Coordination polymers of Mn2+ and Dy3+ ions built with a bent tricarboxylate: Metamagnetic and weak anti-ferromagnetic behavior (original) (raw)
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Structure and magnetism of coordination polymers containing dicyanamide and tricyanomethanide
2003
Coordination polymers containing dicyanamide (N(CN) 2 − , dca) or tricyanomethanide (C(CN) − 3 , tcm) bridging ligands are described from the perspective of their structure and magnetism. The binary compounds ␣-M(dca) 2 form an isostructural series (M = Cr, Mn, Fe, Co, Ni, Cu) having a single rutile-like network that involves 1,3,5 -dca bridging. They display quite diverse types of long-range magnetic order viz. canted-spin antiferromagnets (Cr, Mn, Fe), ferromagnets (Co, Ni, Cu). An up-to-date review is given of the diverse range of physical measurements made on the ␣-M(dca) 2 series together with interpretations for the different net exchange coupling and consequent 3D order. The doubly interpenetrating rutile network M(tcm) 2 series generally do not show long-range order except for a few members at very low temperatures. The 'mixed' self-penetrating network compounds M(dca)(tcm) do show long-range order (M = Co, Ni), albeit at lower T c values than for the M(dca) 2 parents. Modification of the M-dca networks is possible by incorporation of coligands into the structures. Ternary species of type M(dca) 2 (L) n , where L is a terminal (e.g. pyridine, MeOH) or a bridging (e.g. pyrazine, 4,4 -bipyridine) coligand, display a diverse range of 1D, 2D and 3D structural types. With a few exceptions, the large number of compounds structurally characterised contain 1,5 -dca bridging and display very weak antiferromagnetic coupling (J < ca. −1 cm −1 ), typical of this bridging mode. Compounds such as Mn(dca) 2 (pyrazine) display a magnetic phase transition at low temperatures. This is also the case in the isostructural 2D layer compounds M(dca) 2 (H 2 O) · phenazine (M = Fe, Ni) which, perhaps not surprisingly, do not have coordinated phenazines but, rather, phenazines intercalated between layers of M(dca) 2 (H 2 O) in which 1,3,5 and 1,5 -dca bridging exists. Anionic networks of types M(dca) − 3 and M(dca) 2− 4 formed by templation around cations of the organic (e.g. Ph 4 E + , R 4 N + ) or inorganic (M(2,2 -bipyridine) 2+ 3 ) types are described.
Synthesis, Structure, and Magnetic Behavior of Two New 1D Polymeric Manganese Azido Complexes
European Journal of Inorganic Chemistry, 2006
Two new MnII one-dimensional compounds with formulae [Mn(μ-N3)2(pyzamid)2]n (1) and [Mn2(3-ampy)4(μ-N3)2(N3)2(H2O)2]n, (2) (pyzamid = pyrazineamide and 3-ampy = 3-aminopyridine) were structurally and magnetically characterized. Compound 1 crystallizes in the monoclinic system, P2/c space group, and polymerizes through double end-on azido bridges giving 1D chains with the MnII atoms in a MnN6 environment. Compound 2 crystallizes in the triclinic system, P space group, and consists of alternate [Mn(3-ampy)2(μ-N3)2(N3)2] and [Mn(3-ampy)2(μ-N3)2(H2O)2] octahedrons (MnN6 – MnN4O2 environments), linked by single end-to-end azido bridges. Both chains show very uncommon topologies. Attemps to obtain manganese/azido derivatives with the qux = quinoline-4-carboxylato anion gave the recently reported compound [Mn(μ-qux)2(μ-H2O)]n (3), which consists of a chain with only carboxylato and aqua bridges with the MnII atoms in a MnO6 slightly distorted octahedron. In good agreement with the expected behavior, magnetic susceptibility measurements show weak ferromagnetic interactions for 1, whereas compound 2 exhibits moderate antiferromagnetic coupling.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Journal of Solid State Chemistry, 2001
The coordination polymers [M(dca) 2 pyz] (M ؍ Mn, Fe, Co, Ni, Zn) have been synthesized and characterized by singlecrystal and powder X-ray di4raction. Two isomers have been observed. The compounds contain two interpenetrating 3D -Po related networks. Bidentate dca ligands bridge the metal atoms to form square-grid-like M(dca) 2 sheets, with the pyrazine ligands linking these sheets together to form the -Po-like 3D networks. The compounds contain interdigitated 2D sheets. The sheets consist of 1D chains of M(dca) 2 connected together by the pyrazine ligands. The compounds display an interesting phase change that simultaneously induces twinning of the crystals. At room temperature the structures are orthorhombic Pnma and contain dynamic disorder of the dca ligands. However, on cooling (e.g., to 123 K) the structures become monoclinic P2 1 /n with the dca ligands ordered, but since domains within each crystal order di4erently, this results in pseudo-merohedral twinning. Variable temperature and variable 5eld magnetic studies have shown that these compounds display weak antiferromagnetic coupling between the high-spin metal centers. Only in the case of -[Mn(dca) 2 pyz] is there evidence for 3D antiferromagnetic order occurring below 2.7 K.
