Search

The combination of electron-deficient viologen ligands with electron-rich POMs is a typical acceptor–donor system that has recently received much attention. Under solvothermal and hydrothermal conditions, by introducing three symmetric viologen ligands into POM-based hybrid materials, we successfully constructed four POMs–viologen inorganic–organic hybrid compounds, namely (1,3-bcbpy)2·(δ-Mo8O26) (1) (1,3-bcbpy·2Cl = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridine dichloride), {CoII(1,4-bcbpy)2(H2O)2[H2(β-Mo8O26)]}·2H2O·2CH2O (2), (1,4-bcbpy)2·(δ-Mo8O26)·2H2O (3) (1,4-bcbpy·2Cl = 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridine dichloride, CH2O = formaldehyde), and {CuII(1,1-pmbby)2(H2O)[H2(β-Mo8O26)2]}·5H2O·C2H7N (4) (1,1-pmbby·2Cl = 1,1′-[1,4-phenylbis(methylene)]bis-(4,4′-bipyridine)dichloride, C2H7N = dimethylamine). These four compounds exhibit different fascinating structures, especially compound 4 is a typical metal–organic framework. Compounds 1–4 exhibit good discoloration behaviors under various external stimuli. For example, compounds 1–4 showed a positive response to the irradiation from a 300 W Xe lamp. When a positive voltage was applied to the ECD based on compounds 1–4, 1/2/3/4-ECD underwent a significant color conversion. What's more, compound 4 also showed obvious discoloration results after heating. In a word, 1–4 are multifunctional discoloration materials under different external stimuli. In addition, the coated filter paper prepared based on compound 3 can be used as a new printing material medium and can be successfully applied in erasable inkless printing and dual anti-counterfeiting. [ABSTRACT FROM AUTHOR]

Two new cyano-bridged coordination polymers, {[Ni(bpe)(H2O)2][Ni(CN)4]·2H2O}n (1) and {[Cu(bpe)(H2O)2][Ni(CN)4]·ethanol}n (2) (bpe = 1,2-bis(4-pyridyl)ethane) were synthesized and characterized. This was part of a study attempting to rationalize the formation of Hofmann coordination polymers over their aqua-derivatives, in which we found that the length of the ligand does not control the outcome of the synthesis. In the initial phase of thermogravimetric analysis, compound 1 lost the guest water molecule while compound 2 lost its guest ethanol. Single crystal X-ray diffraction revealed that both compounds crystallize in P1¯ with similar unit cell parameters. In both compounds, the Ni(II) ion is coordinated with four cyanide–carbon atoms in a square planar geometry and Cu(II) or the second Ni(II) ion adopts a distorted octahedral coordination by two bpe ligands, two bridging cyano groups, and two water molecules. In both structures, chains composed of adjacent [Ni(C12H12N2)(H2O)2]2+ (for 1) or [Cu(C12H12N2)(H2O)2]2+ (for 2) are further linked together via [Ni(CN)4]2− units and extend to generate a two-dimensional framework. The presence of disordered terminal cyanide moieties in 1 could be attributed to a larger volume available to this moiety in the structure of 1. The BET surface areas of the activated phases 1′ of 1 and 2′ of 2 are 28 m2 g−1 and 5 m2 g−1, respectively, and originally, they have no pores to accommodate gas molecules at low pressure (1 atm). 1′ does not adsorb carbon dioxide at 195 K (0.30 mmol g−1), 273 K (0.086 mmol g−1) and 298 K (0.056 mmol g−1), or hydrogen at 77 K, but it shows an affinity to adsorb nitrogen (around 2.5 mmol g−1) at 77 K and water vapor molecules (around 0.95 mmol g−1) at 298 K with typical type-II isotherms. 2′ adsorbs a small quantity of water vapor (around 0.20 mmol g−1) at 298 K and does not adsorb carbon dioxide at 195 K (0.125 mmol g−1), 273 K (0.069 mmol g−1) and 298 K (0.062 mmol g−1), or hydrogen at 77 K, but shows more affinity to adsorb nitrogen (around 1.2 mmol g−1) at 77 K. [ABSTRACT FROM AUTHOR]

A thiophene-derived Schiff base ligand (E)-2-morpholino-N-(thiophen-2-ylmethylene)ethanamine was used for the synthesis of M(II) complexes, [TEM(M)X2] (M = Co, Cu, Zn; X = Cl; M = Cd, X = Br). Structural characterization of the synthesized complexes revealed distorted tetrahedral geometry around the M(II) center. In vitro investigation of the synthesized ligand and its M(II) complexes showed considerable anti-urease and leishmanicidal potential. The synthesized complexes also exhibited a significant inhibitory effect on urease, with IC50 values in the range of 3.50–8.05 μM. In addition, the docking results were consistent with the experimental results. A preliminary study of human colorectal cancer (HCT), hepatic cancer (HepG2), and breast cancer (MCF-7) cell lines showed marked anticancer activities of these complexes. [ABSTRACT FROM AUTHOR]

Four Ni, Co, Cu, Zn-containing coordination polymers incorporating 4,4′,4′′,4′′′-tetrakiscarboxyphenylsilane (H4tcps) and 1,3,5-tris(2-methyl-1H-imidazol-1-yl)benzene (tmib) ligands, namely [Ni6(tcps)3(tmib)4(H2O)2] (1), [Co6(tcps)3(tmib)4] (2), [Cu2(tcps)(tmib)(H2O)] (3) and [Zn2(tcps)(tmib)] (4), were synthesized by the solvothermal method. Compounds 1 and 2 were isostructural with three-dimensional (3D) (3,4)-connected frameworks. Compounds 3 and 4 possessed (3,4)-connected 3D networks with (6·82)(6·85)(62·82·102)(62·8) and (4·6·8)(4·63·82)(66)(67·83) topology, respectively. The thermal derivatives of compounds 1 and 2, Co-800 and Ni-700, exhibited low OER overpotentials of 338 and 388 mV to achieve a current density of 10 mA cm−2 and hold their electrocatalytic activity for at least 9 hours in 1 M KOH. [ABSTRACT FROM AUTHOR]

