Assembly Of Cu Research Articles

Supramolecular assemblies of Cu(II) with a tetraphenylethene-imidazole ligand for tuning photocatalytic CO2 reduction.

Cu(II) supramolecular assemblies [Cu2(tipe)2(H2O)2](NO3)4·2.5H2O (CuN4) and [Cu2Cl4(tipe)(CH3CN)]·H2O (CuN2Cl2) (tipe = 1,1,2,2-tetrakis(4-(imidazole-1-yl)phenyl)ethene) were synthesized and utilized for photocatalytic CO2 reduction. CuN4 exhibits CO production of up to 891 μmol gcat-1 with a selectivity of 79.9%, while CuN2Cl2 gives low CO production of 206 μmol gcat-1 but with a high selectivity of >99.9% in 5 h. The experimental and DFT calculation results indicate that the coordination environment and non-covalent interactions within the assemblies have a great impact on the photocatalytic CO2 reduction behavior. This work provides useful insights on Cu(II) assembly catalyzed CO2 photoreduction.

Viscose Support for Assembly of Cu2O and TiO2: Antimicrobial, Photocatalytic, and Recoverable Composites for Cr(VI) Removal

Viscose Support for Assembly of Cu₂O and TiO₂: Antimicrobial, Photocatalytic, and Recoverable Composites for Cr(VI) Removal

Nanoporous Coral Cluster‐Like Copper Metal‐Organic Framework as an Efficient Anode for Lithium‐Ion Batteries

AbstractOwing to the rich redox functionalities and numerous pore structure, metal‐organic frameworks (MOFs) are directly emerging as prospective electrode materials with special properties. In the present study, exotic and unique nanomaterials of copper‐based metal‐organic framework (Cu‐MOF‐74) were successfully prepared by coordination assembly of Cu (II) and 2,5‐dihydroxyterephthalic acid (DHTA) through the solvothermal route and served as anode materials for lithium‐ion batteries for the first time. The Cu MOF has a coral cluster‐like nanoporous morphology composed of hexagonal columns with a length of 3.0 μm and a radius of 132 nm. When tested as anode, it achieved a high reversible capability of 870.3 mA h g−1 at 100 mA g−1, remarkable rate performance (up to 1000 mA h g−1) and a long service life (300 cycles) in the dis‐/charge process. Such outstanding properties of the MOF anode may be mainly ascribed to the conjugated ligand moiety and the particular microstructural features. The results of this study provided insights for the rational design of primitive MOFs for advanced lithium storage.

Schiff Bases Functionalized with T-Butyl Groups as Adequate Ligands to Extended Assembly of Cu(II) Helicates.

The study of the inherent factors that influence the isolation of one type of metallosupramolecular architecture over another is one of the main objectives in the field of Metallosupramolecular Chemistry. In this work, we report two new neutral copper(II) helicates, [Cu2(L1)2]·4CH3CN and [Cu2(L2)2]·CH3CN, obtained by means of an electrochemical methodology and derived from two Schiff-based strands functionalized with ortho and para-t-butyl groups on the aromatic surface. These small modifications let us explore the relationship between the ligand design and the structure of the extended metallosupramolecular architecture. The magnetic properties of the Cu(II) helicates were explored by Electron Paramagnetic Resonance (EPR) spectroscopy and Direct Current (DC) magnetic susceptibility measurements.

3D supramolecular assembly of Cu(II) CP containing 1D zig-zag chain and 2D paddle-wheel net: Structural elucidation and investigation of band gap

A new Cu(II) based coordination polymer (CP) [Cu3(ipa)3(4-clpy)(H2O)2][Cu(ipa)(4-clpy)2(CH3OH)]·3CH3OH (1); (H2ipa = isophthalic acid or benzene-1,3-dicarboxylic acid and 4-clpy = 4-chloropyridine) has been synthesized by slow diffusion method in a single pot technique. Single crystal X-ray analysis reveals that compound 1 consists of both one-dimensional (1D) zig-zag chain and two-dimensional (2D) paddle-wheel net, resulting the formation of a three-dimensional (3D) supramolecular architecture via extensive hydrogen bonding, π⋯π stacking and halogen⋯π interactions. The strength of non-covalent interactions in compound 1 has been investigated by Hirshfeld surface analysis. The semiconducting nature of compound 1 was also explored by HOMO-LUMO band-gap calculation using density functional theory (DFT) computation.

