Hexanuclear Copper Research Articles

Synthesis, characterization and magnetic properties of a hexanuclear copper (II) complex with hydroxido, alkoxido and phenoxido bridges

A new CuII6 complex, formulated as [Cu6(L)3(µ3-OH)(H2O)(OH)(NO3)]·2H2O·7CH3OH (1) has been prepared using the symmetrical N2O3-donor Schiff-base ligand H3L = N,N′-(2-hydroxypropane-1,3-diyl)bis(2-hydroxyacetophenimine). Compound 1 has been structurally and spectroscopically characterized. Single crystal X-ray diffraction analysis reveals that 1 crystallizes in the triclinic space group P-1 and consists of a CuII6 complex where each deprotonated ligand chelates two CuII centres. Three of the six independent CuII centres are arranged in an almost equilateral triangle with double Cu-O-Cu bridges, formed by a μ3-hydroxido and phenoxido bridges. Each of the three CuII centres in the triangle is further connected to one CuII centre through a single alkoxido bridge. The magnetic properties indicate the presence of moderate and weak antiferromagnetic interactions through the double and single oxido bridges, respectively.

Heterometallic Cu−Ca/Ba MOFs of 2‐Mercaptonicotinic Acid for Fast Sensing of Fe3+, Cr2O72−/CrO42− in Water

AbstractTwo heterometallic Cu−Ca/Ba metal organic frameworks (MOFs), {[Ca(H2O)6][Cu6Ca2(mna)6(H2O)6] ⋅ 6H2O}n (1) and {[(Cu6Ba3(mna)6(H2O)8] ⋅ 6H2O}n (2), were synthesized by using 2‐mercaptonicotinic acid (H2mna) as ligand via liquid‐liquid diffusion method. The frameworks of compounds 1 and 2 are both adopts hexanuclear copper cluster of [Cu6(mna)6]6− as building units. In 1, the two‐dimensional (2D) structure is formed by the linkage between [Cu6(mna)6]6− and monomeric Ca2+, while the three‐dimensional (3D) framework of 2 is constructed by [Cu6(mna)6]6− and trimer of Ba2+. Furthermore, compounds 1 and 2 show excellent photoluminescence with red emitting around 700 nm. Luminescent studies reveal that 1 can serve as a probe for the rapid detection of Fe3+, Cr2O72− and CrO42− ions in water with remarkable selectivity even in the presence of other analogous ions.

Boron cluster anions [BnHn]2– (n = 10, 12) in design of polynuclear silver(I) and copper(II) complexes

The role of boron cluster anions [BnHn]2– (n = 10, 12) in the stabilization of polynuclear compounds was shown. Tetranuclear silver(I) complex [Ag4(bipy)4[B12H12]2] (1) (bipy is 2,2ʹ-bipiridyl) and hexanuclear copper(II) complex [[CuII2(bipy)4(μ–CO3)]2[(CuII2(bipy)2(μ–OH)2]][Ag[B10H10]2]2∙5DMF (2∙5DMF) stabilized by first complex trianion [Ag[B10H10]2]3– were isolated and their structures were determined by single crystal X-ray diffraction. Based on the data of physicochemical methods of analysis (IR, Raman spectroscopy, as well as X-ray diffraction data for the polymer complex {[Ag(CH3CN)3][Ag[B10H10]]}n (3) possible mechanisms for the formation of polynuclear complexes were proposed.