Two new copper(II) complexes have been obtained by the reaction of sterically crowded triphenodioxazine ligands with Cu(II) hexafluoroacetylacetonate. Compound 1 is a co-crystal of Cu(hfac)2 moieties and triphenodioxazine molecules within a quasi-one-dimensional crystal structure with only weak Cu⋯N short intermolecular interactions (Cu⋯N distances are equal to 2.69(1) and 2.75(1) Å). In contrast, complex 2 has a binuclear structure with two Cu(hfac)2 units bridged through triphenodioxazine ligand with the covalent Cu–N bond length of 2.335(2) Å. The magnetic AC susceptibility data show that in spite of the absence of zero-field splitting in the Cu(II) ion having the ground state with spin S = 1/2, both compounds demonstrate slow magnetic relaxation at the applied magnetic field. For a quasi-one-dimensional complex 1, the optimal field for observing slow magnetic relaxation is 400 Oe, while for the binuclear complex it is 2500 Oe. The observed temperature dependence of the relaxation time in 1 is well described by the combination of Raman and direct mechanisms of relaxation, while for complex 2 the inclusion of Raman mechanism and quantum tunneling of magnetization is required to describe the relaxation behavior. [ABSTRACT FROM AUTHOR]

This work aims to synthesize multifunctional materials with tunable emission properties. To pursue this, three isomeric ligands; 2-(1H-1,2,4-triazol-1-yl)pyridine (L1), 3-(1H-1,2,4-triazol-1-yl)pyridine (L2) and 4-(1H-1,2,4-triazol-1-yl)pyridine (L3) were reacted with CuI to afford three different coordination polymers, [Cu2(μ3-I)2(L1)2]nCP1, [Cu2(μ2-I)2(L2)2]nCP2 and [Cu(μ2-I)(L3)]nCP3, respectively. CP1 consists of a 1D chain comprising double-stranded Cu2I2 secondary building units (SBUs), where each copper is coordinated with the triazolyl nitrogen of the ligand on each side of the chain while the pyridine nitrogen remains pendant. Contrary to this, both pyridine and triazolyl nitrogens of L2 and L3 coordinate to Cu to give 1D and 2D CP2 and CP3, respectively. CP2 has a discrete Cu2I2 rhomboid SBU bridged by two L2 ligands, whereas CP3 has Cu–I single chains bridged by two L3 ligands to give a 2D sheet structure. All three coordination polymers are emissive at room temperature with the emission colour varying from green and yellow to orange with a λmax of 538, 575 and 600 nm, respectively for CP1 to CP3. CP1 and CP3 show luminescence thermochromism on lowering the temperature from 298 K to 77 K, changing hues from green to blue and orange to yellow, respectively. In addition to unique emission properties, these CPs exhibit semiconductor behaviour, with electrical conductivity in the range of 10−7 S cm−1. It is proposed that the presence of the Cu2I2 double-stranded chain provides a better and continuous overlap of copper and iodine orbitals, giving better conductivity to CP1 compared to CP2 and CP3. [ABSTRACT FROM AUTHOR]

Cu(I)-based coordination polymers (CPs) are known as efficient emissive materials providing an eco-friendly and cost-effective platform for the development of various functional materials and sensors. In addition to the nature of the metal center, organic ligands also play a crucial role in controlling the emissive properties of coordination polymers. Herein, we report on the synthesis of dithiane- and dithiolane-substituted triphenylamine ligands L1 and L2. These ligands were found to be emissive both in the solid state and in solution. In addition, these ligands exhibit solvatochromic behaviour due to the twisted intramolecular charge transfer (TICT) phenomenon. Next, coordination behaviour of these ligands was explored with Cu(I)X salts (X = Br and Cl) and four new 1D coordination polymers [{Cu(μ2-X)2Cu}(μ2-L)]n, CP1 (X = Br, L = L1), CP2 (X = Cl, L = L1), CP3 (X = Br, L = L2), and CP4 (X = Cl, L = L2) were synthesized and crystallographically characterized. The emission behaviour of all the CPs suggests ligand-centered transitions. On mechanical grinding, emission maxima (λem) for CP1 and CP2 were blue-shifted, whereas for CP3 and CP4 red-shifts were observed. All CPs were found to emit at 448 nm with increased intensity after grinding. It is supposed that grinding is responsible for a change in the spatial arrangement (dihedral angles) of the phenyl groups of triphenylamine, causing the observed emission shifts. Furthermore, the higher emission intensity after grinding suggests the occurrence of a similar phenomenon as an aggregation-induced quenching in these CPs. [ABSTRACT FROM AUTHOR]

Starting from imidazolium chlorides bearing bulky nitrogen donors, a series of four complexes, mainly [Cu (C^N)Cl]n coordination polymers were obtained directly as luminescent species by simple filtration from the aqueous reaction medium, highlighting a simple, eco-friendly, robust and reproducible synthetic procedure. Additionally, we have shown on the most efficient example that chloride could be exchanged very easily by other halides/pseudohalides (Br-, I-, NCS-, N3 -) allowing to slightly modulate the emitted colour while conserving the polymeric structure, except for azide for which a dimer was obtained. The combination of chemical analyses, of photoluminescence studies in the solid state including quantum yield measurement and X-ray diffraction on single crystals and as-synthesized microcrystalline powders highlighted that the polymeric luminescent species was indeed obtained directly by simple filtration and that no major alteration of the structure was observed upon recrystallisation. Samples of all polymeric complexes displayed remarkable stability towards air oxidation remaining unchanged upon storage for several months and partially retaining their photoluminescence properties even after a thermal treatment at 100 °C for 24 h. [ABSTRACT FROM AUTHOR]

