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The hydrophobic ionic liquid N-butyl-N-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)amide (BMP-TFSA IL), which contains a series of flexible ionophores of polypyridine-type small molecules or two rigid ionophores of peripherally pyridine-modified PAMAM dendrimers, was used to extract cupric ions from aqueous solutions. The polypyridine-type ionophores show good selectivity toward cupric ions at pH 2. The selectivity is affected by the spacing between the two amino groups. However, the pyridine-modified dendrimers showed poor selectivity, although their extraction efficiency still depended on the pH of the aqueous solution. The ionic liquids that contained small molecular ionophores and their dendrimer analogs were reused after acid washing or electrochemical reduction. During acid washing, the nitrogen atoms of the ionophores were protonated to release the cupric ions into the aqueous phase, and the copper atoms were deposited onto the electrode surface during the electrochemical reduction accompanied by the regeneration of the ionophores., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Early signalling events that control the process of heavy metal-induced cell death are largely unknown in plants. In mammals protein tyrosine phosphorylation plays an important role in the activation of programmed cell death. We thus examined the involvement of tyrosine phosphorylation in Cu-induced rice cell death. This investigation demonstrates that Cu induces cell death and DNA fragmentation in rice root cells. In the presence of Cu, the level of phosphotyrosine accumulation declined in the band of 45 kDa, p45. To analyze the role of tyrosine dephosphorylation for the regulation of Cu-induced cell death more precisely, we increased levels of tyrosine phosphorylation using the protein tyrosine phosphatase inhibitor, sodium orthovanadate (Na(3)VO(4)). Treatment of rice roots with Na(3)VO(4) blocked Cu-induced cell death and protein tyrosine dephosphorylation. In addition, the antioxidant GSH and the calcium chelator EGTA significantly abolished Cu-induced cell death and protein tyrosine dephosphorylation. These results provide evidence that dephosphorylation of a tyrosine-phosphorylated protein, p45, is an important step in the Cu-triggered signalling transduction pathway.

Commercial CuNi (55/45 wt%) alloy can be electrochemically dealloyed to be the porous Cu‐rich CuNi electrodes, which reveals an enhanced catalytic activity toward nitrate reduction in contrast with that of the mother alloy electrodes. In comparison with the use of aqueous electrolytes, the formation of the porous structures is reproducible if ionic liquid (IL) is used as the electrolyte for the dealloying process. During the dealloying process, a relatively more quantity of Ni but both Ni and Cu were electrochemically oxidized to be Ni(II) and Cu(II) complex ions; different ions seemed to own different coordinating molecules in accordance with the NMR analysis. Cu(II) ions could be reduced to Cu metal and deposited upon the counter electrode during the dealloying process. Ni(II) ions, on the other hand, can be mostly removed from the IL phase by extraction into the immiscible water phase. A sustainable system may be developed for the preparation of nitrate‐active electrodes in accordance with the study shown here. [ABSTRACT FROM AUTHOR]

The hydrophobic ionic liquid N-butyl- N-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)amide (BMP-TFSA IL), which contains a series of flexible ionophores of polypyridine-type small molecules or two rigid ionophores of peripherally pyridine-modified PAMAM dendrimers, was used to extract cupric ions from aqueous solutions. The polypyridine-type ionophores show good selectivity toward cupric ions at pH 2. The selectivity is affected by the spacing between the two amino groups. However, the pyridine-modified dendrimers showed poor selectivity, although their extraction efficiency still depended on the pH of the aqueous solution. The ionic liquids that contained small molecular ionophores and their dendrimer analogs were reused after acid washing or electrochemical reduction. During acid washing, the nitrogen atoms of the ionophores were protonated to release the cupric ions into the aqueous phase, and the copper atoms were deposited onto the electrode surface during the electrochemical reduction accompanied by the regeneration of the ionophores. [ABSTRACT FROM AUTHOR]

Abstract: The voltammetric behavior of cuprous ions has been studied at disk electrodes of glassy carbon and polycrystalline platinum in a new hydrophilic 1-butyl-3-methylimidazolium salicylate ionic liquid (BMI-SAL IL). Cuprous ions Cu(I) were introduced into the IL by the anodic dissolution of a Cu wire electrode or by the addition of CuCl. This air- and water-stable hydrophilic IL is very similar to dicyanamide (DCA)-based ILs because both DCA anions and salicylate (SAL) anions have very strong ligand properties; therefore, many metal salts, such as metal halides, are very soluble in this IL. However, the source of SAL anions, sodium salicylate, is considerably cheaper than sodium dicyanamide salt. The potentiostatic electrodeposition of copper onto iron substrates has also been investigated in this study. The surface morphologies of the copper deposits were significantly altered by the electrodeposition potential; granular, mirror-like, and porous copper deposits could be obtained at different negative potentials. The activity of the copper deposit-modified iron electrodes toward the electrochemical nitrate reduction in alkaline solutions was found to significantly depend on the surface morphologies. The granular and the porous surfaces showed better activities. The mirror-like surface, however, had no activity on the electrochemical nitrate reduction. [Copyright &y& Elsevier]