Hexabranched dendrimers encapsulated metallic copper nanoparticles and their catalytic evaluation for the conversion of para-nitrophenol to para-aminophenol

Two new hexanuclear copper (II) complexes, [Cu6(G2hexpyD)(DMF)24](TFA)12 and [Cu6(G2hexbzaD)(DMF)18](TFA)12, where G2hexpyD and G2hexbzaD are second-generation dendrimers (G = 2) and TFA is trifluoroacetate, have been synthesized. The prepared copper (II) complexes have been fully characterized. Furthermore, to prepare dendrimer encapsulated copper nanoparticles (G2dendrimer-CuNPs), metal ions were chemically reduced by NaBH4 in 2-methoxyethanol, which yielded zero-valent metal particles with a narrow size distribution. The catalytic reduction of para-nitrophenol to para-aminophenol by G2dendrimer-CuNPs was evaluated in the presence of NaBH4. The reduction reaction was completed in 3 min. The reaction progress was monitored by electronic absorption spectroscopy. The rate constant was calculated to be 0.0073 and 0.0079 s−1 for G2hexbzaD-CuNPs and G2hexpyD-CuNPs, respectively. The results revealed that G2dendrimer-CuNPs exhibit high catalytic performance in the conversion of para-nitrophenol to para-aminophenol. Easy separation, low price, high recyclability and great efficiency are the main advantages of G2dendrimer-CuNPs that make them as the suitable catalysts for the catalytic reduction of para-nitrophenol.

Selective Generation of Electroreduction C 1 –C 2 Products Through Self-Regulation of Catalytically Active Cu Sites on the Same Coordination Cluster Catalyst

Open AccessCCS ChemistryRESEARCH ARTICLES14 Dec 2022Selective Generation of Electroreduction C1-C2 Products through Self-Regulation of Catalytically Active Cu Sites on The Same Coordination Cluster Catalyst Rui Wang, Jiang Liu, Long-Zhang Dong, Jie Zhou, Qing Huang, Yi-Rong Wang, Jing-Wen Shi and Ya-Qian Lan Rui Wang Google Scholar More articles by this author , Jiang Liu Google Scholar More articles by this author , Long-Zhang Dong Google Scholar More articles by this author , Jie Zhou Google Scholar More articles by this author , Qing Huang Google Scholar More articles by this author , Yi-Rong Wang Google Scholar More articles by this author , Jing-Wen Shi Google Scholar More articles by this author and Ya-Qian Lan Google Scholar More articles by this author https://doi.org/10.31635/ccschem.022.202202316 SectionsSupplemental MaterialAboutPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Well-defined crystalline coordination compound catalysts have showcased distinct advantages in the regulation of the species and selectivity of electrocatalytic CO2 reduction products. However, the systematic study of the crystal-facet effect of crystalline coordination compound on the performance of electrocatalytic CO2 reduction has not yet been reported. Herein, a stable hexanuclear copper cluster (Cu6) catalyst model system is designed and synthesized. By effectively regulating the growth size (micro-nano size) and morphology of Cu6 single crystal, Cu6(P) with the main (100) facet, Cu6(H) with the main (100) and (001) facet, and Cu6(S) with the main (001) facet are obtained. From Cu6(P)via Cu6(H) to Cu6(S), there is a shift from the predominantly exposed the (100) facet (involving two nonadjacent active Cu sites) to (001) facet ((involving three adjacent active Cu sites), which directly affects the adsorption direction of the key *CO intermediate and the potential of C-C coupling, thus enabling effective regulation of the selectivity of C1 (CO and CH4) and C2 (C2H4) reduction products. This work provides an essential molecular model system and a novel design perspective for the systematic study of the crystal-facet effect of coordination compounds on the species and selectivity of CO2RR products. Download figure Download PowerPoint Previous articleNext article FiguresReferencesRelatedDetails Issue AssignmentNot Yet AssignedSupporting Information Copyright & Permissions© 2022 Chinese Chemical Society Downloaded 77 times PDF downloadLoading ...

