Visualizing Biological Copper Storage: The Importance of Thiolate-Coordinated Tetranuclear Clusters

Bacteria possess cytosolic proteins (Csp3s) capable of binding large quantities of copper and preventing toxicity. Crystal structures of a Csp3 plus increasing amounts of Cu^I provide atomic-level information about how a storage protein loads with metal ions. Many more sites are occupied than Cu^I equiv added, with binding by twelve central sites dominating. These can form [Cu₄(S-Cys)₄] intermediates leading to [Cu₄(S-Cys)₅]⁻, [Cu₄(S-Cys)₆]²⁻, and [Cu₄(S-Cys)₅(O-Asn)]⁻ clusters. Construction of the five Cu^I sites at the opening of the bundle lags behind the main core, and the two least accessible sites at the opposite end of the bundle are occupied last. Facile Cu^I cluster formation, reminiscent of that for inorganic complexes with organothiolate ligands, is largely avoided in biology but is used by proteins that store copper in the cytosol of prokaryotes and eukaryotes, where this reactivity is also key to toxicity.     

Visualizing Biological Copper Storage: The Importance of Thiolate‐Coordinated Tetranuclear Clusters

Bacteria possess cytosolic proteins (Csp3s) capable of binding large quantities of copper and preventing toxicity. Crystal structures of a Csp3 plus increasing amounts of Cu^I provide atomic‐level information about how a storage protein loads with metal ions. Many more sites are occupied than Cu^I equiv added, with binding by twelve central sites dominating. These can form [Cu₄(S‐Cys)₄] intermediates leading to [Cu₄(S‐Cys)₅]⁻, [Cu₄(S‐Cys)₆]²⁻, and [Cu₄(S‐Cys)₅(O‐Asn)]⁻ clusters. Construction of the five Cu^I sites at the opening of the bundle lags behind the main core, and the two least accessible sites at the opposite end of the bundle are occupied last. Facile Cu^I cluster formation, reminiscent of that for inorganic complexes with organothiolate ligands, is largely avoided in biology but is used by proteins that store copper in the cytosol of prokaryotes and eukaryotes, where this reactivity is also key to toxicity.     

Synthesis,spectroscopic characterization,and crystal structures of copper(I) iodide clusters of N-methylthiourea and 1,3-diazinane-2-thione

Two copper(I) iodide complexes, [Cu₄(Metu)₆I₄] (I) and [Cu₈(Diaz)₁₂I₈] (II) (Metu = N-methylthiourea; Diaz = 1,3-diazinane-2-thione), have been prepared and their structures been determined by X-ray crystallography. The crystal structures show that complex I is a tetranuclear, while II is an octanuclear cluster, both having a Cu : S ratio of 2 : 3, characteristic of metallothioneins. In I, each of the four copper atoms is coordinated to three thiourea ligands and one iodide ion in a distorted tetrahedral mode adopting admantane-like structure. In II, four types of core arrangements are observed around copper(I), which include, Cu(μ-S₂)I₂, Cu(μ-S₂)(μ-I)I, Cu(μ-S₃)I, and Cu(μ-S₃)S each having copper(I) tetrahedrally coordinated. The complexes were also characterized by IR and ¹H and ¹³C NMR spectroscopy.     