The two triple-armed species tris(2-carboxyethyl)nitromethane (H3tcenm) and tris(2-carboxyethyl)phosphine (H3tcep) have been used to synthesize seven uranyl ion complexes under (solvo)-hydrothermal conditions and in the presence of various structure-directing cations. The three carboxylate groups chelate three different cations and the nitro group is uncoordinated in [H2NMe2][UO2(tcenm)]·3H2O (1), [C(NH2)3][UO2(tcenm)]·0.5H2O (2) and [PPh3Me][UO2(tcenm)] (3), which crystallize as diperiodic coordination polymers with the hcb topology and minor variations in shape depending on the counterion. The two isomorphous complexes [UO2(tcenm)M(bipy)2][UO2(tcenm)]·3H2O, with M = Ni (4) or Cu (5) and bipy = 2,2′-bipyridine, display the same arrangement, with a M(bipy)22+ group bridging two adjoining carboxylate donors in one uranyl equatorial plane. [(UO2)2(tcenm)2Cu(R,S-Me6cyclam)]·2H2O (6), where R,S-Me6cyclam = 7(R),14(S)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, is the only triperiodic framework in the series, with the tcs topology resulting from CuII pillaring diperiodic, uranyl-based sql networks. H3tcep is oxidized in situ to give the phosphine oxide H3tcepo, which is partially deprotonated in [UO2(Htcepo)] (7); the phosphine oxide and the two carboxylate groups are coordinated, and the diperiodic, three-dimensional network formed has the point symbol {66} and the vertex symbol 62·62·63·66·64·64, with the rings involved in Hopf links formation. Only complexes 3 and 7 are significantly emissive in the solid state, with photoluminescence quantum yields of 9%, and the emission maxima positions are in agreement with the number of uranyl equatorial donors. [ABSTRACT FROM AUTHOR]

The tetratopic 1,4-bis(2-phenylethoxy)-2,5-bis(3,2′:6′,3′′-terpyridin-4′-yl)benzene (1) and 1,4-bis(3-phenylpropoxy)-2,5-bis(3,2′:6′,3′′-terpyridin-4′-yl)benzene (2) ligands have been prepared and fully characterised. Combination of ligand 1 or 2 and [M(hfacac)2]·xH2O (M = Cu, x = 1; M = Zn, x = 2) under conditions of crystal growth by layering led to the formation of [Cu2(hfacac)4(1)]n·3.6n(1,2-Cl2C6H4)·2nCHCl3, [Zn2(hfacac)4(1)]n·nMeC6H5·1.8nCHCl3, [Cu2(hfacac)4(2)]n·nMeC6H5·2nH2O, [Cu2(hfacac)4(2)]n·2.8nC6H5Cl and [Cu2(hfacac)4(2)]n·2n(1,2-Cl2C6H4)·0.4nCHCl3·0.5nH2O. For each compound, single-crystal X-ray analysis revealed the assembly of a planar (4,4)-net in which the tetratopic ligands 1 or 2 define the nodes. The metal centres link two different bis(3,2′:6′,3′′-tpy) ligands via the outer pyridine rings; whereas copper(II) has N-donors in a trans-arrangement, zinc(II) has them in cis. This difference between the copper(II) and zinc(II) coordination polymers modifies the architecture of the assembly without changing the underlying (4,4)-network. [ABSTRACT FROM AUTHOR]

Three coordination complexes {[Cu(pydco)(pz)0.5(H2O)]·H2O}n (1), [Cu(pydco)(phen)(H2O)]·2H2O (2), and [Zn2(pydco)(phen)2Cl2]·2H2O (3) have been synthesized at room temperature using a mixed-ligand system including pyridine-2,6-dicarboxylic acid N-oxide (H2pydco) as O-donor as well as pyrazine (pz) and 1,10-phenanthroline (phen) as N,N′-bidentate donors. Single-crystal X-ray diffraction (XRD) revealed that 1 forms a 1D-coordination polymer through bridging pz units while 2 and 3 form discrete complexes in which endo-bidentate phen can only connect with one metal centre via a five-membered chelate ring. Also, pydco2− can form a six-membered chelate ring around the metal ion via the N-oxide oxygen and one carboxylate oxygen. However, another carboxylate group of this ligand can also participate in the coordination and create unique structures in 1 and 3. Subsequently, 1–3 can expand their structures into 2D-supramolecular networks through π⋯π stacking or H-bonding interactions. Recurrent π⋯π stacking motifs in all compounds have been further analyzed energetically using DFT calculations and characterized using the quantum theory of "atoms-in-molecules" (QTAIM) and noncovalent interaction plot (NCIPlot) index computational tools. In compound 3, cooperativity effects in π⋯π/π⋯π/π⋯π assemblies have been also analyzed. [ABSTRACT FROM AUTHOR]