Cu and CuPb electrodes were prepared via electrodeposition from a hydrophobic protic amide-type ionic liquid, the protonated betaine bis((trifluoromethyl)sulfonyl)amide ([Hbet][TFSA]), and water mixture containing CuO/PbO as the metal sources under ambient air rather than inert atmosphere. The possible coordination structure and the voltammetric behavior of the metal ions were carefully studied. The electrodeposited Cu electrodes showed steady activity towards nitrate reduction, and the activity depended on the electrodeposition potential. The dependence might be due to the change of surface morphologies of Cu with the electrodepositing potentials. The activity was markedly enhanced once Pb was doped into the electrodeposits (CuPb). The bulk electrolysis of nitrate indicated that the key step nitrite formation occurred during the electrocatalytic reduction, and nitrite could be further reduced to other nitrogen species. The electrodeposited CuPb electrodes exhibited the potential to be used as the electrocatalysts of nitrate reduction and/or nitrate sensor. Image 1 • CuO and PbO were dissolved in a protic hydrophobic amide-type ionic liquid (IL). • Electrochemical and spectroscopic features of Cu(II) and Pb(II) were studied. • Potentiostatic electrodeposition was used to prepare Cu and CuPb electrodes. • Both electrodes showed electrocatalytic activity towards nitrate reduction. • Pb doping significantly altered the surface morphologies and reaction current. [ABSTRACT FROM AUTHOR]

[Display omitted] • SPNC with Cu 2 O/Cu(OH) 2 surface and (1 3 ¯ 2) high-index facet is successfully synthesized. • SPNC shows 31.10 m2 g−1 for surface area and successfully catalyze CO 2 RR. • SPNC shows remarkable selectivity (FE C2H4 = 55.3 %) for the production of C 2 H 4. • Cu 2 O/Cu(OH) 2 surface impact significantly on CO-CO dimer for production of C 2 H 4. In the production of C 2 H 4, a vital raw material in the synthesis of polyethylene and polyvinyl chloride, Cu 2 O is a highly promising catalyst with excellent Faradaic efficiency and selectivity. We propose a method involving the partial reduction of Cu(OH) 2 to Cu 2 O by sodium L-ascorbate for the synthesis of spherical and porous Cu 2 O nanocages (SPNCs) with a surface containing both Cu 2 O and Cu(OH) 2. High-resolution transmission electron microscopy and electron diffraction measurements revealed ∼ 3-nm pores and a (1 3 ¯ 2) high-index facet on the SPNC, respectively. As SPNCs have a porous structure, their specific surface area is greater (31.10 m2 g−1) than that (6.35 m2 g−1) of spherical Cu 2 O nanocrystals (SNCs) with solid interiors. Furthermore, SPNCs, when applied as electrocatalysts for catalysing the CO 2 reduction reaction (CO 2 RR), demonstrated remarkable mass activities (16.92 mA mg−1 at −1.15 V vs. reversible hydrogen electrode) for C 2 H 4 production, with a Faraday efficiency reaching an impressive 55.3 %. Stability test data showed a consistent CO 2 RR current density over 6 h, owing to the porous structure and the presence of both Cu(OH) 2 and Cu 2 O on the catalyst surface. Our proposed SPNC catalysts can be employed as effective CO 2 RR catalysts for producing C 2 H 4 , which may help in reducing the present reliance on petrochemical processes. [ABSTRACT FROM AUTHOR]

With the development of the artificial intelligence (AI) industries, electronic packaging is developing in the direction of high-density, high efficiency and multi-functionality. To realize the high density and tiny scale interconnection, application of microbumps is inevitable. Thus, the mechanical and thermal properties of intermetallic compounds (IMCs) become quite important as the proportion of IMC in the bump is greatly increased. In this study, three types of full IMCs bump, Cu/Sn-3.5Ag(SA)/Cu, Cu18Ni/SA/Cu and Cu18Ni18Zn/SA/Cu, were fabricated through transient liquid phase (TLP) bonding. The evolution of orientation and the sizes of the Cu 6 Sn 5 grain before and after long-term thermal aging were analyzed and compared. After long-term thermal aging, the full IMCs bump with Ni and Zn added into Cu substrate simultaneously maintained consistent structure. In addition, the unusual growth of network-like Cu 3 Sn was observed in Cu18Ni/SA/Cu. Furthermore, the mechanical test and fracture cross-section analysis were conducted to discuss the crack paths. The study focused on establish the correlation between microstructure and mechanical performance. Network-like Cu 3 Sn was considered to enhance the strength of interfaces. Finally, the full IMCs bump which demonstrated the extraordinary thermal stability provided a reliable microstructure for application. • The microstructure and shear performance of Cu/Sn3.5Ag/Cu, Cu-Ni/Sn3.5Ag/Cu and Cu-Ni-Zn/Sn3.5Ag/Cu full intermetallic structure were revealed. • The employment of Cu-Ni-Zn matrix can inhibit the formation of Cu 3 Sn layer after long-term thermal aging, showing good thermal stability. • The growth of network-like Cu 3 Sn only formed after aging, which enhances the strength of the interface between Cu 6 Sn 5 and Cu 3 Sn. • The correlation between fracture paths and grain structure is established. [ABSTRACT FROM AUTHOR]