几个金属卤素簇的合成与性能研究

The hydrothermal reaction of CuBr2 and CuBr with phen·H2O （phen= 1,10-phenanthroline） in a molar ratio of 1：1：1.5 gave birth to the first copper-halo cationic cluster [Cu2^Ⅱ Cu2^Br4 （phen）4 ] ^2＋（1） with tetranuclear anionic cluster [Cu4Br6]^2-. Changing the precursors or their molar ratios, two mononuclear complexes [Cu（phen）2Br]Br·H2O （2） and [Ni（phen）3][CuCl2]2 （3） as well as two unusual copper-halo chains found in polymers [Cu2Br2（phen）]∞ （4） and [Cu^ⅡCu3^ⅠBr2Ⅰ3 （phen）2 ]∞ （5） were obtained. The （Cu2Br2）∞ chain of 4 looks like a linearar ray of hexagons based on fused Cu3Br3 units, and the linear （Cu3Ⅰ3Br^-）∞ chain of 5 is an alternate combination of the rhombic Cu2I2 cores and the Cu4I4Br2^2- units. In addition, the hydrothermal reaction of CuBr2 with NA（NA=nicotinic acid） or INA （INA =isonicotinic acid） resulted in the syntheses of two compounds [CuBr（NA）] （6） and [CuBr（INA）]∞（7） containing staircase chain. Among them the third-order non-linear optical properties of 2, 5, 6 and 7 were investigated and all exhibit the reverse saturable absorption （α2〉0） and self-defocusing performance （n2〈0）.     

Structural and Spectroscopic Studies of Halocuprate(I) and Haloargentate(I) Complexes [M2XnX′4−n]2−

The complexes [Cu₂Br₄]^2?, [Cu₂I₄]^2?, [Cu₂I₂Br₂]^2?, [Cu₂I₃Cl]^2?, [Ag₂Cl₄]^2? have been characterized as their isomorphous bis(triphenylphosphoranylidene)ammonium ([Ph₃PNPPh₃]⁺ = PNP⁺) salts by single crystal structural determinations. All anions show the centrosymmetric doubly halogen‐bridged forms [XM(μ‐X)₂MX]^2? with three‐coordinate metal atoms that have been observed in [M₂X₄]^2? complexes with other large organic cations. In [Cu₂I₂Br₂]^2? the iodide ligands occupy the bridging positions and the bromide the terminal positions, while in [Cu₂I₃Cl]^2?, obtained in an attempt to prepare [Cu₂I₂Cl₂]^2?, two of the iodide ligands occupy the bridging positions with the third iodide and the chloride ligand occupying two statistically disordered terminal positions. In [Ag₂Cl₄]^2? the distortion from ideal trigonal coordination of the metal atom is greater than in the copper complexes, but less than in other previously reported [Ag₂Cl₄]^2? complexes with organic cations. The ν(MX) bands have been assigned in the far‐IR spectra, and confirm previous observations regarding the unexpectedly simple IR spectra of [Cu₂X₄]^2? complexes.     

Copper(I) complexes with fluorinated hydrotris(pyrazolyl)borate: Influence of electronic effects on their structure,physicochemical properties,and reactivity

Copper(I) coordination complexes of the anionic fluorinated ligand, hydrotris(3-trifluoromethyl-5-methyl-1-pyrazolyl)borate (L0f⁻), i.e. the copper(I) carbonyl complex, [Cu^I(L0f)(CO)] (1), the copper(I) triphenylphosphine complex, [Cu^I(L0f)(PPh₃)] (2), the copper(I) acetonitrile complex, [Cu^I(L0f)(NCMe)] (3), and the corresponding copper(I) triphenylphosphine complex with hydrotris(3,5-diisopropyl-1-pyrazolyl)-borate anion (L1⁻), i.e. [Cu^I(L1)(PPh₃)] (4), were synthesized in order to investigate the influence of the electron-withdrawing groups on the pyrazolyl rings. The structures of complexes 1, 2, and 4 were determined by X-ray crystallography. While X-ray crystallography did not show definitive trends in terms of copper(I) atom geometry, the clear influence of the electronic structure of the pyrazolyl rings is observed by spectroscopic techniques, namely, IR and multinuclear NMR spectroscopy. Finally, the relative stability of the copper(I) complexes is discussed.     