Solid-State Self-Assembly of a Linear Hexanuclear Copper(II) Oxamate Complex with Alternating Antiferro- and Ferromagnetic Coupling

In this work, we describe the synthesis, crystal structure and magnetic properties of the neutral hexacopper(II) complex of formula {[Cubpca)]2[Cu(dmopba)(H2O)]}2·4H2O (1), where Hbpca = bis(2-pyridylcarbonyl)-amide and dmopba = 4,5-dimethyl-1,2-phenylenebis(oxamato). Single crystals of 1 were obtained from the stoichiometric reaction (1:2 molar ratio) of the mononuclear copper(II) complexes (n-Bu4N)2[Cu(dmpba)] and [Cu(bpca)(H2O)2]NO3·2H2O through slow diffusion techniques in water as a solvent. The crystal structure of 1 shows that two neutral {[Cu(bpca)]2[Cu(dmopba)(H2O)]} trinuclear units are connected through double out-of-plane copper to outer carboxylate oxygen atoms resulting in a unique oxamate-bridged linear hexanuclear complex. Hydrogen bonds among adjacent entities involving the non-coordinated water molecules result in a supramolecular 3D network. Magnetic measurements on 1 show the occurrence of moderate antiferromagnetic intratrinuclear interactions between the copper(II) ions from the [Cu(bpca)]+ and [Cu(dmopba)(H2O)]2− fragments across the oxamate bridge and a weak intertrinuclear ferromagnetic interaction between the copper(II) ions that occurs between the two central [Cu(bpca)]+ fragments mediated by the carboxylate groups from the oxamate bridge [J = −31.96(2) cm−1 and J′ = +1.34(2) cm−1; H = J (S1·S2 + S2·S3 + S1′·S2′ + S2′·S3′) + J′ (S1·S1′)].

Barrel-Shaped-Polyoxometalates Exhibiting Electrocatalytic Water Reduction at Neutral pH: A Synergy Effect.

Two copper-based barrel-shaped polyoxometalates (POMs), namely, [{H3O}4{Na6(H2O)22}][{CuI (H2O)3}2{CuII (H2O)}3{B-α-BiIIIWVI9O33}2]·7H2O (NaCu-POM) and Li4[{NH4}2{H3O}3{Li(H2O)5}][{CuII(SH)}{(CuIICuI1.5)(B-α-BiIIIWVI9O33)}2]·9H2O (LiCu-POM) have been synthesized and structurally characterized. The single-crystal X-ray diffraction analyses of NaCu-POM and LiCu-POM reveal the presence of penta- and hexa-nuclear copper wheels per formula units, respectively; these copper wheels are sandwiched between two lacunary Keggin anions {B-α-BiIIIWVI9O33}9- (BiW9) to form the barrel-shaped title POM compounds. In both the compounds NaCu-POM and LiCu-POM, the mixed-valent copper centers are present in their respective penta- and hexa-nuclear copper wheels, established by X-ray photoelectron spectroscopy (XPS) as well as by bond valence sum (BVS) calculations. Compound LiCu-POM additionally shows the presence of a sulfhydryl ligand (SH-), coordinated to one of the copper centers of its {Cu6}-wheel, that is expected to be generated from the in situ reduction of sulfate anion present in the concerned reaction mixture (lithium-ion in ammonia solution may be the reducing agent). Interestingly, the title compounds, NaCu-POM and LiCu-POM exhibit an efficient electrocatalytic hydrogen evolution reaction (HER) by reducing water at neutral pH. Detailed electrochemical studies including controlled experiments indicate that the active sites for this electrocatalysis are the W(VI) centers of the title compounds, not the copper centers. However, a relevant tri-lacunary Keggin cluster anion {PVWVI9O33}7- (devoid of copper ion) does not show comparable HER as shown by the title compounds. The intra-cluster cooperative interactions of the mixed-valent copper centers (CuII/CuI) with the tungsten centers (W6+) make the overall system electrocatalytically active toward water reduction to molecular hydrogen at neutral pH. High Faradaic efficiencies (89 and 92%) and turnover frequencies (1.598 s-1 and 1.117 s-1) make the title compounds NaCu-POM and LiCu-POM efficient catalysts toward electrochemical water reduction to molecular hydrogen.