The ability of amino acid-based hydrazide ligands to produce polar crystalline materials that could possess technologically important physical properties, such as ferroelectricity, is tested. Two new coordination polymers {Cu3(L1/L2)2(TPA)}n×solvent were prepared in solvothermal reaction of copper(II) ions, terephthalic acid (TPA) and amino acid-based hydrazide ligands (H2L1 = N,N′-di- L -leucine hydrazide; H2L2 = N,N′-di- L -phenylalanine hydrazide). Structural analysis showed that both coordination polymers crystallize in an enantiomorphic polar point group 1 (C1) at room temperature. The assembled coordination polymers are neutral and consist of three copper(II) ions bridged with two amino acid-based hydrazide molecules, which in turn are linked with TPA molecules to form an overall one-dimensional structure. The magnetic order in these compounds is an antiferromagnetic interaction between copper(II) ions bridged by a hydrazide (–N–N–) bridge. Thermal decomposition of the two coordination polymers begins above 480 K, confirming the high thermal stability of the amino acid hydrazide ligands. The DSC shows that both compounds undergo a reversible phase transition around 388 K. The two coordination polymers show electrical conductivities of less than 10−10 S cm−1, with no change in the real part of the dielectric constant throughout the studied temperature range. Since both compounds crystallize in the ferroelectric space group, the occurrence of spontaneous polarization was tested by polarization–voltage hysteresis experiments. [ABSTRACT FROM AUTHOR]

The hexatopic ligands 1,3,5-tris(4,2′:6′,4′′-terpyridin-4′-yl)benzene (1), 1,3,5-tris(3,2′:6′,3′′-terpyridin-4′-yl)benzene (2), 1,3,5-tris{4-(4,2′:6′,4′′-terpyridin-4′-yl)phenyl}benzene (3), 1,3,5-tris{4-(3,2′:6′,3′′-terpyridin-4′-yl)phenyl}benzene (4) and 1,3,5-trimethyl-2,4,6-tris{4-(3,2′:6′,3′′-terpyridin-4′-yl)phenyl}benzene (5) have been prepared and characterized. The single crystal structure of 1·1.75DMF was determined; 1 exhibits a propeller-shaped geometry with each of the three 4,2′:6′,4′′-tpy domains being crystallographically independent. Packing of molecules of 1 is dominated by face-to-face π-stacking interactions which is consistent with the low solubility of 1 in common organic solvents. Reaction of 5 with [Cu(hfacac)2]·H2O (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) under conditions of crystal growth by layering resulted in the formation of [Cu3(hfacac)6(5)]n·2.8nC7H8·0.4nCHCl3. Single-crystal X-ray diffraction reveals an unusual 1D-coordination polymer consisting of a series of alternating single and double loops. Each of the three crystallographically independent Cu atoms is octahedrally sited with cis-arrangements two N-donors from two different ligands 1 and, therefore, cis-arrangements of coordinated [hfacac]− ligands; this observation is unusual among compounds in the Cambridge Structural Database containing {Cu(hfacac)2N2} coordination units in which the two N-donors are in a non-chelating ligand. [ABSTRACT FROM AUTHOR]

A series of eight novel 1D metal–organometallic networks of Cu(II)/Co(II)/Cd(II) and Zn(II) bearing the bidentate ligands 1,10′-phenanthroline (1,10′-phen) and 5,5′-dimethyl-2,2′-bipyridine (5,5′-diMe-2,2′-bipy) and terminal ligand 4-stilbazole (4-Stb) were prepared by hydrothermal synthesis and were structurally characterized by using X-ray diffraction techniques. The crystal structures comprise 1D chains built-up from the self-assembly of metal centres, chelating or monodentate nitrogen ligands and bridging 1,1′-ferrocenedicarboxylate anions (Fdc)2−. Despite the fact that such arrangements contain similar building blocks, the resulting 1D arrays display different structural topologies. The major difference in these structures stems from the different conformations of the flexible ferrocenyl dicarboxylate or from the relative orientation of such units in the resulting metal–organometallic networks. The structures of {[Cu(1,10′-phen)(Fdc)]·H2O}n (1), {[Cu(5,5′diMe-2,2′-bipy)(Fdc)]·H2O}n (2), {[Cd(5,5′diMe-2,2′-bipy)(Fdc)(OH2)]}n, (4) and {[Co(5,5′diMe-2,2′-bipy)(Fdc)]·H2O}n (8) have zig-zag-type 1D chains. In contrast, the molecular assembly of {[Co(5,5′diMe-2,2′-bipy)(Fdc)]·1.5H2O}n (3) comprises a 1D-helical chain related by a 21 screw axis. When bidentate ligands are replaced by a terminal ligand, stepped chains are afforded for isomorphous phases of Co(II)/Zn(II)-derivatives: {[Co(4-Stb)2(Fdc)(OH2)]}n (5) and {[Zn(4-Stb)2(Fdc)(OH2)]}n (6), whereas {[Cu(4-Stb)2(Fdc)]}n (7) displays a double chain from bridging dicarboxylate showing a syn–anti coordination mode to adjacent metallic centres. Further characterization by powder X-ray diffraction reveals a concomitant formation of two novel conformational supramolecular isomers in the Co(II)/Fdc/5,5′-diMe-2,2′-bipy system: 3 and 8. Additional characterization was provided by Fourier transform infrared spectroscopy, thermogravimetric analysis, solution-state differential pulse voltammetry, and by calculating the frontier orbitals. [ABSTRACT FROM AUTHOR]

Following the useful concept of energetic coordination compounds (ECC), copper(II) dicyanamide was used as a building block for the synthesis of eight new complexes. As ligands, six different N-substituted tetrazoles were applied, leading to the formation of high-nitrogen containing complexes. The obtained compounds were characterized in detail by single crystal as well as powder XRD, IR, EA, DTA, and TGA. In addition, the sensitivities towards impact and friction were determined with BAM standard techniques as well as the sensitivity towards electrostatic discharges. All compounds show moderate sensitivities (IS>6, FS>80 N) and energetic properties but differ in their polymeric structures forming polymeric chains or layers up to 3D networks. [ABSTRACT FROM AUTHOR]