Hydrothermal Synthesis and Structures of Two New Molybdenum Phosphate Compounds based on Keggin Cluster Units

Two new molybdenum phosphate complexes, [Cu₂(phen)₄(μ‐Cl)][PMo₁₂O₄₀]·H₂O (phen = 1,10‐phenanthroline) ( 1 ) and (Hbpy)[Cu^I(bpy)]₂[PMo^V₂Mo^VI₁₀O₃₉] (bpy = 4,4′‐bipyridine) ( 2 ), have been prepared under mild hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction. Compounds 1 and 2 crystallize in triclinic system, space group , with a = 12.5458(7) Å, b = 13.4486(8) Å, c = 21.2406(12) Å, α = 99.7020(10)°, β = 94.2320(10)°, γ = 95.0890(10)°, V = 3504.2(3) ų and Z = 2 for 1 , and a = 10.7871(6) Å, b = 10.9016(6) Å, c = 12.7897(7) Å, α = 96.8500(10)°, β = 110.0850(10)°, γ = 103.5800(10)°, V = 1339.74(13) ų and Z = 1 for 2 . Compound 1 contains a [Cu₂(phen)₄(μ‐Cl)]³⁺ cation in which two similar [Cu(phen)₂] units are bridged by one chlorine atom. Compound 2 contains one‐dimensional straight chain of Keggin polyoxoanions [PMo^V₂Mo^VI₁₀O₃₉]_n^3? and two linear cationic chains of [Cu^I(bpy)]_nⁿ⁺. The molecular packing shows a two‐dimensional network, which is formed by the cross of the linear Keggin anions and Cu‐bpy cations.     

Copper(II) complex intercalated graphene oxide nanocomposites as versatile,reusable catalysts for click reaction

In this work, we report the efficient, high stable copper(II) complexes intercalated graphene oxide (GO) used as green catalysts for copper(II) complex mediated click reaction. Copper(II) Bis(2,2′-bipyridine) [Cu^II (bpy)₂] (C1) and Copper(II) Bis(1,10-phenanthroline) [Cu^II (phen)₂] (C2) have synthesized for the intercalation of corresponding nanocomposites with GO, [GO@Cu^II (bpy)₂] (GO-C1) and [GO@Cu^II (phen)₂] (GO-C2). The noncovalent interaction of complexes supported on the surface of the GO nanosheets proves as an evident active site to facilitate the enhanced catalytic activity of copper-catalyzed alkyne azide cycloaddition (Cu^IIAAC) reaction for the isolation of 1,4-disubstituted-1,2,3-triazoles as click products in shorter reaction time with 80%–91% yield (five examples). The X-ray diffraction (XRD) pattern of these composites shows the enhanced interlayers d-spacing range of 1.01–1.12 nm due to the intercalation of copper(II) complexes in between the GO basal planes and characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), Raman, UV, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The as-prepared nanocomposites were employed for the typical click reactions using the substrates of azide and acetylene. These classes of composite materials can be referred to recyclable, heterogeneous, green catalysts with high atom economy and could also be used for the isolation of click products in biomolecules.     

Copper Complexes with New Pyridylpyrazole Based Ligands

We report the synthesis, characterization, and crystal structures of new ligands of the pyridinylpyrazole type, i.e., 3,5‐bis(4‐butoxyphenyl)‐1‐(pyridin‐2‐yl)‐1H‐pyrazole ( L ¹ ) and 3,5‐bis(4‐phenoxyphenyl)‐1‐(pyridin‐2‐yl)‐1H‐pyrazole ( L ² ) (Scheme 1), and the study of their coordination behavior towards Cu^I and Cu^II. The versatility of this type of ligand, which can give access to different coordination spheres about the metal center, depending on the nature of the copper starting material used in the preparation of the complexes (Scheme 2), is illustrated. Thus, pseudo‐tetrahedral Cu^I as well as six‐coordinated tetragonal and distorted tetragonal pyramidal Cu^II derivatives were obtained for [Cu(L)₂]PF₆, [Cu(Cl)₂(L)₂] (L= L ¹ , L ² ), and [Cu(Cl)( L ¹ )₂]PF₆, respectively. We also present a crystallographic support of a distorted octahedral cis‐bis(tetrafluoroborato‐κF)copper(II) compound found for [Cu(BF₄)₂( L ¹ )₂] ( 3 ).     