A hexa-Cu cluster sandwiched silicotungstate with reactive oxygen species catalytic ability and anti-tumor activity in PC12 cells

A sandwich-type polyoxometalate (POM) based on a hexa-nuclear copper cluster and trivacant B-α-Keggin-type silicotungstate [Cu(en)2][Cu(en)2H2O]2{[Cu(en)2][Cu6(en)2(H2O)2(SiW9O 34)2]}·8H2O (SCW) (ethylenediamine = en) has been synthesized and structurally featured by X-ray photoelectron spectrum (XPS), IR and UV spectra, and single-crystal X-ray diffraction (SXRD). According to the structural analysis, the principal element of the SCW is a 1-D linear polyoxoanion that is alternately joined by {[Cu6(en)2(H2O)2(SiW9O34)2]}8– fragments and [Cu(en)2]2+ complexes. The cations of SCW are present in two forms: [Cu(en)2H2O]2+ and [Cu(en)2]2+. Notably, the Cu ions have been shown to coexist in the SCW with quad-coordination, penta-coordination, and hexa-coordination, which is rare in polyoxometalates. It is also demonstrated that SCW can efficiently catalyze the production of reactive oxygen species (ROS) by the synergistic action between copper complexes and POM fragments. Furthermore, SCW exhibits ability in anti ROS-sensitive tumor cells, such as PC12 cells.

High-pressure X-ray Power Diffraction Analysis of Photoluminescent Hexanuclear Copper(I) Complex

High-pressure X-ray Power Diffraction Analysis of Photoluminescent Hexanuclear Copper(I) Complex

Hexanuclear copper(II) complex of 2-hy-droxy-N,N'-bis-[1-(2-hy-droxy-phen-yl)ethyl-idene]propane-1,3-di-amine incorporating an open-cubane core.

The title mol-ecular structure, namely, di-aqua-tris-(μ3-1,3-bis-{[1-(2-oxidophen-yl)ethyl-idene]amino}-propan-2-olato)-μ3-hydroxido-dinitrato-hexa-copper(II) ethanol tris-olvate, [Cu6(C19H19N2O3)3(NO3)2(OH)(H2O)2]·3C2H5OH, corres-ponds to a non-symmetric hexa-nuclear copper complex. The complex exhibits one core in which three CuII metal centres are mutually inter-connected, two by two, via three phenolato oxygen anions acting in a μ2-mode. These three copper cations are inter-connected in a μ3-mode by one hydroxyl group. An open-cube structure is generated in which each of the CuII cations of the three CuO4N units is connected by two μ2-O anions from phenolate groups and one μ3-O atom from a hy-droxy anion. Each of the three penta-coordinated CuII cations situated in the open-cube unit has a distorted NO4 square-pyramidal environment. Each of these three CuII centres is inter-connected with another CuII cation via one enolate O atom in μ2-mode, yielding one CuNO4 unit and two CuNO3 units. The penta-coordinated CuII atom has a distorted square-pyramidal environment while the two tetra-coordinated copper(II) cations are situated in a square-planar environment. A series of intra-molecular O-H⋯O hydrogen bonds are observed. In the crystal, the units are connected two by two by inter-molecular C-H⋯O and O-H⋯O hydrogen bonds, thus forming sheets parallel to the ac plane.

Thermodynamic and solubilization properties of a polynuclear copper complex in ionic surfactants media