By combining isoquinoline‐5‐carboxilic acid with Cu(II) ions under several different conditions, we were able to obtain novel metallorganic materials, among which two 2D coordination polymers, CP 1 and CP 2 which were also characterized by SC‐XRD. Ratio of solvents (EtOH : DMF) in the mixture employed during their synthesis has a marked effect in selecting the formation of one species or the other, which basically differ in the coordination at the Cu(II) center due to k1/k2 denticity of the carboxylate ligands. [ABSTRACT FROM AUTHOR]

A coordination polymer Cu(3-CP)3(NO3) (1) was synthesized from copper(II) sulfate and 3-cyanopyridine (3-CP) with in-situ reduction by hydroxylamine sulfate via the solvent evaporation method at room temperature, and structurally characterized by single-crystal X-ray diffraction and elemental analysis. Complex 1 exhibits a structure formed by cationic [Cu(3-CP)3]nn+ chains and NO3− anions with abundant supramolecular interactions. Solid-state photoluminescence experiments show that complex 1 exhibits a relatively strong blue-green emission, and its possible emission mechanism was investigated in detail based on theoretical calculations. [ABSTRACT FROM AUTHOR]

This paper reports the syntheses and structural characterization of three new Cu(II) coordination polymers, namely [Cu(BAEE)(N 3 ) 2 ] ∝ ( 1 ), [Cu(BAEE)(NCO) 2 ] ∝ ( 2 ) and [Cu(BAEE)(NCS) 2 ] ∝ ( 3 ), where BAEE is 1,2-bis(2-aminoethoxy)ethane. Compound 1 is a one-dimensional (1D) single-stranded normal helical structure, while compounds 2 and 3 are extraordinary single-stranded meso-helical polymers. The influence of pseudohalides in these systems is observed as the azide ions are cis coordinated in 1 and the thiocyanate ions are trans coordinated in 3 , while alternate metal centers are either cis or trans coordinated with cyanate ions in 2 . These geometrical preferences play a crucial role in the diverse helicity in these chain structures, where the cis arrangement (in 1 ) favors a uniform helicity in the structure and the trans arrangement (in 2 and 3 ) of the pseudohalide ligands around the copper(II) center brings meso-helicity in the chains. The energetic difference of the cis / trans isomers and the formation energies of the different assemblies using DFT calculations suggest that the different H-bond acceptor ability of the thiocyanate ion determines the different architecture observed in 3 . Our results highlight how the geometrical preferences of the pseudohalides around the copper(II) center influence the helical diversity in these systems and thereby provide a clue toward the development of uncommon coordination polymers with amazing meso-helical character. [ABSTRACT FROM AUTHOR]

Presented here is the synthesis and property study of a novel Cu(I) compound, namely, [Cu4(2-S-Bim)7(SO4)]n·n(SO4)·n(CH3CN)·2n(H2O) (1, 2-S-Bim=2-mercaptobenzimidazole). In this compound, 2-S-Bim ligand exhibits two different coordination modes: μ2-bridging mode and terminal coordination mode. Six 2-S-Bim ligands in μ2-bridging mode combined four Cu(I) ions together, affording a [Cu4S6] cluster. The remaining two coordination sites of Cu(I) ions in the [Cu4S6] cluster are occupied by one terminal 2-S-Bim ligand and one terminal SO42− anion, thus compound 1 exhibits a 0D isolated cluster-based framework. Moreover, this compound emits intense blue luminescence at room temperature. In addition, the as-produced compound's application values against ischemia–reperfusion flaps were examined and the specific mechanism was tested simultaneously. [ABSTRACT FROM AUTHOR]

A novel coordination polymer with the chemical formula [Cu4Br(CN)(mtz)2]n (mtz = 5-methyl tetrazole) (1), has been synthesized under solvothermal conditions and characterized by elemental analysis, infrared (IR) spectroscopy, thermal gravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Interestingly, the Cu(i), CN− and mtz− in compound 1 are all generated from an in situ translation of the original precursors: Cu2+, acetonitrile and 1-methyl-5-mercapto-1,2,3,4-tetrazole (Hmnt). The in situ ring-to-ring conversion of Hmnt into mtz− was found for the first time. Structural analysis reveals that compound 1 is a novel 3D tetrazole-based Cu(i) coordination polymer, containing both metal halide cluster Cu6Br2 and metal pseudohalide cluster Cu2(CN)2 secondary building units (SBUs), which shows an unprecedented (3,6,10)-connected topology. Notably, a pseudo-porphyrin structure with 16-membered rings constructed by four mtz− anions and four copper(i) ions was observed in compound 1. The fluorescence properties of compound 1 were investigated in the solid state and in various solvent emulsions, the results show that compound 1 is a highly sensitive naked-eye colorimetric sensor for NB and 2-NT (NB = nitrobenzene and 2-NT = 2-nitrotoluene). [ABSTRACT FROM AUTHOR]

The reaction of CuI with dialkylcyanamides yielded copper(I) cluster complexes [Cu4I4(NCNR2)4] (R2 = Me2, Et2, C4H8, C5H10, C4H8O), as well as coordination polymer catena-[CuI(NCNMe2)]n. The structures of the obtained compounds were determined by single-crystal X-ray diffraction analysis, atomic emission spectroscopy (Cu), CHN elemental analysis, X-ray phase analysis, and IR spectroscopy. The prepared clusters luminesce at room temperature in the solid state with an emission maximum in the range of 554–600 nm upon irradiation at 365 nm. [ABSTRACT FROM AUTHOR]