Polyhedron, 2013
Two new compounds [Mn(dca) 2 (dmdpy)] (1) and [Co(dca) 2 (dmdpy)] (2) (dca = dicyanamide and dmdpy = 5,5 0-dimethyl-2,2 0-dipyridine) were synthesized and characterized by single crystal X-ray diffraction, FTIR, thermal analysis and magnetic measurements. In both compounds, the dmdpy ligand adopts a bidentate chelating coordination mode while dca anions act as bidentate l 1,5 bridging ligand and the metal centers are involved in a distorted octahedral geometry. In compounds 1 and 2, dca ligands connect the metal sites giving rise to 1D and 2D coordination polymers, respectively. Weak antiferromagnetic interactions were observed between the metal centers in both compounds.
2000
By reaction of K 4 [Mo III (CN) 7 ]•2H 2 O, Mn(ClO 4) 2 •6H 2 O and bidentate chelating ligands, three new cyanobridged compounds, namely Mn 2 (3-pypz)(H 2 O)(CH 3 CN)[Mo(CN) 7 ] (1), Mn 2 (1-pypz)(H 2 O)(CH 3 CN)[Mo (CN) 7 ] (2) and Mn 2 (pyim)(H 2 O)(CH 3 CN)[Mo(CN) 7 ] (3) (3-pypz = 2-(1H-pyrazol-3-yl)pyridine, 1-pypz = 2-(1H-pyrazol-1-yl)pyridine, pyim = 2-(1H-imidazol-2-yl)pyridine), have been synthesized and characterized structurally and magnetically. Single crystal X-ray analyses revealed that although the chelating ligands are different, compounds 1 to 3 are isomorphous and crystallize in the same monoclinic space group C2/m. Connected by the bridging cyano groups, one crystallographically unique [Mo(CN) 7 ] 4− unit and three crystallographically unique Mn II ions of different coordination environments form similar threedimensional frameworks, which have a four-nodal 3,4,4,7-connecting topological net with a vertex symbol of {4 3 }{4 4 •6 2 } 2 {4 10 •6 11 }. Magnetic measurements revealed that compounds 1-3 display long-range magnetic ordering with critical temperatures of 64, 66 and 62 K, respectively. These compounds are rare examples of a small number of chelating co-ligand coordinated [Mo(CN) 7 ] 4−-based magnetic materials. Specifically, the bidentate chelating ligands were successfully introduced into the heptacyanomolybdate system for the first time. † Electronic supplementary information (ESI) available: Structure information in detail, powder XRD spectra, and additional magnetic figures. CCDC 1835917-1835919. For ESI and crystallographic data in CIF or other electronic format see
CrystEngComm, 2014
The reaction of M(ox)‚2H 2 O (M ) Co(II), Ni(II)) or K 2 (Cu(ox) 2 )‚2H 2 O (ox ) oxalate dianion) with n-ampy (n ) 2, 3, 4; n-ampy ) n-aminopyridine) and potassium oxalate monohydrate yields one-dimensional oxalatobridged metal(II) complexes which have been characterized by FT-IR spectroscopy, variable-temperature magnetic measurements, and X-ray diffraction methods. The complexes M(µ-ox)(2-ampy) 2 (M ) Co (1), Ni (2), Cu ) are isomorphous and crystallize in the monoclinic space group C2/c (No. 15), Z ) 4, with unit cell parameters for 1 of a ) 13.885(2) Å, b ) 11.010(2) Å, c ) 8.755(1) Å, and ) 94.21 , Ni (5), Cu ) are also isomorphous and crystallize in the orthorhombic space group Pcnn (No. 52), Z ) 8, with unit cell parameters for 6 of a ) 12.387 , b ) 12.935(3), and c ) 18.632(2) Å. Compound Co(µ-ox)(4-ampy) 2 (7) crystallizes in the space group C2/c (No. 15), Z ) 4, with unit cell parameters of a ) 16.478(3) Å, b ) 5.484(1) Å, c ) 