The solubilization behavior of hexanuclear copper complex, [Cu6(η1 :μ2 -C4H10NO)4(η1 :η1 :μ2 -C5H9O2)4(η1 :μ1 -C5H9O2)2(μ 3-OH)2] (1) (where, C4H10NO = N,N-dimethylethanolamine and C5H9O2 = pivalic acid) ionic micellar media has been explored in this study. The interaction of copper cluster under investigation (1) was experimented with an anionic surfactant (sodium lauryl sulfate; SLS) and a cationic surfactant (cetyltrimethyl ammonium bromide; CTAB). Solubilization was observed in aqueous solutions of ionic surfactants at their pre-micellar, micellar and post-micellar concentrations ranges using UV–Visible spectroscopy and electrical conductivity. The thermodynamic attributes of micellization including standard entropy (ΔSmic ), enthalpy (ΔHmic ) and free energy (ΔGmic ) were estimated from electrical conductivity measurements. The negative values of ΔGmic and ΔHmic indicated the stability of micellization, in addition to the enthalpy and entropy-driven nature of the process. Thermodynamic studies demonstrate increases in the CMC of both surfactants due to incorporation of the copper complex in the micelles. Partitioning and binding parameters were revealed by UV–Vis spectroscopy to quantitatively measure the interaction of the copper cluster with the surfactant in terms of partition constant (Kc ), partition coefficient (Kx ), binding coefficient (Kbind ), and free energies of free energy of partition (ΔGpart ) and binding (ΔGbind ). The presence of cationic CTAB led to greater red-shift in UV–Vis study of 1 as compared to SLS due to stronger ionic interactions. The strong interaction and high solubility have been seen in 1 with CTAB as compared to SLS.

Ferro- and Antiferromagnetic Interactions in Oxalato-Centered Inverse Hexanuclear and Chain Copper(II) Complexes with Pyrazole Derivatives.

Two novel copper(II) complexes of formulas {[Cu(4-Hmpz)4][Cu(4-Hmpz)2(µ3-ox-κ2O1,O2:κO2′:κO1′)(ClO4)2]}n (1) and {[Cu(3,4,5-Htmpz)4]2[Cu(3,4,5-Htmpz)2(µ3-ox-κ2O1,O2:κO2′:κO1′)(H2O)(ClO4)]2[Cu2(3,4,5-Htmpz)4(µ-ox-κ2O1,O2:κ2O2′,O1′)]}(ClO4)4·6H2O (2) have been obtained by using 4-methyl-1H-pyrazole (4-Hmpz) and 3,4,5-trimethyl-1H-pyrazole (3,4,5-Htmpz) as terminal ligands and oxalate (ox) as the polyatomic inverse coordination center. The crystal structure of 1 consists of perchlorate counteranions and cationic copper(II) chains with alternating bis(pyrazole)(µ3-κ2O1,O2:κO2′:κO1′-oxalato)copper(II) and tetrakis(pyrazole)copper(II) fragments. The crystal structure of 2 is made up of perchlorate counteranions and cationic centrosymmetric hexanuclear complexes where an inner tetrakis(pyrazole)(µ-κ2O1,O2:κ2O2′,O1′-oxalato)dicopper(II) entity and two outer mononuclear tetrakis(pyrazole)copper(II) units are linked through two mononuclear aquabis(pyrazole)(µ3-κ2O1,O2:κO2′:κO1′-oxalato)copper(II) units. The magnetic properties of 1 and 2 were investigated in the temperature range 2.0–300 K. Very weak intrachain antiferromagnetic interactions between the copper(II) ions through the µ3-ox-κ2O1,O2:κO2′:κO1′ center occur in 1 [J = −0.42(1) cm−1, the spin Hamiltonian being defined as H = −J∑S1,i · S2,i+1], whereas very weak intramolecular ferromagnetic [J = +0.28(2) cm−1] and strong antiferromagnetic [J’ = −348(2) cm−1] couplings coexist in 2 which are mediated by the µ3-ox-κ2O1,O2:κO2′:κO1′ and µ-ox-κ2O1,O2:κ2O2′,O1′ centers, respectively. The variation in the nature and magnitude of the magnetic coupling for this pair of oxalato-centered inverse copper(II) complexes is discussed in the light of their different structural features, and a comparison with related oxalato-centered inverse copper(II)-pyrazole systems from the literature is carried out.