Two architecturally dissimilar coordination complexes, namely, C1 = [CuL1(NO2)]2 and C2 = [CuL2(NO3)] (L1 = (4‐bromo‐2‐[(2‐isobutylaminoethylimino)methyl]phenolate and L2 = (4‐bromo‐2‐[(2‐propylaminoethylimino)methyl]phenolate) have been synthesized from two different organic ligand backbones. The synthesized complexes have been identified using some common techniques like elemental analysis, FT‐IR spectroscopy, and single‐crystal X‐ray analysis. The X‐ray structural analysis revealed that C1 is a dinuclear complex realized through one bridging nitrite anion, whereas for C2, nitrate anions bridge the complexes to accomplish a 1D coordination polymer. C1 and C2 when slashed down by rapid and green mechanical method by using a simple hand grinding technique, mortar and pestle, resulted in NC1 and NC2 nanoparticles, whose average size was characterized by PXRD, SEM, and DLS. As far as we know, this is the first report where the nano‐formulation has been used while maintaining the structural integrity of the Schiff base complex. The proliferative properties of these complexes have been assessed in vitro using human lung carcinoma cell line A549. Being a polymer, the number of metal centers in NC2 is much higher; accordingly, this complex is more vital in terms of biological activity in comparison with NC1. [ABSTRACT FROM AUTHOR]

The tertiary CuII/N3–/1-Mebta reaction scheme, where 1-Mebta is 1-methylbenzotriazole, led to the coordination complex [Cu(N3)2(1-Mebta)]n (1), which has an unusual 1-D corrugated tape polymeric structure built by μ-1,1 and μ3-1,1,1 end-on bridging azido groups, and terminally bound 1-Mebta ligands. Solid-state IR and UV-Vis spectra of 1 are discussed in terms of its structure. The combined results demonstrate the flexibility of both the azido and 1-Mebta groups upon coordination with 3d-metal ions, and their usefulness in the synthesis of azido-rich Cu(II) coordination polymers. [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis, characterization, molecular docking and theoretical studies of two new copper(II) [Cu2(L1)2(py)2]·H2O (1) and nickel(II) [Ni(L2)2] (2) coordination complexes, which are made through the coordination of (E)-N′-(5-bromo-2-hydroxybenzylidene) benzohydrazide (H2L1) and 1-((E)-(2-methoxyphenylimino) methyl) naphthalene-2-ol (HL2), respectively. The H2L1 and HL2 acts as deprotonated tridentate hydrazide and Schiff base ligands containing phenyl and naphthalyl groups, respectively. The molecular structure of (1) and (2) have been confirmed by single crystal X-ray diffraction studies and belongs to the monoclinic and triclinic system of the space group C2/c and P-1, respectively. The X-ray structural determination showed that the structure around Cu(II) was phenoxo-bridged distorted square pyramidal geometry for (1), while complex (2) display octahedral geometry around Ni(II). Binding affinity of (1) and (2) with the DNA generated from molecular docking was − 8.2 and − 9.2 kcal/mol, respectively, while H-pylori urease with binding affinity of − 9.3 and − 12.8 kcal/mol, respectively as predicted with Auto Dock Vina using DFT. The absorption and vibrational analysis of (1) and (2) have been carried out by the long-range corrected density functional theory (LC-DFT). The natural bonding orbital (NBO) analysis has been used to get insight into non-covalent interactions. From LC-DFT calculations, various parameters such as natural population analysis, atomic charges, and HOMO–LUMO energies have been obtained. [ABSTRACT FROM AUTHOR]

Trianionic ligands with an inner N2O2, an outer O2O2 or O2O coordination site and an oxygen atom coming from an amide function not involved in these sites yield dinuclear Cu‐Ln complexes that self‐assemble into tetranuclear species with an alternate arrangement of Cu and Ln ions. This alternate Cu‐Gd arrangement impedes Cu–Cu and Gd‐Gd interactions that could be antiferromagnetic and favours ferromagnetic Cu‐Gd interactions whose strength depends on the nature of the bridge, the phenoxo bridge made of a single oxygen atom or the amidato bridge made of three NCO atoms. Depending on the ligands, the phenoxo bridges can be single (CuOGd) or double (CuO2Gd), while the amidato bridge is always a single (CuNCOGd) bridge. A particular complex involving a trinuclear Cu‐Gd‐Cu arrangement through two amidato bridges confirms that the Cu‐Gd interaction through the amidato bridge is always weaker than the interaction through the phenoxo bridge. It has been possible to obtain complexes with an alternate Cu‐Gd arrangement involving more than two Cu‐Gd entities when two amidato bridges are present. These two amidato bridges may come from a main ligand, as in the case of tetraanionic ligands possessing two amide functions, or from two different ligands involving one amide function that are assembled by a Gd ion through their phenoxo functions. Note that the presence of auxiliary ligands with a good chelating ability for the Gd ion, such as the diketonato ligands, allows isolation of tetranuclear species only, regardless of the number of amide functions. [ABSTRACT FROM AUTHOR]

Combustion of fuels containing organosulfur compounds has resulted in the emission of sulfur oxides (SOx) into the atmosphere, therefore, causing serious environmental and health hazards. Herein, slightly distorted octahedral zig-zag 1D coordination polymer of copper(II) [Cu(4-mba)2(H2O)3] was synthesized by reacting copper sulfate pentahydrate with a carboxylate-containing ligand (H-4mba = 4-methoxybenzoic acid) and employed for sulfur compound uptake. The ligand coordinates to the copper(II) atom via two pairs of deprotonated ligating atoms (carboxylate oxygens) and two water molecules. Structural characterization also reveals that interplay of O-H···O, N-H···O, C-H···O and C-H···π interactions between lattice and coordinated water and ligands significantly contribute to the crystal packing leading to the formation and strengthening of three-dimensional supramolecular assembly. The complex, [Cu(4-mba)2(H2O)3], show potential for desulfurization of fuel with an observed adsorption capacity of 9.6 mg/g at 32°C for 6 h. DFT calculations further revealed a transfer of electron sulfur-containing compounds and the complex, [Cu(4-mba)2(H2O)3], thus leading to a stronger pi-pi interaction. [ABSTRACT FROM AUTHOR]