Improved Photostability of a CuI Complex by Macrocyclization of the Phenanthroline Ligands

The development of molecular materials for conversion of solar energy into electricity and fuels is one of the most active research areas, in which the light absorber plays a key role. While copper(I)-bis(diimine) complexes [Cu^I(L)₂]⁺ are considered as potent substitutes for [Ru^II(bpy)₃]²⁺, they exhibit limited structural integrity as ligand loss by substitution can occur. In this article, we present a new concept to stabilize copper bis(phenanthroline) complexes by macrocyclization of the ligands which are preorganized around the Cu^I ion. Using oxidative Hay acetylene homocoupling conditions, several Cu^I complexes with varying bridge length were prepared and analyzed. Absorption and emission properties are assessed; rewardingly, the envisioned approach was successful since the flexible 1,4-butadiyl-bridged complex does show enhanced MLCT absorption and emission, as well as improved photostability upon irradiation with a blue LED compared to a reference complex.     

Copper(I) bromide and chloride complexes with urotropine and triethylenediamine: synthesis,crystal structure,and Raman characterization*

Abstract

In the present study, the oxidative dissolution of metallic copper has been explored with the intention to prepare some new complexes with urotropine (hmta) and triethylenediamine (dabco) ligands. All the compounds synthesized were characterized by single-crystal X-ray diffraction and Raman spectroscopy. Reactions performed in a DMSO/CuCl₂?2H₂O mixture resulted in [(μ-Cl)₂Cu^I(hdabco⁺)Cu^I(μ-Cl)(κS-DMSO)]_n and [Cu^ICl(hmta)₂] complexes. Their isostructural bromide analogs [(μ-Br)₂Cu^I(hdabco⁺)Cu^I(μ-Br)(κS-DMSO)]_n and [Cu^IBr(hmta)₂] were prepared by the reaction of elemental copper with respective ligands in a DMSO/CBr₄ mixture. Early interrupted reaction of the copper wire with the DMSO/CBr₄/dabco solution resulted in an appearance of crystals of the [Cu^I₂Br₂(CO)₂(dabco)]_n carbonyl complex on the copper surface. It arises with the participation of in situ formed carbon monoxide. Despite the identical stoichiometry, the crystal structure of the [Cu₂Br₂(CO)₂(dabco)]_n complex is markedly different from that of a known [Cu₂Cl₂(CO)₂(dabco)]_n analog.     

二个钴5-磺酸基水杨酸、邻菲罗啉配合物的合成、次级合成与结构

Cobait（Ⅱ） nitrate reacted with 1,10-phenanthroline （phen） and 5-sulfosaiicylic acid （H3ssal） to yield the cobait（Ⅰ） complex [Co（phen）2（H2O）2]（Hssal）o4H2O （1） and the reaction of 1 with copper acetate led to a novel complex [Co（phen）（H2O）4][Cu2（ssal）2（phen）2]·5H2O （2）. These two complexes were cationanion species and the cationic motif [Co（phen）2（H2O）2]^2＋of 1 could be converted to [Co（phen）（H2O）4]^2＋ in the formation process of new anion [Cu2（phen）2（ssal）2]^2- of 2. In both complexes abundant hydrogen bonds construct different supramolecular architectures, thus the conversion reaction can provide a new path to create novel supramolecular network.     

Facially Dispersed Polyhydride Cu9 and Cu16 Clusters Comprising Apex‐Truncated Supertetrahedral and Square‐Face‐Capped Cuboctahedral Copper Frameworks