Diphosphine modified copper(I)-thiacalixarene supramolecular structure for effective photocurrent response and photodegradation of methylene blue

In this paper, a diphosphine ligand modified copper(I)-thiacalixarene compound, [Cu2(TC4A)(dppm)]·2H3O+·2MeCN (1) (H4TC4A = p-tert-butylthiacalix[4]arene, dppm = 1, 1-bis(diphenylphosphine)methane), was obtained by the assembly of Cu(OAc)2·H2O, H4TC4A and dppm in a mixed solution of acetonitrile and dichloromethane. Compound 1 was well defined. Single crystal X-ray diffraction analysis shows the central skeleton of 1 has two copper atoms, one TC4A4− ligand and one dppm ligand. Compound 1 was characterized by 1H and 31P NMR, Fourier transform infrared (FT-IR), X-ray photoelectron (XPS), ultraviolet–visible (UV–Vis) absorption and diffuse reflection spectra, together with thermogravimetric (TG) analysis. Furthermore, the luminescence, photocurrent response characteristic, photocatalytic performance and electrochemistry of 1 have been investigated. Compound 1 has better photo-induced electron/hole pair generation and separation efficiency in an FTO electrode. The degradation rate of methylene blue (MB) with the addition of 1 was approximately 88%, which was significantly higher than that without the catalyst within 300 min. These results indicate that compound 1 has good light-emitting and photoelectric properties and will be a potential semiconductor material.

3d Supramolecular Assembly of Cu(Ii) Cp Containing 1d Zig-Zag Chain and 2d Paddle-Wheel Net: Crystal Structure Determination and Band Gap Study

3d Supramolecular Assembly of Cu(Ii) Cp Containing 1d Zig-Zag Chain and 2d Paddle-Wheel Net: Crystal Structure Determination and Band Gap Study

Assembly of Cu–In–Sn–Se quantum dot–sensitized TiO2 films for efficient quantum dot–sensitized solar cell application

Ternary I-III-VI (such as CuInSe2 and AgInS2) quantum dots (QDs) have been increasingly studied in the field of photoelectric conversion applications. Here, we prepare a relatively less toxic Cu–In–Sn–Se (CISSe) QD by an organic high-temperature hot injection method, and this material is subsequently applied as a functional sensitizer to produce QD-sensitized solar cells (QDSSCs). Because of the effect of Sn doping and ZnS passivation, the TiO2/CISSe/ZnS photoanode obtains the greatest composite resistance (985.5 Ω·cm2) and highest electron lifetime (120.23 ms) among the experimentally compared materials, showing the further inhibition of charge recombination when compared with bare Cu–In–Se solar cells while effectively enhancing the collection efficiency of photogenerated electrons. Using CISSe/ZnS QDs as a sensitizer, the power conversion efficiency of the QDSSC reaches 6.7%, of which Voc, Jsc, and FF reach 0.559 V, 22.93 mA/cm2, and 0.52, respectively. It provides a new possibility for the development of QDSSCs.

In-situ growth and fabrication of metal-organic charge transfer complex nanowire devices with controlled diameter using dielectrophoretic force

Ultrathin Cu:TCNQ (Cu-tetracyanoquinodimethane) nanowires (∼10–50 nm diameter) are interesting from a fundamental point of view to study electrical as well as opto-electronic transport and also held promising interest in nanoelectronics, particularly for photodetector applications. Dielectrophoresis-based device fabrication from an aqueous solution is useful and has some potential applications. However, such device fabrication may degrade material property. Herein, we demonstrate directed in-situ growth and assembly of Cu:TCNQ nanowire at predefined electrodes in vacuum using dc dielectrophoresis. The mechanistic understanding of the process is verified by COMSOL Multiphysics simulation. The externally applied electric field also exploits to control over the number as well as diameter of the nanowire during growth. Field grown nanowires bridging two electrodes are structurally characterized using a unique challenging technique with Transmission Electron Microscope. The field-grown nanowires are found to have better electrical performance compared to normal growth.

