1D coordination polymers of Cu(II) and Cu(II) dimers with a dicyanomethanide ligand

Several new 1D coordination polymers have been synthesised using the anionic ligand carbamoyldicyanomethanide, C(CN)₂(CONH₂)⁻ (cdm). The polymeric complexes [Cu(cdm)₂(py)₂]·2MeOH (1), [Cu(cdm)₂(4-Etpy)₂]·2MeOH (2), [Cu(cdm)₂(3,5-Me₂pzH)₂]·2MeOH (3) and [Cu(cdm)₂(3-HOCH₂py)₂]·2MeOH (4) (py = pyridine; 3,5-Me₂pzH = 3,5-dimethylpyrazole) contain Cu(II) atoms bridged by μ₂-(N,N′) cdm ligands between equatorial and axial coordination sites. The use of monodentate co-ligands brings about polymeric products, in contrast to the use previously of chelating co-ligands which facilitate the formation of discrete products. These 1D polymeric complexes are connected by hydrogen bonding between the amide functionalities and the lattice solvent. In the structures of 3 and 4 the neutral ligands also contain hydrogen bond donor groups that supplement the amide ring motif. Two other complexes have been obtained that are polymeric chains of alkoxide-bridged Cu(II) dimers. The complexes [Cu(cdm)(MeO)(2-amp)] (5) and [Cu(cdm)(dmap)] (6) (2-amp = 2-(aminomethyl)pyridine and dmap = dimethylaminopropoxide) are remarkably similar despite the different ligands that they contain. Bridging between dimers is via μ₂-(N,O) cdm ligands, consequently altering the nature of the hydrogen bonding between adjacent chains compared to the simple polymeric species 1–3.     

一个新型分子铁磁体: 氰根桥联的铜(II)-铁(III)配合物

合成和表征了一个新的分子磁体,氰根桥联的杂化型异金属配合物[Cu(en)]~3[Fe(CN)~6]~2.3H~O(en为乙二胺)。变温磁化率、零场冷却磁化强度(ZFCM)、场冷却磁化强度(FCM)和磁滞回线测量表明铜铁离子间存在着铁磁性相互作用,其铁磁相变温度为T~c=11.0K,矫顽力为20×10^-^4T,剩磁为1.70×10^-^1cm^3.mol^-^1.T。该化合物为杂化型铜(II)-铁(III)普鲁士蓝类中具有铁磁相变温度的首例。     

Hydroquinone-bridged dinuclear Cu(II) complexes and single-crystalline Cu(II) coordination polymers

Cationic dinuclear Cu(II) complexes 3 and 4 have been prepared using the novel hydroquinone-based imine chelators 2,5-((i)Pr(2)NCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (1) and 2,5-(pyCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (2), respectively (py = 2-pyridyl). X-Ray quality crystals of both complexes were grown from their DMF solutions. The sterically more encumbered compound crystallizes in the form of discrete dinuclear entities with Cu(II) centres in a distorted square-planar ligand environment (one coordination site is occupied by a DMF molecule). The pyridyl derivative 4 features dinuclear hydroquinone-bridged subunits similar to 3. However, the Cu(II) ions are now six-coordinate with two DMF molecules at an axial and an equatorial position of a Jahn-Teller-distorted octahedron. Moreover, the dinuclear subunits are no longer isolated but linked with each other via bridging hydroquinone oxygen atoms which occupy the second apical position of each octahedron. The structure suggests that the magnetic properties of the resulting coordination polymer of 4 could be described by a model valid for dimerized spin chains. As a result of this analysis the antiferromagnetic coupling constants J(1)/k(B) = 9.9 K (intradimer) and J(2)/k(B) = 0.9 K (interdimer) are obtained. Both in 3 and in 4, the hydroquinone --> semiquinone transition of the central bridging unit (E degrees ' = + 0.57 V, 3; E degrees ' = + 0.51 V, 4; DMF; vs. SCE) displays features of chemical reversibility. In the case of , reduction of Cu(II) centres requires a peak potential of E(p) = - 0.42 V.     

