Small Molecule Copper Research Articles

Small-Molecule Copper Chloride Modulating the Buried Interfaces of Perovskite Solar Cells.

In perovskite solar cells (PSCs), tin dioxide (SnO2) is a highly effective electron transport material. On the other hand, the low intrinsic conductivity of SnO2, the high trap-state density on the surface and bulk of SnO2, and inadequate interface contacts between SnO2 and perovskite significantly impact device performance. Herein, small-molecule copper(II) chloride (CuCl2) is introduced into the SnO2 dispersion, which inhibits the agglomeration of SnO2 colloids and improves the quality of the electron transport layer. Furthermore, the introduction of CuCl2 optimizes the energy-level array between the ETL and perovskite layer (PVK) and passivates the anion/cation defects in SnO2, perovskite, and their interface, realizing the systematic modulation of the photoelectronic properties of the ETLs and PVKs as well as the PVK/ETL. As a result, the CuCl2-opmized PSC exhibits an impressive power conversion efficiency of 23.71%, along with improved stability.

High-performance self-powered ultraviolet photodetector based on a ZnO/CuPc inorganic/organic heterojunction.

A self-powered photodetector (PD) based on n-type ZnO/p-type small-molecule copper(ii) phthalocyanine (CuPc) inorganic/organic heterojunction film deposited on FTO substrate was constructed by simple solution spin-coating and thermal evaporation technology. The designed heterojunction device exhibits typical photoresponse behavior under zero bias, indicating that the device possesses a self-powered characteristic. This may benefit from the formation of a built-in electric field in the heterojunction, which can effectively separate electron-hole pairs. Specifically, the optimal performances of the device appear at a wavelength of 365 nm and light intensity of 0.03 mW cm-2, achieving on/off ratio of ∼245.88 (29.88), responsivity (Rp) of ∼227.11 mA W-1 (0.39 mA W-1), detectivity (D*) of ∼7.63 × 1011 Jones (∼7.53 × 109 Jones) and EQE of ∼77.23% (0.14%) at +2 V (0 V) bias voltage. In addition, the device has potential application in weak light detection. Therefore, the construction of inorganic/organic heterojunctions may provide a feasible strategy for the development of high-performance, self-powered and wavelength-selective PDs.

Current and Future of "Turn-On" Based Small-Molecule Copper Probes for Cuproptosis.

Increasing evidence shows that abnormal copper (Cu) metabolism is highly related to many diseases, such as Alzheimer's disease, Wilson's disease, hematological malignancies and Menkes disease. Very recently, cuproptosis, a Cu-dependent, programmed cell death was firstly described by Tsvetkov et al. in 2022. Their findings may provide a new perspective for the treatment of related diseases. However, the concrete mechanisms of these diseases, especially cuproptosis, remain completely unclear, the reason of which may be a lack of reliable tools to conduct highly selective, sensitive and high-resolution imaging of Cu in complex life systems. So far, numerous small-molecular fluorescent probes have been designed and utilized to explore the Cu signal pathway. Among them, fluorescence turn-on probes greatly enhance the resolution and accuracy of imaging and may be a promising tool for research of investigation into cuproptosis. This review summarizes the probes developed in the past decade which have the potential to study cuproptosis, focusing on the design strategies, luminescence mechanism and biological-imaging applications. Besides, we put forward some ideas concerning the design of next-generation probes for cuproptosis, aiming to tackle the main problems in this new field. Furthermore, the prospect of cuproptosis in the treatment of corresponding diseases is also highlighted.

In Situ Surface Modification Enables High Stability and Optoelectrical Performance for a Self‐powered Photodetector

AbstractPerovskite single crystals (SCs) have gained significant interest in various applications owing to their superior optoelectrical and physical characteristics as compared to polycrystalline films. However, a considerable portion of incident light is typically reflected at the surface of perovskite SCs, leading to insufficient light absorption within the crystal bulk, ultimately resulting in reduced performance of SC‐based photodetectors. In the present work, an inverted pyramid‐shaped structure is in situ introduced on the surface of an MAPbBr3 SC during the crystal growth process, which can reduce light reflection in the surface region and enhance light absorption of the SC. Additionally, the hydrophobic small molecule copper (II) phthalocyanine (CuPc) is thermally evaporated onto the SC, forming a CuPc/MAPbBr3 heterojunction for the first time. The CuPc/pyramid‐shaped MAPbBr3 heterojunction‐based photodetector exhibits self‐powered characteristics and superior optoelectrical performance, achieving a photocurrent of greater than 10−5 A (10−7 A), a responsiveness of 257 mA W−1 (8.84 mA W−1), and a detection rate of 2.98 × 1012 Jones (1.02 × 1011 Jones) at −2 V (0 V) bias. Simultaneously, the device demonstrates excellent long‐term stability under high humidity conditions, retaining 90.5% of its initial photocurrent even after 60 days in a 60–80% humidity environment.