Structurally characterized copper-chrysin complexes display genotoxic and cytotoxic activity in human cells

The scientific interest in the development of novel anticancer metallodrugs with improved clinical efficiency and pharmacological properties based on a variety of metal ions and naturally derived products as biological ligands, is continuous and rising. Herein, we present the synthesis, full structural and physico-chemical characterization of two heteroleptic complex assemblies of Cu(II) with chrysin and the anchillary aromatic chelators 1,10-phenanthroline and 2,2́-bipyridine. The complexes constitute the only crystallographically characterized structures with Cu(II) as the metal core and flavonoid chrysin as the ligand. The frequency of sister chromatid exchanges (SCEs) was measured as an indicator of genotoxicity while the proliferation rate index (PRI) and mitotic index (MI) were estimated as indicators of cytostatic effect. In addition, cytotoxicity studies through resazurin assay were employed against two human lung cancer cell lines. Our results indicate significant cytotoxic and genotoxic activity of the novel heteroleptic Cu(II)-chrysin complexes that merit further investigation of their pharmacological profile.

Ultrafast Growth of a Cu(OH)2–CuO Nanoneedle Array on Cu Foil for Methanol Oxidation Electrocatalysis

A swift potentiostatic anodization method for growing 5-7 µm tall nanoneedle array of Cu(OH)2-CuO on Cu foil within 100 s has been developed. This catalytic electrode when screened for methanol oxidation electrocatalysis in 1 M KOH with 0.5 M methanol, delivered a current density as high as 70 ± 10 mA cm-2 at 0.65 V vs. Hg/HgO which is superior to the performance of many related catalysts reported earlier. Observed activity enhancement is attributed to the formation of both Cu(OH)2-CuO nanoneedle array of high active surface area over the metallic Cu foil. In addition, Cu(OH)2-CuO/Cu electrode had also exhibited excellent stability upon prolonged potentiostatic electrocatalytic oxidation of methanol while retaining the charge transfer characteristics. Growth of such highly ordered assembly of Cu(OH)2-CuO nanoneedles has never been achieved before within a minute. When compared to its OER activity, the addition of 0.5 M methanol has lowered the overpotential at 10 mA cm-2 by 334 mV which is significant. This encourages the use of methanol as a sacrificial anolyte for energy-saving production of H2 from water electrolysis.

Anion-directed assemblies of Cu(II) mono, di, and poly-nuclear coordination compounds with a 32-membered azacrown ligand: Synthesis, characterisation and crystal structures

A novel 32-membered azacrown ligand L was synthesized from the [2 + 2] condensation between 2-[3-(2-formylphenoxy)-2-hydroxy propoxy]benzaldehyde and 1,2-diaminopropane by following in situ reduction. Three metal-organic coordination compounds [CuL(NCS)]NO3·CH3OH (1), [Cu2L(CH3COO)4].0.5H2O (2), and [CuL(μ-Cl)(NO3)]n.2nCH3CN (3), were prepared from reaction of L with copper(II) salts containing different anions. Depending on the reaction controlling factor, i.e. NCS−, CH3COO−, NO3−, and Cl− anions, mono, di and polynuclear metal-organic coordination compounds were constructed. Complexes were characterized by spectroscopic methods and single crystal X-ray diffraction. Crystal structures indicate that L in presence of NCS− and Cu(NO3)2·3H2O forms mononuclear complex 1. Dinuclear complex 2 was formed by the reaction of L in presence of Cu(CH3COO)2·2H2O. Reaction of Cu(NO3)2·3H2O and CuCl2·3H2O with L give rise complex 3 which is a 1-dimensional coordination polymer. The coordination polymer constructed from distorted octahedron shaped copper nucleus that are exomacrocylic in which two Cl atoms serve as bridge. Potentially decadentate ligand, L, with four N- and six O-donor sites in presence of Cu(II) salts reacts only with its N-donors. Complexes 1 and 3, both, are crystalized in a centrosymmetric space group P21/c and dinuclear complex 2 is crystalized in a polar space group P21.