Malonato-bridged hexamethylenetetramine coordination polymers containing Mn(II) and Cu(II)

Two malonato-bridged hexamethylenetetramine coordination polymers, M₂(hmt)(H₂O)₂(mal)₂ [hmt?=?hexamethylenetetramine, mal?=?malonate(2-), M?=?Mn (1), Cu (2)] were prepared and structurally characterized. The isostructural complexes are orthorhombic, space group Imm2, with a?=?7.104(1), b?=?15.982(3), c?=?7.702(1)?Å, Z?=?2, D _calc?=?1.862?g?cm^?3(1) and a?=?6.962(3), b?=?15.500(7), c?=?7.627(3)?Å, Z?=?2, D _calc?=?2.047?g?cm^?3for 2. The transition metals are octahedrally coordinated by one nitrogen atom of an hmt ligand and five oxygen atoms of a water molecule and three malonate anions. The latter coordinate in chelating/bis-monodentate mode to give 2D layers with a (4,?4) topology, and which are pillared by bridging bidentate hmt ligands to generate an open 3D framework with channels extending in the [001] direction. Over the temperature range 5–300?K, 2 behaves paramagnetically, following the Curie–Weiss law χ_m(T???θ)?=?4.521(6)?cm³mol^?1K with a Weiss constant θ?=??4.8(2)?K.     

Direct evidence of nanowires formation from a Cu(I) coordination polymer

In this work we present both spectroscopic and morphological evidence showing one-dimensional organization of [CuBr(HIN)]n (HIN=isonicotinic acid) on surfaces.     

Cu(II)/Cd(II) coordination polymers based on polycarboxylate and 2-(2-pyridyl)benzimidazole

Three polycarboxylate coordination polymers containing 2-(2-pyridyl)benzimidazole as co-ligand, [Cu(Bdc)(2-PyBIm)] _n (1), [Cu(HBtc)(2-PyBIm)] _n (2) and [Cd₂(HBtc)₂(2-PyBIm)₂] _n ·; nH₂O (3) (H₂Bdc?=?1,4-benzenedicarboxylic acid; H₃Btc?=?1,3,5-benzenetricarboxylic acid), have been synthesized and characterized by elemental analyses, IR spectra, TG-DSC and X-ray structural analyses. Complex 1 is a one-dimensional zigzag chain in which the Cu(II) is cis six-coordinated by two chelating carboxyl groups and a 2-PyBIm ligand. Complex 2 is a two-dimensional (4, 4) network in which H₃Btc is partially deprotonated. Complex 3 has a three-dimensional framework in which one Cd(II) is six-coordinate and the other is seven-coordinate. All 2-PyBIm groups are neutral, chelating, bidentate ligands in 1–3. These complexes are quite thermally stable. The luminescence of 3 has also been investigated.     

Synthesis and structural characterization of 2-D layered copper(II) styrylphosphonate coordination polymers

We report the synthesis, physicochemical characterization, and crystal structure of Cu-SP (SP?=?styrylphosphonic acid, H₂O₃PCH=CH₂(C₆H₅)), the first reported example of a metal derivative of SP. The starting SP acid was fully characterized by X-ray single-crystal diffractometry, elemental analysis (C and H), ³¹P-NMR, ¹³C-NMR, ¹H-NMR, HPLC, UV–vis, MS, TG, and FT-IR spectroscopy. The copper(II) derivative was synthesized and characterized by DTA-TG and FT-IR, and also its structure was determined from powder data. The crystal structure was refined by the Rietveld method. The crystal structure of Cu-SP shows a layered 2-D architecture, where the organic moieties are pointed toward the interlamellar space. The inorganic layers are composed of Cu²⁺ dimers, where the coordination geometry of Cu²⁺ can be described as distorted trigonal bipyramid. The three coplanar oxygens (O2, O3, and O3) have bond distances of 2.165(9), 1.982(9), and 2.103(11)?Å, respectively. The bond lengths for the apical oxygens (O1 and O2) are 1.908(13) and 1.996(11)?Å, respectively.     