Regulating the near-infrared region to visible-light emission by adjusting cuprophilic interactions for blue light-excited phosphors

Reported here for the first time the luminescence regulation of hexanuclear copper(i) nanoclusters by regulating cuprophilic interactions for blue light-excited phosphors.

Hexanuclear Copper(I) Hydride from the Reduction-Induced Decarboxylation of a Dicopper(II) Formate.

Copper(I) hydride complexes represent a promising entry into formic acid dehydrogenation catalysis. Herein we present the spontaneous decarboxylation of a μ1,3-formate-bridged dicopper(II) complex (1H) to a hexacopper(I) hydride cluster (2H) upon reduction. Isotopic labeling studies revealed that both the H- and CO2 originate from the bound μ1,3-formate in 1H, which represents a key step of the metal-mediated formic acid dehydrogenation. The full reaction equation for the conversion of 1H to 2H is established. The structure of 2H features two Cu3 triangles, each capped by a hydride ligand. Typical hydride reactivity of 2H is demonstrated by the addition of phenylacetylene, leading to the replacement of the hydrides by alkynide ligands -C≡CPh (3) while retaining the hexacopper(I) core. Temperature-dependent dynamic behavior in solution on the NMR time scale was observed for both 2H and 3, reflecting the rich structural landscape of the bis(pyrazolate)-bridged hexacopper(I) core (four isomers each for 2H and 3) predicted by DFT calculations.

Tetra- and hexanuclear copper(I) iminothiolate complexes: synthesis, structures, and solid-state thermochromic dual emission in visible and near-infrared regions

Two new photoluminescent multinuclear Cu(I) cluster complexes supported by monoanionic bidentate ligand N-methylbenzimidazolethiolate (Me-bimt–), [Cun(Me-bimt)n] with n = 4 (1) and 6 (2), have been synthesized and structurally characterized by single-crystal X-ray diffraction analysis. For 1 and 2, the Cu(I) ions and the Me-bimt– ligands construct a cubane-type {Cu4S4} and a hexagonal-prism {Cu6S6} frameworks, respectively. In the crystalline state, complexes 1 and 2 exhibit green (λem = 500 nm) and near-infrared (λem = 876 nm) emission, respectively, under UV irradiation (λex = 365 nm) at room temperature. Both crystals reveal temperature-dependent dual emission below 200 K: complex 1 emits in the visible wavelength region (λem = 493 and 542 nm) and complex 2 in the visible to near-infrared wavelength region (λem = 752 and 973 nm) which are attributed to multiple photoexcited states at the cluster frameworks with distinct metal nuclearity.

Bis(μ2-benzoato-κ2 O,O′)bis(benzoato-κO)bis(ethanol-κO)bis(μ3-hydroxido)hexakis(μ-pyrazolato-κ2 N,N′)hexacopper(II) ethanol disolvate

Trinuclear copper–pyrazolate entities are present in various Cu-based enzymes and nanojar supramolecular arrangements. The reaction of copper(II) chloride with pyrazole (pzH) and sodium benzoate (benzNa) assisted by microwave radiation afforded a neutral centrosymmetric hexanuclear copper(II) complex, [Cu6(C7H5O2)4(OH)2(C3H3N2)6(C2H5OH)2]·2C2H5OH. Half a molecule is present in the asymmetric unit that comprises a [Cu3(μ3-OH)(pz)3]2+ core with the copper(II) atoms arranged in an irregular triangle. The three copper(II) atoms are bridged by an O atom of the central hydroxyl group and by three bridging pyrazolate ligands on each of the sides. The carboxylate groups show a chelating mode to one and a bridging syn,syn mode to the other two CuII atoms. The coordination environment of one CuII atom is square-planar while it is distorted square-pyramidal for the other two. Two ethanol molecules are present in the asymmetric unit, one binding to one of the CuII atoms, one as a solvent molecule. In the crystal, stabilization arises from intermolecular O—H...O hydrogen-bonding interactions.