Synthesis, physicochemical characterization and biological properties of two novel Cu(II) complexes based on natural products curcumin and quercetin

Curcumin and quercetin are two of the most prominent natural polyphenols with a diverse spectrum of beneficial properties, including antioxidant, anti-inflammatory, chemopreventive and chemotherapeutic activity. The complexation of these natural products with bioactive transition metal ions can lead to the generation of novel metallodrugs with enhanced biochemical and pharmacological activities. Within this framework, the synthesis and detailed structural and physicochemical characterization of two novel complex assemblies of Cu(II) with curcumin and quercetin and the ancillary aromatic chelator 2,2′-bipyridine is presented. The two complexes represent the only crystallographically characterized structures with Cu(II) as the central metal ion and curcumin or quercetin as the ligands. The new complexes were biologically evaluated in vitro for their antioxidant potential, both exhibiting strong scavenging activity in the 2,2-diphenyl-1-picrylhydrazyl assay, and their plasmid DNA binding/cleavage properties. Both complexes appear to be non-toxic in the eukaryotic experimental model Saccharomyces cerevisiae and merit further investigation of their pharmacological profile.

Cu(II)-Regulated On-Site Assembly of Highly Chemiluminescent Multifunctionalized Carbon Nanotubes for Inorganic Pyrophosphatase Activity Determination.

A novel signal-on chemiluminescence (CL) assay for pyrophosphatase (PPase) activity determination was innovatively developed based on the Cu(II)-regulated on-site assembly of highly chemiluminescent Cu(II), N-(aminobutyl)-N-(ethylisoluminol) (ABEI), gold nanodot, and chitosan multifunctionalized carbon nanotubes (Cu(II)/ABEI-Au/cs-CNTs). First, ABEI-functionalized gold nanodots (ABEI-Au) were assembled on the surface of chitosan-modified carbon nanotubes (cs-CNTs) via the reduction of HAuCl4 with ABEI in a cs-CNT suspension to form ABEI-Au/cs-CNTs. Then, it was found that the catalyst Cu(II) can be selectively, efficiently, and quickly adsorbed onto ABEI-Au/cs-CNTs via the high-affinity interactions between Cu(II) and cs-CNTs to form novel hybrid nanomaterials Cu(II)/ABEI-Au/cs-CNTs. The CL intensity of Cu(II)/ABEI-Au/cs-CNTs was enhanced by about 2 orders of magnitude compared with that of ABEI-Au/cs-CNTs. Furthermore, it was found that in the presence of pyrophosphate ions (PPi), PPi could coordinate with Cu(II) to form a stable PPi-Cu(II) complex and block the assembly of Cu(II)/ABEI-Au/cs-CNTs. After the addition of PPase, PPase could catalyze the hydrolysis of PPi into Pi and release Cu(II) from the PPi-Cu(II) complex. The released free Cu(II) could trigger the on-site assembly of highly chemiluminescent Cu(II)/ABEI-Au/cs-CNTs, resulting in an enhanced CL intensity. The enhanced CL intensity had a good linear relationship with the activity units of PPase ranging from 0.025 to 0.5 U, with a detection limit of 9 mU. The method was employed to monitor the PPase inhibitor efficiently. Cu(II)/ABEI-Au/cs-CNTs with excellent CL may also find more applications in the development of novel CL analytical methods.

Synthesis, crystal structure and magnetic property of a 3D Cu-organic framework

The assembly of Cu(II) ion and a multidentate pyridine-azole ligand 3-(tetrazol-5-yl)-5-(pyrid-2-yl)-1,2,4-triazole (H2TPT), has resulted in an interesting 3D non-interpenetrating metal-organic framework, [Cu(TPT)]n (1). Compound 1 crystallizes in chiral P41212 space group with Flack parameter of −0.0268. The linkage of tetrazole groups of deprotonated TPT and Cu(II) centers generates the right-hand helical chains, and adjacent chains are further connected with each other, giving rise to a 3D intricate architecture. The compound was characterized by single-crystal X-ray diffraction, thermogravimetric analysis, elemental analysis, infrared spectroscopy and powder X-ray diffraction analysis. Moreover, the magnetic property of compound 1 has been investigated.