By using a linear tetraphosphine, meso‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), nona‐ and hexadecanuclear copper hydride clusters, [Cu₉H₇(μ‐dpmppm)₃]X₂ (X=Cl ( 1 a ), Br ( 1 b ), I ( 1 c ), PF₆ ( 1 d )) and [Cu₁₆H₁₄(μ‐dpmppm)₄]X₂ (X₂=I₂ ( 2 c ), (4/3) PF₆?(2/3) OH ( 2 d )) were synthesized and characterized. They form copper‐hydride cages of apex‐truncated supertetrahedral {Cu₉H₇}²⁺ and square‐face‐capped cuboctahedral {Cu₁₆H₁₄}²⁺ structures. The hydride positions were estimated by DFT calculations to be facially dispersed around the copper frameworks. A kinetically controlled synthesis gave an unsymmetrical Cu₈H₆ cluster, [Cu₈H₆(μ‐dpmppm)₃]²⁺ ( 3 ), which readily reacted with CO₂ to afford linear Cu₄ complexes with formate bridges, leading to an unprecedented hydrogenation of CO₂ into formate catalyzed by {Cu₄(μ‐dpmppm)₂} platform. The results demonstrate that new motifs of copper hydride clusters could be established by the tetraphosphine ligands, and the structures influence their reactivity.     

Dinuclear Complexes of Copper(I) with Crown Ether‐containing N‐Thiophosphorylated Bis‐thioureas and 2,2′‐Bipyridine or 1,10‐Phenanthroline: Synthesis,Characterization, and Picrate Extraction Properties

Reaction of O,O′‐diisopropylthiophosphoric acid isothiocyanate (iPrO)₂P(S)NCS with 1,10‐diaza‐18‐crown‐6, 1,7‐diaza‐18‐crown‐6, or 1,7‐diaza‐15‐crown‐5 leads to the N‐thiophosphorylated bis‐thioureas N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6 ( H₂L^I ), N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,7‐diaza‐18‐crown‐6 ( H₂L^II ) and N,N′‐bis[C(S)NHP(S)(OiPr)₂]‐1,7‐diaza‐15‐crown‐5 ( H₂L^III ). Reaction of the potassium salts of H₂L^I–III with a mixture of CuI and 2,2′‐bipyridine ( bpy ) or 1,10‐phenanthroline ( phen ) in aqueous EtOH/CH₂Cl₂ leads to the dinuclear complexes [Cu₂(bpy)₂L^I–III] and [Cu₂(phen)₂L^I–III] . The structures of these compounds were investigated by ¹H, ³¹P{¹H} NMR spectroscopy, and elemental analysis. The crystal structures of H₂L^I and [Cu₂(phen)₂L^I] were determined by single‐crystal X‐ray diffraction. Extraction capacities of the obtained compounds in comparison to the related compounds 1,10‐diaza‐18‐crown‐6, N,N′‐bis[C(=CMe₂)CH₂P(O)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6, N,N′‐bis[C(S)NHP(O)(OiPr)₂]‐1,10‐diaza‐18‐crown‐6 towards the picrate salts LiPic, NaPic, KPic. and NH₄Pic were also studied.     

Chemical characteristics of the products of the complexation reaction between copper(II) and a tetra-aza macrocycle in the presence of chloride ions

The reaction of copper(II) perchlorate with the hydrochloride salt of 3,6,9,15-tetra-azabicyclo[9.3.1]penta-deca-1,11,13-triene (L1) in acetonitrile forms two macrocyclic complexes that can be characterized: [L1Cu^IICl][ClO₄] (1) and [L1Cu^IICl]₂[CuCl₄] (2). The structural, electronic, and redox properties of these complexes were studied using spectroscopy (EPR and UV–visible) and electrochemistry. In addition, the solid-state structure of 1 was obtained using X-ray diffraction. The copper(II) is five-coordinate ligated by four N-atoms of the macrocycle and a chloride atom. EPR studies of 1 both in DMF and aqueous solution indicate the presence of a single copper(II) species. In contrast, EPR studies of 2 performed in frozen DMF and in the solid-state reveal the presence of two spectroscopically distinct copper(II) complexes assigned as [L1Cu^IICl]⁺ and [Cu^IICl₄]^2?. Lastly, electrochemical studies demonstrate that both [L1Cu^IICl]⁺ and [Cu^IICl₄]^2? are redox active. Specifically, the [L1Cu^IICl]⁺ undergoes a quasi-reversible Cu(II)/(I) redox reaction in the absence of excess chloride. In the presence of chloride, however, the chemical irreversibility of this couple becomes evident at concentrations of chloride that exceed 50 mM. As a result, the presence of chloride from the chemical equilibrium of this latter species impedes the reversibility of the reduction of [L1Cu^IICl]⁺ to [L1Cu^ICl]⁰.     