Mechanisms of IRF2BPL-related disorders and identification of a potential therapeutic strategy.

The recently discovered neurological disorder NEDAMSS is caused by heterozygous truncations in the transcriptional regulator IRF2BPL. Here, we reprogram patient skin fibroblasts to astrocytes and neurons to study mechanisms of this newly described disease. While full-length IRF2BPL primarily localizes to the nucleus, truncated patient variants sequester the wild-type protein to the cytoplasm and cause aggregation. Moreover, patient astrocytes fail to support neuronal survival in coculture and exhibit aberrant mitochondria and respiratory dysfunction. Treatment with the small molecule copper ATSM (CuATSM) rescues neuronal survival and restores mitochondrial function. Importantly, the invitro findings are recapitulated invivo, where co-expression of full-length and truncated IRF2BPL in Drosophila results in cytoplasmic accumulation of full-length IRF2BPL. Moreover, flies harboring heterozygous truncations of the IRF2BPL ortholog (Pits) display progressive motor defects that are ameliorated by CuATSM treatment. Our findings provide insights into mechanisms involved in NEDAMSS and reveal a promising treatment for this severe disorder.

Bracing copper for the catalytic oxidation of C–H bonds

A structural unit found in the active site of some copper proteins, the histidine brace, is comprised of an N-terminal histidine that chelates a single copper ion through its amino terminus NH2 and the π–N of its imidazole side chain. Coordination is completed by the τ-N of a further histidine side chain, to give an overall N3 T-shaped coordination at the copper ion. The histidine brace appears in several proteins, including lytic polysaccharide monooxygenases LPMOs and particulate methane monooxygenases pMMOs, both of which catalyse the oxidation of substrates with strong C–H bonds (bond dissociation enthalpies ~100 kcal mol–1). As such, the copper histidine brace is the focus of research aimed at understanding how nature catalyses the oxidation of unactivated C–H bonds. In this Perspective, we evaluate these studies, which further give bioinspired direction to coordination chemists in the design and preparation of small molecule copper oxidation catalysts. The histidine brace found in certain copper oxidases enables the oxidation of strong C–H bonds in organic substrates. This Perspective highlights and discusses the possible structural and electronic features of this motif and how these features underlie its role in challenging oxidative catalysis.

Altered serum copper homeostasis suggests higher oxidative stress and lower antioxidant capability in patients with chronic hepatitis B.

Copper homeostasis can be altered by inflammation. This study aimed to investigate the alteration of serum copper homeostasis and to explore its clinical significance in patients with chronic hepatitis B (CHB).Thirty-two patients with CHB and 10 aged- and sex-matched healthy controls were recruited. Analyses included serum levels of total copper (TCu), copper ions (Cu+), small molecule copper (SMC), ceruloplasmin (CP), Cu/Zn superoxide dismutase 1 (SOD1), urinary copper, and the activities of serum CP and SOD1.The serum TCu and urinary copper levels in patients with CHB were significantly higher than the controls (P = .04 and .003), while the serum Cu+ was lower than the controls (P = .0002). CP and SOD1 activities in the serum were significantly lower in patients with CHB compared to controls (P = .005) despite higher serum concentrations. In addition, serum alanine aminotransferase inversely correlated with serum CP activity (P = .0318, r = −0.4065).Serum copper homeostasis was altered in this cohort of patients with CHB. The results suggest increased oxidative stress and impaired antioxidant capability in patients with CHB, in addition to necroinflammation. These results may provide novel insights into the diagnosis and treatment of patients with CHB.

Serum Copper Homeostasis in Hypertensive Intracerebral Hemorrhage and its Clinical Significance.