Pseudohalide-directed assemblies of Cu(II) coordination polymers with diverse structures and dye adsorption behaviors

Assembly of 3,4-bis(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (L334) and CuBr2 without or with the presence of thiocyanate (SCN−)/dicyanamide [dca, N(CN)2−] anion produces three Cu(II) coordination polymers, {[Cu(L334)(H2O)2](Br)2(CH3OH)}n (1), {[Cu(L334)(SCN)2(H2O)](H2O)(EA)}n (2) (EA = ethyl acetate), and [Cu(L334)(dca)2]n (3). The crystal structures for 1 and 3 show different 2D layered coordination networks, whereas that for 2 represents a distinct 1D coordination pattern. The above results demonstrate that the addition of pseudohalide anions plays an important role in structural construction of coordination architectures. Moreover, 1 exhibits the best adsorption capacity toward methyl orange (MO) dye.

Assembly of Cu(I) Alkynyl Complexes: From Cluster to Infinite Cluster-Based Framework

Variation of the reaction conditions with Cu powder, Cu(NO3)2, and tBuC≡CH as starting materials afforded three new Cu(I) alkynyl complexes, namely, [Cu14(tBuC≡C)10(NO3)4(MeOH)2]·H2O (1), Cu15(tBuC...

Facile synthesis and antibacterial applications of cuprous oxide/bovine serum albumin hierarchical nanocomposite particles

A facile method to prepare cuprous oxide/bovine serum albumin (Cu2O/BSA) hierarchical nanocomposite particles (NCPs) through imitating biomineralization is presented. BSA acted as the structure-directing agents, guiding the nucleation, growth and assembly of Cu(OH)2 at binding sites to construct the hierarchical structure and then Cu2O/BSA NCPs were achieved. The synthesized nanocomposite with hierarchical structure exhibited excellent antibacterial performance. The products obtained were characterized with XRD, TEM, FTIR, EDX and XPS to investigate the formation mechanism of Cu2O/BSA hierarchical structure. Cu2O/BSA NCPs with size of 20–50 nm built up by several 6–7 nm Cu2O nanocrystals with BSA showed better antibacterial performance in the comparative experiments, which was attributed to the special structure and good biocompatibility of the Cu2O/BSA NCPs. And the possible mechanism was presented to explain the excellent antibacterial properties of Cu2O/BSA NCPs.

Supramolecular assembly of Cu(II)-based 1D coordination polymer: Synthesis, characterization and correlation of band gap

A Cu(II) based one-dimensional coordination polymer (1D CP) [Cu(nip)(4-clpy)2] (1), (H2nip = 5-nitroisophthalic acid and 4-clpy = 4-chloro pyridine)has been designed and well characterized by elemental analysis, infrared spectrum, single crystal X-ray diffraction (SCXRD) technique, powder X-ray diffraction (PXRD) pattern and thermogravimetric analysis (TGA). The 1D CP contains 16-member metal-ligand chelate ring which exhibits interesting Cl···π(chelate) interaction. This secondary interaction plays important role in supramolecular assembly in the crystal structure. The optical band gap has been determined and correlated with the theoretical band gap obtained by density functional theory (DFT) computation. The band gap value reveals that the compound 1 possesses semiconducting property. Photophysical property of 1 has also been examined by fluorescence and life time study.

Supramolecular organization and structure of Cu(II) and Ni(II), 2,2′-bipyridine cations with tartratogermanate anions

This study describes supramolecular assemblies of Cu(II) and Ni(II) 2,2′-bipyridine cations with dimeric tartratogermanate anions, namely [CuCl(bipy)2]2[Ge2(OH)2(Tart)2]·4H2O (I) and [Ni(bipy)3]4[{Ge2(OH)2(Tart)2}3Cl2]·15H2O (II). The compounds were characterized by elemental analysis, mass-spectrometry, IR-spectroscopy and X-ray analysis. The chloride ion coordinates to the Cu atom in cation I and two chloride ions together with the [Ge2(OH)2(Tart)2]2− anion neutralize the charge of the cation in II. The coordination polyhedra of the Ge atoms are trigonal bipyramids in the structures of I and II. The coordination polyhedra of two symmetrically independent [CuCl(bipy)2]1+ cations are distorted trigonal bipyramids in the structure of I, whilst the coordination polyhedra of the Ni cations in II are octahedral.