Search results for "Coordination polymer"
showing 10 items of 201 documents
Highly efficient temperature-dependent chiral separation with a nucleotide-based coordination polymer.
2018
We report a new chiral coordination polymer, prepared from the cytidine 5′-monophosphate (CMP) nucleotide, capable of separating efficiently (enantiomeric excess of ca. 100%) racemic mixtures of L- and D-Asp in a temperature-dependent manner. The crystal structure of the host–guest adsorbate, with the D-Asp guest molecules loaded within its channels, could be solved allowing a direct visualization of the chiral recognition process.
Versatility and dynamics of the copper(I) coordination sphere in sterically hindering tris(pyrazolyl)methane-incorporating macrobicycles
2009
Two arene-capped macrobicycles (1 and 2) incorporating the tris(pyrazolyl)methane (Tpm) chelate have been prepared from a benzylthiol-functionalized Tpm precursor (3). Reaction of either macrobicycle with Cu(CH3CN)4+ leads to tetrahedral or trigonal-planar, fluxional complexes incorporating the Cu(CH3CN)+ subunit ([Cu(1)(CH3CN)]+ and [Cu(2)(CH3CN)]+). The acetonitrile ancillary ligand does not fit inside the macrobicycle cavity and can be removed by heating under vacuum, which produces the [Cu(1)]+ and [Cu(2)]+ species probably involving intramolecular thioether coordination. The [Cu(1)(CH3CN)]+ complex was shown to convert slowly in wet acetone into a helical coordination polymer, which is…
Crystal structure of the coordination polymer [FeIII2{PtII(CN)4}3]
2015
[EN] The title complex, poly[dodeca--cyanido-diiron(III)triplatinum(II)], [FeIII2{PtII(CN)4}3], has a three-dimensional polymeric structure. It is built-up from square-planar [PtII(CN)4] 2 anions (point group symmetry 2/m) bridging cationic [FeIIIPtII(CN)4] + 1 layers extending in the bc plane. The FeII atoms of the layers are located on inversion centres and exhibit an octahedral coordination sphere defined by six N atoms of cyanide ligands, while the PtII atoms are located on twofold rotation axes and are surrounded by four C atoms of the cyanide ligands in a square-planar coordination. The geometrical preferences of the two cations for octahedral and square-planar coordination, respectiv…
Molecular, Supramolecular Structures Combined with Hirshfeld and DFT Studies of Centrosymmetric M(II)-azido {M=Ni(II), Fe(II) or Zn(II)} Complexes of…
2021
The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]
Heterobimetallic MOFs containing tetrathiocyanometallate building blocks: Pressure-induced spin crossover in the porous {Fe II(pz)[Pd II(SCN) 4]} 3D …
2012
Here we describe the synthesis, structure, and magnetic properties of two related coordination polymers made up of self-assembling Fe(II) ions, pyrazine (pz), and the tetrathiocyanopalladate anion. Compound {Fe(MeOH) 2[Pd(SCN) 4]}·pz (1a) is a two-dimensional coordination polymer where the Fe(II) ions are equatorially coordinated by the nitrogen atoms of four [Pd(SCN) 4] 2- anions, each of which connects four Fe(II) ions, forming corrugated layers {Fe[Pd(SCN) 4]} ∞. The coordination sphere of Fe(II) is completed by the oxygen atoms of two CH 3OH molecules. The layers stack one on top of each other in such a way that the included pz molecule establishes strong hydrogen bonds with the coordin…
Nanowire iron(III) coordination polymer based on 1,2,4-triazolo[1,5-a]pyrimidine and chloride ligands
2019