Two new Cu(ii) coorclination polymers [Cu(Fbtx)(H2btec)(H2O2)n and {[Cu(Fbtx)(btec)0.5(H2O2)]·H2O·}nhave been synthesised by hydrothermal reactions of Cu(ii) nitrate with 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under different pH conditions. The first complex has a two-dimensional four-connected layer structure with a 44-sql topology, whereas the second has a two-dimensional three-connected brick-wall network. The luminescence properties of the complexes in the solid state and their thermal stabilities have also been studied. [ABSTRACT FROM AUTHOR]

Green crystals of the coordination polymer (CP) [CdN3(en)(n)], 1, was obtained by reaction of CdSO4 · 5H2O with ethyl nicotinate (en) in the presence of NaN3. The structure of the CP 1 was characterized by elemental analysis, IR, 1H-NMR, UV-Visible and X-ray single crystal analysis. The ORTEP plot of CP 1 consists of [(Cd)4(N3)4(en)4(n)4] structure exhibiting 14-atom V-shaped cyclic configuration, which contains 8-atoms ring [(Cd)4(N3)4]. The structure of CP 1 creates 1D-chain where the cyclic structures are connected by two nicotinate ligands (n). The chains are extended in three directions forming 3D-network structure via extensive H-bonds. The CP 1 was tested as corrosion inhibitor for copper in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results of polarization indicated that CP 1 acts as mixed type inhibitor. Adsorption of CP 1 obeyed Langmuir adsorption isotherm. Effect of temperature on the corrosion process was studied and activation parameters were calculated and discussed. The results obtained from the two different electrochemical techniques are in good agreement. [ABSTRACT FROM AUTHOR]

The reaction of a compartmental ligand N,N′‐bis(3‐methoxysalicylidene)‐1,3‐diamino‐2‐propanol (LH3) with CuII and LnIII salts under solvothermal conditions afforded two‐dimensional coordination polymers, [{Cu5Gd2(L)2(µ3‐OH)4(NO3)4(µ‐OH2)2}(NO3)2]∞ (1) and [{Cu5Dy2(L)2(µ3‐OH)4(NO3)4(MeOH)2}(NO3)2]∞ (2). A detailed study of the magnetic properties of the two coordination polymers reveals that the [Cu5Dy2] analogue shows single‐molecule magnet (SMM) behavior with an energy barrier of about 12 K with τ0 = 10–6 s under zero‐dc field, while the [Cu5Gd2] analogue shows magnetocaloric effect with a –ΔSm value of 17.55 J kg–1 K–1 at T = 2 K (ΔB = 5 T). Interestingly, the magnetic and SMM properties of the previously reported molecular and one‐dimensional analogues containing the [Cu5Ln2] motif are preserved even in the two‐dimensional coordination networks. [ABSTRACT FROM AUTHOR]

As a contribution to a better understanding of the coordination properties of imidazolinium-dithiocarboxylate ligands towards copper, the first route towards oligonuclear copper-betaine complexes has been developed. Treatment of the coordination polymer [CuCl(Bz2ImCS2)]n (1) suspended in aceto-nitrile with thallium(I) hexafluorophosphate in different ratios affords the discrete copper(I) cluster cations [Cu4(Bz2ImCS2)4-Cl2]2+ (2) and [Cu3(Bz2ImCS2)5]3+ (3). Single-crystal X-ray diffraction of 2(PF6)2·2MeCN and 3(PF6)3·2MeCN·Et2O reveals the occurrence of unique copper-sulfur architectures. The Cu-S/Cl skeleton of 2 contains two elongated trigonal-prismatic {Cu4S2} entities which share a common {Cu4} face. In contrast, the Cu atoms of 3 define an isosceles triangle. Both compounds exhibit distorted tetrahedral copper coordination sites, based on S3Cl (within 2) and S4 (within 3) donor sets, and host dithiocarboxylate zwitterions in each of two different coordination modes. Overall, three different types of binding principles towards copper are presented here. [ABSTRACT FROM AUTHOR]

Copper(I) alkynyl complexes have attracted tremendous attention in structural studies, as luminescent materials, and in catalysis, and homoleptic complexes have been reported to form polymers or large clusters. Herein, six unprecedented structures of CuI alkynyl complexes and a procedure to measure the cone angles of alkynyl ligands based on the crystal structures of these complexes are reported. An increase of the alkynyl cone angle in the complexes leads to a modulation of the structures from polymeric [((PhC≡CC≡C)Cu)2(NH3)]∞, to a large cluster [(TripC≡CC≡C)Cu]20(MeCN)4, to a relatively small cluster [(TripC≡C)Cu]8 (Trip=2,4,6- iPr3-C6H2). The complexes exhibit yellow-to-red phosphorescence at ambient temperature in the solid state and the luminescence behavior of the Cu20 cluster is sensitive to acetonitrile. [ABSTRACT FROM AUTHOR]