16.592(2) Å, and ) 117.76(1)°. Complexes M(µ-ox)(4-ampy) 2 (M ) Ni (8), Cu (9)) crystallize in the orthorhombic space group Fddd (No. 70), Z ) 8, with unit cell parameters for 8 of a ) 5.342(1), b ) 17.078 , and c ) 29.469(4) Å. All compounds are comprised of one-dimensional chains in which M(n-ampy) 2 2+ units are sequentially bridged by bis-bidentate oxalato ligands with M‚‚‚M intrachain distances in the range of 5.34-5.66 Å. In all cases, the metal atoms are six-coordinated to four oxygen atoms, belonging to two bridging oxalato ligands, and the endo-cyclic nitrogen atoms, from two n-ampy ligands, building distorted octahedral surroundings. The aromatic bases are bound to the metal atom in cis (1-6) or trans (7-9) positions. Magnetic susceptibility measurements in the temperature range of 2-300 K show the occurrence of antiferromagnetic intrachain interactions except for the compound 3 in which a weak ferromagnetic coupling is observed. Compound 7 shows spontaneous magnetization below 8 K, which corresponds to the presence of spin canted antiferromagnetism.
ID manganese(III) and iron(III) coordination polymers containing Schiff-base ligands and dicyanamide
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 2003
The I D coordinati on polymers, [MIII(Schiff-base)(dca)]", dca-= di cyanamide, N(CN h-, M'" = Mn and Fe, Schiff-base= salen 2 • (N.N'-eth ylenebis(sali cy laldiminato» (1) and (2); sal-o-phen 2-(N, N'-o-phenylenebis (sali cylaldim in ato» (3) and (4); (±)-saltch 2-(N,N'-(±)-trans-cyclohexanebis (sal icy laldiminato» (5) and (6), are reported. The complexes consist of octahedral hi gh-spin Mill ato ms coordi nated in the equatori al plane by the tetra-chelating Schiff-base li gand and coordinated in the axial positions by sin gle ~1 .5-dic y anam id e bridges, forming infinite linear zi gzag chains. The chains of co mplexes 1 to 6 interd igitate in a parallel fashion with adjacent chains, via weak IT-stacking. Variable temperature magnetic susceptibility measurements (2-300 K; H = I T) have shown that these compounds display very weak anti ferromagnetic coupling, and consequently no long-range magnetic order has b:::en observed under these conditi ons, as expected for isolated I D chains.
Crystal Growth & Design, 2012
Four new Co(II) containing coordination polymers have been synthesized using an ether bridged tricarboxylic acid ligand, o-cpiaH 3 (5-(2-carboxy-phenoxy)-isophthalic acid). This ligand readily reacts with CoCl 2 ·6H 2 O in the presence of different nitrogen donor ligands such as 1,10-phenanthroline (phen), 4,4′-bipyridyl (bpy), 4,4′azopyridine (apy), and 1,4-bis(4-pyridinylmethyl)piperazine (bpmp) under hydrothermal conditions to afford three 3D and one 2D coordination polymers,
Two new 1-D dicyanamide bridged polymeric complexes [Mn(μ1,5-dca)2(salicyh)2]n and {Ni(μ1,5-dca)(TTA)}n (dca=dicyanamide, ; salicyh=salicylic hydrazide; TTA=triethylenetetramine): Synthesis, structures and magnetic studies
Inorganica Chimica Acta, 2005
Yap, et al.. Two new 1-D dicyanamide bridged polymeric complexes [Mn(µ1,5-dca)2(salicyh)2]n and [Ni(µ1,5dca)(TTA)](ClO4)n (dca = dicyanamide, ; salicyh = salicylic hydrazide; TTA = triethylenetetramine): Synthesis, structures and magnetic studies. Inorganica Chimica Acta, Elsevier, 2005, vol. 358, n15, p.