Abstract The neutral ligand 1,2,4-triazolo[1,5-a]pyrimidine (tp) has been employed to prepare a new coordination compound of Fe(III), [FeCl3(tp)2]n (1). Compound 1 was investigated by single crystal X-ray diffraction and found to be a coordination polymer forming a ladder structure based on metal–ligand interactions, while H-bonding and aromatic interactions contribute to the supramolecular self-assembly into a 3D nanostructured material. The polymeric assembly is retained also in solution, where a metallo-supramolecular polymer based on coordinative metal–ligand binding is present, as shown by dynamic light scattering (DLS) measurements. The redox properties of the Fe(III) coordination pol…
Homoleptic iron(II) complexes with the ionogenic ligand 6,6′-Bis(1H-tetrazol-5-yl)-2,2′-bipyridine: spin crossover behavior in a singular 2D spin cro…
2015
Deprotonation of the ionogenic tetradentate ligand 6,6′-bis(1H-tetrazol-5-yl)-2,2′-bipyridine [H2bipy(ttr)2] in the presence of FeII in solution has afforded an anionic mononuclear complex and a neutral two-dimensional coordination polymer formulated as, respectively, NEt3H{Fe[bipy(ttr)2][Hbipy(ttr)2]}·3MeOH (1) and {Fe[bipy(ttr)2]}n (2). The anions [Hbipy(ttr)2]− and [bipy(ttr)2]2– embrace the FeII centers defining discrete molecular units 1 with the FeII ion lying in a distorted bisdisphenoid dodecahedron, a rare example of octacoordination in the coordination environment of this cation. The magnetic behavior of 1 shows that the FeII is high-spin, and its Mössbauer spectrum is characteriz…
Polymetallic oxalate-based 2D magnets: Soluble molecular precursors for the nanostructuration of magnetic oxides
2010
Here we describe the synthesis and magnetic characterization of a family of 2D polymetallic oxalate-bridged polymeric networks with general formula [M(II)(H(2)O)(2)](3)[M(III)(ox)(3)](2)(18-crown-6)(2) (M(III) = Cr, Fe; M(II) = Mn, Fe, Co, Ni; 18-crown-6 = C(12)H(24)O(6)). Depending on the nature of the trivalent metal ion, they exhibit ferro- (Cr(3+)) or ferrimagnetic (Fe(3+)) ordering in the 3.6-20 K interval. In contrast with most of the oxalate-bridged CPs reported so far, these complexes do not need any additional templating cation for their assembly and represent the first series of oxalate-based polymeric networks which can be considered intrinsically neutral. As previously observed …
[Ni(cyclam)(μ1,3-dca)2Cu(μ1,5-dca)2]: A Genuine 3D Bimetallic Coordination Polymer Containing Both μ1,3- and μ1,5-Bidentate Dicyanamide Bridges and …
2005
The structure of [Ni(cyclam)(μ 1 , 3 -dca) 2 Cu(μ 1 , 5 -dca) 2 ], a genuine 3D dicyanamide-bridged bimetallic coordination polymer, is made up of 2D [Cu(μ- 1 , 5 dca) 2 ] n layers connected by [Ni(cyclam)(μ 1 , 3 -dca) 2 ] bridging moieties; it exhibits a ferromagnetic exchange interaction between copper(ll) and nickel(ll) ions through the μ 1 , 3 -bidentate dicyanamide bridges.
Copper(II)-methylmalonate complexes with unidentate N-donor ligands: Syntheses, structural characterization and magnetic properties
2009
Abstract Two new methylmalonate-bridged copper(II) complexes with the formulas [Cu(3-Ipy)(Memal)(H 2 O)] ( 1 ) and [Cu(2,4′-bpy)(Memal)(H 2 O)] · 3H 2 O ( 2 ) [Memal = methylmalonate dianion, 3-Ipy = 3-iodopyridine, 2,4′-bpy = 2,4′-bipyridine] have been synthesized and characterized by X-ray diffraction. Both compounds crystallize in the monoclinic space group P 2 1 / n and Z = 4, with unit cell parameters a = 8.5874(13) A, b = 7.1738(14) A, c = 19.093(5) A, β = 99.509(15)° in 1 and a = 17.375(4) A, b = 7.3305(14) A, c = 14.247(3) A, β = 111.409(15)° in 2 . The structures of 1 and 2 consist of zigzag chains of anti-syn carboxylate-bridged copper(II) ions running along the b directi…