Metalloantitubercular compounds Part 3: Synthesis,crystal structure,spectroscopy, electrochemistry and antimycobacterial activity of the copper(II) ciproploxacin (cfH) complex and its phenanthroline adduct

The X-ray crystal structures of two ciprofloxacin compounds, viz. [Cu(cfH)₂(Cl)₂] · ₂MeOH · 6H₂O (2) and [Cu(cfH)(phen)Cl]BF₄ · 4H₂O (3) are reported. Complex (2) has a distorted octahedral geometry, whereas for the nitrogen adduct (3) a distorted square–pyramidal geometry is seen. Significant enhancement in the antimycobacterial activity of the copper conjugates correlates with their copper redox couples (Cu²⁺ /Cu⁺) probably due to its relevance to intracellular accumulations and subsequent role in generating oxidative stress.     

Spectroscopic and electrochemical study of dinuclear and mononuclear copper complexes with the bidentate ligand of the 2,2′-diquinoline series

The newly synthesized complex (2) of copper(I) chloride with di-n-hexyl 2,2′-biquinoline-4,4′-dicarboxylate (L) was spectroscopically and electrochemically characterized. The X-ray diffraction study showed that the crystals of complex 2 consist of the dinuclear moieties [L₂Cu¹ ₂(μ-Cl)₂] containing Cu₂(μ-Cl)₂ clusters. Spectrophotometric studies and ESI-mass spec-trometric measurements showed that after the dissolution of complex 2 in acetonitrile (AN) and N-methyl-2-pyrrolidone (NMP), the solution contained not only the dinuclear complexes [L₂Cu¹ ₂(μ-Cl)₂] but also [L₂Cu¹]Cl, [LCu¹Cl(Sol)], and [Cu¹Cl(Sol)] (Sol is the solvent). The electrochemical data also confirm the conclusion that bridged dinuclear chloride complex 2 dissociates both in NMP and AN to form the tetrahedral bis-biquinoline complex [L₂Cu¹]Cl. In solutions of complex 2 in alcohols and _N,_N-dimethylformamide (DMF), only [L₂Cu¹]Cl and [Cu¹Cl(Sol)] are present. In EtOH, AN, and DMF, [Cu¹Cl(Sol)] undergoes disproportionation to [Cu¹¹Cl(Sol)] and Cu⁰.     

Syntheses and crystal structures of two heterometallic iodoplumbates containing mixed‐valence copper(I/II)

Mixed‐valence copper(I/II) atoms have been introduced successfully into a Pb/I skeleton to obtain two heterometallic iodoplumbates, namely poly[bis(tetra‐n‐butylammonium) [bis(μ₃‐dimethyldithiocarbamato)dodeca‐μ₃‐iodido‐hexa‐μ₂‐iodido‐tetracopper(I)copper(II)hexalead(II)]], {(C₁₆H₃₆N)₂[Cu₄^ICu^IIPb₆(C₃H₆NS₂)₂I₁₈]}_n , (I), and poly[[μ₃‐iodido‐tri‐μ₂‐iodido‐iodido[bis(1,10‐phenanthroline)copper(I)]copper(I)copper(II)lead(II)] hemiiodine], {[Cu^ICu^IIPbI₅(C₁₂H₈N₂)₂]·0.5I₂}_n , (II), under solution and solvothermal conditions, respectively. Compound (I) contains two‐dimensional anionic layers, which are built upon the linkages of Cu^II(S₂CNMe₂)₂ units and one‐dimensional anionic Pb/I/Cu^I chains. Tetra‐n‐butylammonium cations are located between the anionic layers and connected to them via C—H…I hydrogen‐bonding interactions. Compound (II) exhibits a one‐dimensional neutral structure, which is composed of [PbI₅] square pyramids, [Cu^II₄] tetrahedra and [Cu^IIN₄I] trigonal bipyramids. Face‐to‐face aromatic π–π stacking interactions between adjacent 1,10‐phenanthroline ligands stabilize the structure and assemble compound (II) into a three‐dimensional supramolecular structure. I₂ molecules lie in the voids of the structure.     