Sorption-desorption behavior of bispyrazolato-copper(II) 1D coordination polymers

A new polycrystalline vapochromic polymorph of the one-dimensional copper bispyrazolate polymer reversibly and selectively absorbs a number of small molecules; the crystal structures of the anhydrous and fully hydrated species, determined by powder diffraction methods, are markedly different despite their simple, fast, and reversible interconversion.     

Controlled aggregation of heterometallic nanoscale Cu12Ln6 clusters (Ln = Gd(III) or Nd(III)) into 2D coordination polymers

Discrete dinuclear and polymeric heterometallic copper(II)-lanthanide(III) complexes have been synthesized upon variation of pH and characterized by X-ray diffraction analysis. Reactions of the ligand Htza (tetrazole-1-acetic acid) with copper(II) and lanthanide(III) salts gave dinuclear [CuLn(tza)4(H2O)5Cl] complexes at the low pH of 3.5 and 2D heterometallic coordination polymers with high-nuclearity [{Cu2(OH)2}2{Cu12Ln6(mu3-OH)24(Cl)(1/2)(NO3)(1/2)(tza)12(H2O)18}](NO3)(9).8H2O (Ln = Gd or Nd) at a higher pH of 6.6. The acidity of the reaction solution can cause drastic changes in the structures of the products. In the dinuclear complexes, each pair of adjacent dinuclear molecules is linked through hydrogen bonds and pi-pi stacking interactions, and the whole structure is a hydrogen-bonded three-dimensional cubic net. In the coordination polymers, the connecting nodes are [Cu12Ln6] units, which are interconnected by [Cu2O2] units into two-dimensional structures. Magnetic studies exhibit the existence of weak exchange interactions between the Cu(II) and Ln(III) ions bridged by carboxylate and hydroxy ligands.     

Design and characterization of Cu(II) complexes from 2-benzoylpyridine benzhydrazone: Crystallographic evidence for coordination versatility

The syntheses and characterization of six copper(II) complexes of 2-benzoylpyridine benzhydrazone in the form of [Cu(BPB)₂], [Cu(BPB)Cl]·H₂O, [Cu(BPB)Br], [Cu₂(BPB)₂](ClO₄)₂·4H₂O, [Cu(BPB)N₃]·H₂O, and [Cu(BPB)NCS]·H₂O·CH₃OH are reported. The analytical methods used for the characterization of complexes include partial elemental analyses, IR, electronic and EPR spectra, conductivity measurements, magnetic susceptibility measurements and single crystal X-ray diffraction. From the crystal structure, it is clear that the hydrazone adopts the E conformation about the azo bond to attach to the metal through the N_py–N_azo–O chelating system. In the EPR spectra of complexes in DMF at 77 K four hyperfine quartets in the parallel region could be resolved and a half field signal is observed at 1500 G for complex [Cu₂(BPB)₂](ClO₄)₂·4H₂O in polycrystalline state at 298 K which gives evidence for its binuclear nature indicating a weak interaction between the two Cu(II) ions.     

Thermal decomposition of crystalline Ni(II)-Cr(III) layered double hydroxide: a structural study of the segregation process

A structural study of the thermal evolution of Ni(0.69)Cr(0.31)(OH)(2)(CO(3))(0.155) x nH(2)O into NiO and tetragonal NiCr(2)O(4) is reported. The characteristic structural parameters of the two coexisting crystalline phases, as well as their relative abundance, were determined by Rietveld refinement of powder x-ray diffraction (PXRD) patterns. The results of the simulations allowed us to elucidate the mechanism of the demixing process of the oxides. It is demonstrated that nucleation of a metastable nickel chromite within the common oxygen framework of the parent Cr(III)-doped bunsenite is the initial step of the cationic redistribution. The role that trivalent cations play in the segregation of crystalline spinels is also discussed.     