Abstract. Two bis-triazole-bis-amide-based copper(II) pyridine-2,3-dicarboxylate coordination polymers (CPs), [Cu(2,3-pydc)(dtb)0.5(DMF)] ·2H2O ( 1) and [Cu(2,3-pydc)(dth)0.5(DMF)] ·2H2O ( 2) (2,3-H2pydc = pyridine-2,3-dicarboxylic acid, dtb = N, N′-bis(4 H-1,2,4-triazole)butanamide, and dth = N, N′-bis(4 H-1,2,4-triazole)hexanamide), were synthesized under solvothermal conditions. CPs 1 and 2 show similar two-dimensional (2D) structures. In 1, the 2,3-pydc anions bridge the CuII ions into a one-dimensional (1D) chain. Such 1D chains are linked by the dtb ligands to form a 2D layer. The adjacent 2D layers are extended into a three-dimensional (3D) supramolecular architecture by hydrogen-bonding interactions. The electrochemical properties of 1 and 2 were investigated. [ABSTRACT FROM AUTHOR]

Three novel bis-tetrazole ligands (1–3) containing carboxylate functional groups on the tetrazole rings and a rigid pyrazine linker unit, for the construction of coordination polymers when coordinated to copper(II) ions, were synthesised and structurally characterised. The use of pyrazine as a rigid linker between the two tetrazole units was expected to increase the dimensionality of the solid phase polymeric network of the resulting copper(II)-containing compounds. X-ray structures of the ligands revealed the effect of the substitution position on the tetrazole ring of the ester/carboxylate groups. Higher solid phase dimensionality was successfully achieved as shown by the layered two-dimensional (2-D) coordination structure being formed when the pyrazine bis-tetrazole systems were reacted with copper(II) chloride, although not in the expected manner. There was no interaction between the pyrazine nitrogen atoms and the metal ion. Computational studies showed that this was probably due to the geometry, required by the copper ion, to be involved in the close packing between the layers. The 2-D coordination polymer based on the asymmetric substituted pyrazine bis-tetrazole,[Cu(4)(H2O)](H2O)2, was further connected into a three-dimensional (3-D) coordination network through hydrogen bonding between H2O molecules. These H2O molecules were connected as a unique 1-D chain throughout the structure. Three novel bis-tetrazole ligands (1-3) containing carboxylate functional groups on the tetrazole rings and a rigid pyrazine linker unit, for the construction of coordination polymers when coordinated to copper(II) ions, were synthesised and structurally characterised. [ABSTRACT FROM AUTHOR]

Hydrothermal reaction of the requisite metal nitrate, carboxycinnamic acid (H2cca), and the long-spanning dipyridylamide bis(4-pyridylformyl)piperazine (4-bpfp) generate crystalline coordination polymers whose topology depends critically on the metal coordination geometric preference. These two new phases were structurally characterized by single-crystal X-ray diffraction. {[Cu(cca)(4-bpfp)] ·2.5H2O} n ( 1) manifests a non-interpenetrated 6-connected pcu net based on chain motifs featuring carboxylate-bridged {Cu2(OCO)2} dinuclear units, with embedded D(5) water molecule chains. {[Ni(cca)(4-bpfp)(H2O)2] ·3H2O} n ( 2) displays an acentric twofold interpenetrated 4-connected 66 dia network topology with entrapped R(4)A(1) water molecule rings. Variable temperature magnetic studies performed on 1 revealed very weak antiferromagnetic coupling within its dinuclear units. Thermal properties of these two new materials are also discussed. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry - A European Journal is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

More than 50 of layered (i.e., 2D) coordination polymers containing (CuX) clusters (X = Cl, Br, I; n = 2, 4, 5, 6, and 8) as secondary building units (SBUs) and mono- and dithioether as assembling ligands are described. This mini-review is separated into two categories; mono- (10) and dithioether (45 polymers), devoted on 2D networks. Within these 55 2D structures visited, the occurrence of the SBU motifs (CuX) where n = 2, 4, 5, 6, and 8 are dominated by the rhomboids (CuXS; 30) and the closed and open cubanes (CuIS; 16). Only 10 different other SBU motifs are found in these 2D materials (note that one polymer shares two different motifs). Some emission properties are also provided. Generally, closed cubane cluster-containing coordination polymers exhibit more intense emissions than the rhomboid dimers, which are very weakly or non-emissive. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A new bis(pyrazolecarboxylate) ligand, 1,3-phenylenebis(1 H-pyrazole-5-carboxylic acid) (H2PBPC) has been synthesized to study the structure and intriguing properties of the resultant coordination polymers synthesized under solvothermal conditions. The reaction of H2PBPC with Cu(ClO4)2 in the presence of NaOH at two different temperatures (80 and 120 °C) resulted in two coordination polymers, namely, [{Cu2Na(H2OPBPC)}]∞ ( 1) and [{Cu4Na2(H2OPBPC)2}]∞ ( 2), which display 2D corrugated sheet and 3D staircase architectures, respectively; in these structures, the aromatic C-H bond flanked by the pyrazolecarboxylate moieties was oxidized to form a C-O bond. When 2,2′-bipyridine (2,2′-bpy) was used instead of NaOH, [{Cu2(2,2′-bpy)2(H2PBPC)}(H2O)]∞ ( 3) formed, and such C-H bond activation was not observed. Interestingly, one of the coordination polymers, namely, 1, displayed catecholase and phosphatase activity. Variable-temperature magnetic susceptibility data in the range 2-300 K showed that there is antiferromagnetic coupling between the metal centers of 1 and 2 that is mediated through the phenoxo and pyrazole bridges, whereas 3 revealed dominant ferromagnetic interactions between the bis(pyrazolato)-bridged CuII centers owing to its very unusual Cu-N-N-Cu torsion angles of 75.28 and 69.52°. [ABSTRACT FROM AUTHOR]