[Display omitted] • Size of polyhedral Cu nanoparticles (NPs) shrank once Cd was introduced. • Size shrink was accompanied with evident activity promotion to nitrate reduction. • Mismatch between the two metal lattices might cause the size shrink. • Rate determining step for CuNPs and CuCdNPs was probably different. • Size or synergistic (CuCd bimetal) effect needs to be further studied. Polyhedral copper nanoparticles (CuNPs) were potentiostatically electrodeposited upon stainless-steel from a hydrophobic protic amide-type ionic liquid (IL), i.e. protonated-betaine bis((trifluoromethyl)sulfonyl)amide ([Hbet][TFSA]) containing CuO as the precursor. The surface morphologies and electrocatalytic activities of the CuNPs towards nitrate reduction were significantly altered after the co-deposition of cadmium (Cd). The variation of morphology and activity was caused by the significant shrinkage of the particle size as a result of the Cd co-deposition and the synergistic effect of Cu and Cd bimetal. In the galvanostatic electrolysis of nitrate, CuNPs showed a much higher reductive overpotential in comparison with CuCdNPs. It might be caused by a kinetic hindrance for the CuNPs in the rate-determining step of nitrate reduction (i.e. formation of nitrite ion NO 2 −). CuCdNPs, however, exhibited the robust and stable activity in which the rate-determining step was determined as a two-electron transfer reaction in accordance with the Tafel slope. [ABSTRACT FROM AUTHOR]

Abstract: Extraction of Cu(II) from neutral aqueous solutions with the hydrophobic room-temperature ionic liquid (IL) N-butyl-N-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide (BMP-TFSI) in the presence of the pyridine-based ionophore N 1,N 1,N 4,N 4-tetrakis(2-(pyridin-2-yl)ethyl)butane-1,4-diamine (C4N2Py4) is demonstrated in this study. Although the distribution coefficients, D M, of Cu(II) extraction depend on the concentration of Cu(II) in aqueous solutions, all values were higher than 200, indicating extremely high extraction efficiency. Based on spectrophotometric, electrochemical, and X-ray crystallography studies, the coordination number of the C4N2Py4-coordinated Cu(II) ions was determined as 2. The voltammetric behavior of Cu(I), Cu(II), and their C4N2Py4 complex ions were also studied. The recovery of Cu from the IL was conducted by washing the IL phase containing the extracted Cu(II) complex with an acidic aqueous phase or by controlled-potential electrolysis. The IL containing C4N2Py4 was employed for two complete rounds and a decrease in extraction efficiency was only observed when higher concentration of Cu(II) was used. [Copyright &y& Elsevier]

Abstract: The reaction of [Cu(NCMe)4](BF4) with equimolar amounts of the tris(substituted-pyrazolyl)methane ligand HCPz3 or HC(3,5-Me2Pz)3 yields the respective salts [Cu(HCPz3)(NCMe)](BF4) (1a) or [Cu(HC(3,5-Me2Pz)3)(NCMe)](BF4) (1). The acetonitrile ligand of 1 can be replaced by prazine, 4,4′-dipyridine or 1,4-diisocyanobenzene to yield related mononuclear complexes [Cu(HC(3,5-Me2Pz)3)(pyrazine)](BF4) (2), [Cu(HC(3,5-Me2Pz)3)(4,4′-bipyridine)] (BF4) (3) or [Cu(HC(3,5-Me2Pz)3)(1,4- CNC6H4NC)](BF4) (7), respectively. A series of binuclear copper(I) complexes {[Cu(HC(3,5-Me2Pz)3)]2(μ -BL)}(BF4)2 (4, BL=pyrazine; 5, BL=4,4′-dipyridine; 8, BL=1,4-diisocyanobenzene) were prepared by treating equal molar ratio of 1 with related mononuclear complexes 2, 3 and 7. In addition, binuclear copper(I) complexes were also prepared from treatment of 2equiv of 1 with the related bridge ligand. Both of 4 and 5 reformed mononuclear starting complex 1 in acetonitrile solution. However, the more robust complex 8 was stable in acetonitrile solutions. The structure of complexes 1a, 4, 5, and 7 were confirmed by X-ray crystallography. The redox properties of 4 and 8 were examined by cyclic voltammetry and exhibited two quasi-reversible waves suggesting that no significant structural reorganization occurs during the redox process on the electrochemical time scale. [Copyright &y& Elsevier]