrating planar networks in the crystal structure of {[Ni(4,4′-bipyridine)2(NO3)2·2pyrene}n , 1999 .

[57]  Xiao‐Ming Chen,et al.  A novel two-dimensional rectangular network. Synthesis and structure of {[Cu(4,4′-bpy)(pyz)(H2O)2][PF6]2}n (4,4′-bpy = 4,4′-bipyridine, pyz = pyrazine) , 1998 .

[58]  A. J. Blake,et al.  Rectangular grid two-dimensional sheets of copper(II) bridgedby both co-ordinated and hydrogen bonded 4,4′-bipyridine(4,4′-bipy) in[Cu(µ-4,4′-bipy)(H2O)2(FBF3)2]·4,4′-bipy , 1997 .

[59]  J. Zarembowitch.  ELECTRONIC SPIN CROSSOVERS IN SOLID-STATE MOLECULAR COMPOUNDS-SOME NEW ASPECTS CONCERNING COBALT(II) COMPLEXES , 1992 .

[60]  M. Goldstein,et al.  Infrared spectra, electronic spectra, and magnetic properties of dihalogenobis(pyrazine) complexes of cobalt(II) and nickel(II): a structural re-assignment , 1972 .

[61]  F. Miller,et al.  Infra-red and Raman spectra ot the diazines , 1957 .