Synthesis and structural characterization of two dimensional cadmium(II) coordination polymers

Reactions of Cd(NO₃)₂?·?4H₂O with NH₄SCN, ppz (ppz?=?piperazine) and bpa (bpa?=?bis(4-pyridyl)ethane) in CH₃OH afforded the cavity-containing rectangular grids {Cd(SCN)₂(ppz)} _n (1) and {Cd(NCS)₂(bpa)} _n (2). The ppz ligand in 1 is coordinated to the metal through both nitrogen atoms to form the 1-D zig-zag chain structure and distorted {CdN₄S₂} octahedral coordination geometry at each Cd center is completed by pairs of bidentate thiocyanato ligands. Complex 2 has the 2-D arrangement constructed through 1-D double μ(N,S) end-to-end bridging thiocyanato groups bridging Cd(II) chains interconnected through disordered bpa ligands.     

Magnetic studied of a binuclear Cu(II) complex constructed from Cu(II) macrocyclic complex

A new binuclear copper(II) compound [(CuL)₂(Tpha)](ClO₄)₂ · 4H₂O (I), where L = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1^6,9]octadecane, Tpha = terephthalate dianion, has been constructed and structurally characterized by X-ray crystallography. Crystal analysis denotes that complex I crystallizes in the monoclinic system, space group P2₁/c with a = 11.115(2), b = 13.185(3), c = 16.184(3) Å and β = 105.68(3)°. Magnetic measurements confirm that I present an antiferromagnetic interaction between the paramagnetic ions.     

Self-assembled 3D heterometallic Cu(II)/Fe(II) coordination polymers with octahedral net skeletons: structural features, molecular magnetism, thermal and oxidation catalytic properties

The new three-dimensional (3D) heterometallic Cu(II)/Fe(II) coordination polymers [Cu(6)(H(2)tea)(6)Fe(CN)(6)](n)(NO(3))(2n)·6nH(2)O (1) and [Cu(6)(Hmdea)(6)Fe(CN)(6)](n)(NO(3))(2n)·7nH(2)O (2) have been easily generated by aqueous-medium self-assembly reactions of copper(II) nitrate with triethanolamine or N-methyldiethanolamine (H(3)tea or H(2)mdea, respectively), in the presence of potassium ferricyanide and sodium hydroxide. They have been isolated as air-stable crystalline solids and fully characterized including by single-crystal X-ray diffraction analyses. The latter reveal the formation of 3D metal-organic frameworks that are constructed from the [Cu(2)(μ-H(2)tea)(2)](2+) or [Cu(2)(μ-Hmdea)(2)](2+) nodes and the octahedral [Fe(CN)(6)](4-) linkers, featuring regular (1) or distorted (2) octahedral net skeletons. Upon dehydration, both compounds show reversible escape and binding processes toward water or methanol molecules. Magnetic susceptibility measurements of 1 and 2 reveal strong antiferromagnetic [J = -199(1) cm(-1)] or strong ferromagnetic [J = +153(1) cm(-1)] couplings between the copper(II) ions through the μ-O-alkoxo atoms in 1 or 2, respectively. The differences in magnetic behavior are explained in terms of the dependence of the magnetic coupling constant on the Cu-O-Cu bridging angle. Compounds 1 and 2 also act as efficient catalyst precursors for the mild oxidation of cyclohexane by aqueous hydrogen peroxide to cyclohexanol and cyclohexanone (homogeneous catalytic system), leading to maximum total yields (based on cyclohexane) and turnover numbers (TONs) up to about 22% and 470, respectively.     