Synthesis and antimicrobial evaluation of coordination compounds containing 2,2′-bis(3-aminopyridyl) diselenide as ligand

The reaction between 2,2′-bis(3-aminopyridyl) diselenide (L) and metal transition salts results in the formation of molecular or cluster complexes. The structural elucidation of the synthesized complexes [CuCl₂(L)] ( 1 ), [Cu(3-NH₂PySeO₂)₂]·2H₂O ( 2 ), [Cu₄(3-NH₂PySe)₄]·dimethylformamide ( 3 ), [CoCl₂(L)] ( 4 ), [ZnCl₂(L)] ( 5 ), and [Ag₆(3-NH₂PySe)₆] ( 6 ) demonstrates the coordination of nitrogen atoms to Cu^II, Co^II, and Zn^II, and that of the selenium atoms to Cu^I and Ag^I, which agrees with Pearson’s hard and soft acids and bases (HSAB) theory. Furthermore, the oxidation of selenium with the formation of 3-aminopyridylseleninate [3-NH₂PySeO₂]⁻ bonded to the copper atom was observed in complex 2 . The antimicrobial action of complexes 1 , 2 , 4 , and 5 was evaluated against Mycobacterium fortuitum, Mycobacterium massiliense, and Mycobacterium abscessus. It was observed that all these complexes have potential antimicrobial activity compared with the free ligand and metal salts used in the synthesis.     

Structural characterization,DFT studied,luminescent properties of cationic/neutral three-coordinated copper (I) complexes and application in warm-white light-emitting diode

A series of cationic/neutral copper (I) complexes, [Cu₂(Hbmb)(PPh₃)₄] (BF₄)₂ ( 1a ), [Cu₂(Hbmb)(DPEPhos)₂](BF₄)₂ ( 2a ), [Cu₂(Hbmb)(Xantphos)₂](BF₄)₂ ( 3a ), [Cu₂(bmb)(PPh₃)₄] ( 1b ), [Cu₂(bmb)(DPEPhos)₂] ( 2b ), [Cu₂(bmb)(Xantphos)₂] ( 3b ) (Hbmb = 1,4-bis (1H-benzimidazol −2-yl)benzene, PPh₃ = triphenylphosphine, DPEPhos = bis[2-(diphenylphosphino)-phenyl]ether, Xantphos =4,5-bis (diphenylphosphino)-9,9′-dimethyl-xanthene), have been synthesized and characterized by IR, TGA, XRD and X-ray crystal structure analysis. The structural analysis reveals that each Cu⁺ in all complexes adopts an almost ideal trigonal planar geometry, with three coordinate NP₂, and the C-H···π and π···π interactions are observed in the packing structures. DFT studied indicate the ingredients of the HOMOs and LUMOs for neutral copper (I) complexes 1b , 2b and 3b are different from cationic copper (I) complexes 1a , 2a and 3a , in accordance with the distribution of Mülliken atomic charges. Meanwhile, neutral copper (I) complexes 1b , 2b and 3b have fascinating broad blue-green emission bands at room temperature, while cationic copper (I) complexes 1a , 2a and 3a exhibit the existence of multiple emission peaks. Furthermore, the maximum phosphorescent lifetime and quantum yield at room temperature, for all copper (I) complexes, are 1143 μs and 8.82%, respectively. In addition, in order to measure the practical application of these complexes, the selection of complex 1b is used to fabricate the LED, which emits a bright warm-white light.