Synergistic Cu2 Catalysts for Formic Acid Dehydrogenation.

Hexanuclear copper hydride complexes, [Cu6(μ3-H)2( meso-L4)3(RNC)4](PF6)4 (R = tBu (6a), Cy (6b)), were prepared by using a new linear tetraphosphine, meso-Ph2PCH2P(Ph)(CH2)4P(Ph)CH2PPh2 ( meso-L4), and were converted into active catalysts of [Cu2(μ-O2CH)( meso-L4)(RNC)2]+ under the reaction conditions of formic acid dehydrogenation, where unsymmetric dinuclear copper sites supported by the tetradentate phosphine and isocyanide ligands were essential to demonstrate effective catalytic activity.

On the Nature of Luminescence Thermochromism of Multinuclear Copper(I) Benzoate Complexes in the Crystalline State

A model luminescent [(PhCO2)4Cu4] (Cu4) complex in the crystalline state was investigated via combined crystallographic and spectroscopic techniques contributed substantially by theoretical modelling. The complex appeared to exhibit luminescence thermochromism, i.e., red phosphorescence at room temperature which changes to green when lowering the temperature to 90 K. The low-energy emissive state was assigned as a cluster-centred triplet, 3CC. The emission from this state predicted in TDDFT (~635 nm) matches the experimental red band observed at 660–715 nm. In contrast, the nature of the high-energy “green” band was less straightforward. The next reached cluster-centred triplet excited state occurred to be energetically close to the experimental value of ~545 nm. The two excited states also exhibit significant metal-to-ligand and ligand-to-metal charge transfer characteristics, especially for solid-state distorted geometries. In both cases the cluster core was expected to become notably contracted when compared to the ground state. Time-resolved photocrystallographic results supported the computationally predicted core contraction upon excitation. Additionally, the differences between the spectroscopic behaviour of the related tetra- and hexanuclear copper(I) complexes, Cu4 and Cu6 (i.e., [(PhCO2)6Cu6]) in the crystalline state were discussed and examined. It appeared that crystal packing may constitute an important factor as far as the lack of luminescence thermochromism in the latter case is concerned. Synopsis: Structure–property relationships characterising a model luminescent [(PhCO2)4Cu4] (Cu4) complex in the crystalline state were investigated via combined crystallographic and spectroscopic techniques contributed by theoretical modelling, and compared with the properties of the related [(PhCO2)6Cu6] (Cu6) complex.

The Assembly of Unique Hexanuclear Copper(I) Complexes with Effective White Luminescence.

The unique L2Cu6I6 complexes containing two Cu3I3 units have been obtained via reaction of 1,5-diaza-3,7-diphosphacyclooctanes bearing ethylpyridyl substituents at phosphorus atoms with an excess of copper iodide. The structure of one of the complexes was confirmed by X-ray diffraction. It was shown that the complexes can exist in two crystalline phases with different parameters of the unit cell, which were detected by the PXRD data analyses. The solvent-free crystalline phases of the complexes display rare solid-state white emission at room temperature, which is observed due to the presence of two broad bands in the emission spectra with maxima at 464 and 610 nm. Quantum chemical computations show that the high-energy band has 3(M+X)LCT origin, whereas the low-energy band is interpreted as 3CC. The quantum yields of white luminescence of complexes reach 15-20%.

Chemical biology suggests pleiotropic effects for a novel hexanuclear copper(ii) complex inducing apoptosis in hepatocellular carcinoma cells.

A novel hexanuclear copper(ii)-based complex, [Cu6(tpbb)2(NO3)12] (1), was synthesized, which shows potent cytotoxicity to hepatoma carcinoma cells by inducing apoptosis and apoptosis-related processes. Furthermore, mechanistic investigations based on proteomes revealed that the induced apoptosis was mediated by acting on several targets and multiple pathways in a pleiotropic way.