Lanthanide(III)-cobalt(II) heterometallic coordination polymers with radical adsorption properties

Two new coordination polymers {[Ln(2)(PDA)(6)Co(3)(H(2)O)(6)] x xH(2)O}(n) [Ln = Nd, x = 7 (1); Ln = Gd, x = 3.25 (2); H(2)PDA = pyridine-2,6-dicarboxylic acid] have been prepared under hydrothermal conditions with Ln(NO(3))(3) x 6H(2)O, CoO, and H(2)PDA in a molar ratio of 2:3:6. X-ray crystallographic analyses reveal that they crystallize in the hexagonal group P6/mcc and exhibit a nanotubular 3D framework. The adsorption experiment shows that 1 and 2 can adsorb radicals, which is proven by electron paramagnetic resonance spectra with the characteristic bands of the radicals at g = 2.006 and 2.005, respectively.     

Synthesis,structure and characterization of new 1D and 2D Ni(II) coordination polymers

Two new Ni(II) coordination polymers, namely [Ni₃(Hsdac)₂(sdac)₂(2,2′-bipy)₂] (1) and [Ni₂(sdac)₂(4,4′-bipy)₂]·2H₂O (2) (sdba = 4,4′-sulfonyldibenzoate, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses. Compound 1 possesses an interesting chain structure. Adjacent chains are further linked through H-bond interactions between Hsdac ligands to give a two-dimensional (2D) supramolecular architecture. Compound 2 displays an unusual 2D polyrotaxane-like network.     

Inhibition of two Cu(II) and Mn(II) coordination polymers on the surgical site infections by inhibiting the bacterial biofilm formation

Within this work, two novel Cu(II) and Mn(II)-based coordination polymers (CPs) along with chemical compositions of {[Cu₂(L¹)(1,4-NDC)₂]·3H₂O}_n (1, 1,4-H₂NDC = Naphthalene-1,4-dicarboxylic acid, L¹ ​= ​di(1H-imidazole-1-yl)methane) and [Mn₃(L²)₂(H₂O)₂(1,4-NDC)₂]_n (2, L² ​= ​1,4-di(1H-imidazole-1-yl)benzene) have been completed in success via related metal salts reaction with 1,4-H₂NDC ligand in existence of various N-donor co-ligands. We discovered its application values on the surgical site infections (SSI) along with corresponding mechanism in the interim. We evaluated inflammatory cytokines released into the urine through ELISA detection kit after compound treatment. Then, we discovered the inhibitory effect of compound on the bacterial biofilm formation via real time RT-PCR.     

2D coordination polymers of macrocyclic oxamide with polycarboxylates: syntheses, crystal structures and magnetic properties

Five new 2D coordination polymers, [Co(nip)(CuL)(H(2)O)]·CH(3)OH (1), [Mn(ip)(NiL)]·0.63H(2)O (2), [Cu(ip)(CuL)] (3), [Mn(6)(CuL)(6)(btc)(4)(H(2)O)(4)]·7H(2)O (4), and [Cu(CuL)(Hbtc)(H(2)O)] (5)(ML, H(2)L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-diene; H(2)nip = 5-nitroisophthalic acid; H(2)ip = m-isophthalic acid; H(3)btc = 1,3,5-benzenetricarboxylic acid) have been synthesized by a solvothermal method and characterized by single-crystal X-ray diffraction. Complexes 1-5 exhibit different 2D layered structures formed by Co(2)Cu(2) (1), Mn(2)Ni(2) (2), Cu(4) (3), Mn(3)Ni(3) (4), Cu(4) (5) units, respectively, via the oxamide and diverse carboxylic acid bridges. Compounds 1, 2, 3 and 5 are uninodal 4-connected (4, 4)-grids topology, while complex 4 possesses a 2D network with (3, 4)-connected (4(2).8)(4)(4(3).6(2).8)(3) topology. The results of magnetic determination show pronounced antiferromagnetic interactions in 1-4.