This study was to investigate the alterations of serum copper homeostasis after hypertensive intracerebral hemorrhage (ICH), which is not yet clear. We recruited 85 hypertensive ICH patients and determined their serum levels of total copper (TCu), small molecule copper (SMC), and ceruloplasmin (Cp). Sera from 32 healthy persons and 12 primary hypertension patients were collected and analyzed as well. Serum TCu levels in ICH patients were tested at three time points (on admission, day 3, and day 7) and found to be higher than that in hypertension patients (p < 0.05). The serum SMC levels in hypertension patients and ICH patients at three time points were higher than that in healthy controls (p < 0.05). Higher serum SMC levels on days 3 and 7 were associated with death in the hospital. Additionally, higher serum SMC levels on the seventh day were associated with poor outcome at discharge. High serum Cp levels on admission, as well as low serum Cp levels on the seventh day, were associated with death in the hospital (p = 0.002 and p = 0.034, respectively). Our findings indicated that declines in serum Cp and increases in serum SMC are correlated with lethal or poor outcome in hypertensive ICH patients, possibly as a result of contributions to secondary injury of brain after hemorrhage due to impairment of iron transport and enhanced oxidative stress.

Structural varieties in Copper(II) aryl-carboxylates/-sulphonates with N-donor ligands

Coordination chemistry- the clothing of metal ion, is a branch of inorganic chemistry which encompasses chemistry, biology, environment and material science having a direct relevance to life of a human being. Supramolecular chemistry- looking beyond a molecule has developed as a full fledged discipline out of coordination chemistry and consists of two facets: crystal engineering and molecular recognition. It involves role of non-covalent interactions like hydrogen bonding, π⋯π stacking etc. in stabilizing supramolecular assemblies. Copper is one of the essential elements of life. Its deficiency or excess causes diseases such as Parkinson, Alzimer, Wilson disease etc. Therefore, the synthesis and characterization of small molecule copper(II) complexes is a topic of immense interest to inorganic chemists so as to understand the role of copper in biological system and its applications in synthesis, chirality transfer, spin cross-over etc. With this in mind, in this review, we present our recent findings in developing synthetic methodologies and single crystal X-ray structural studies of copper(II) complexes of arylcarboxylates/ -sulfonates/ NSAIDs with various nitrogen-donor ligands.

Small Molecule–Polymer Composite Hole-Transporting Layer for Highly Efficient and Stable Perovskite Solar Cells

Effective and stable hole-transporting materials (HTMs) are necessary for obtaining excellent planar perovskite solar cells (PSCs). Herein, we reported a solution-processed composite HTM consisting of a polymer poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and a small-molecule copper phthalocyanine-3,4',4″,4‴-tetrasulfonated acid tetrasodium salt (TS-CuPc) with optimized doping ratios. The composite HTM is crucial for not only enhancing the hole transport and extraction but also improving the perovskite crystallization. In addition, the composite HTM can weaken the indium tin oxide erosion by reducing the acidity and increasing the dispersibility of the PEDOT:PSS aqueous dispersion via incorporating suitable TS-CuPc. Consequently, a highly efficient device was fabricated with a power conversion efficiency (PCE) of 17.29%. Its short-circuit current (JSC) is 22.23 mA/cm2, and its open-circuit voltage (VOC) is 1.01 V. Meanwhile, it exhibited a higher fill factor (FF) of 77% and improved cell stability. The developed composite HTM provides a good potential anode interfacial layer for fabricating outstanding PSCs.

Small Molecule Copper and Its Relative Metabolites in Serum of Cerebral Ischemic Stroke Patients

Copper is a strong pro-oxidant. The most important pro-oxidative form in serum is small molecule copper (SMC), which is copper that is loosely bound to small molecules, such as amino acids and polypeptides. The association between copper and atherosclerotic diseases has been confirmed, but that between SMC and cerebral ischemic stroke (CIS), one of the most principal manifestations and causes of death of atherosclerotic disease, is not yet clear. We recruited 45 CIS patients and 25 age- and gender-matched healthy controls. We detected their serum levels of SMC, total copper, homocysteine (Hcy), and ceruloplasmin (CP), as well as urinary total copper, and analyzed the relationship of SMC with these aforementioned metabolites or compounds in CIS patients. SMC was 4.2 ± .5 µg/L and 2.1 ± .9 µg/L; total copper in sera was 1345.5 ± 308.2 µg/L and 1180.3 ± 134.0 µg/L; and total copper in urine was 27.6 ± 9.3 µg/L and 18.8 ± 8.1 µg/L in patients and controls, respectively (all P < .05). Serum CP activity in CIS patients was 59.92 ± 12.11 U/L versus 37.76 ± 5.71 U/L in controls (P = .0001). The concentration of SMC was positively correlated with CP activity, Hcy concentration in sera, and urinary total copper. The serum level of SMC and total copper is remarkably elevated, and SMC positively correlates with Hcy, CP activity, and urinary total copper in CIS patients.

Experimental study and analytical modeling of the channel length influence on the electrical characteristics of small-molecule thin-film transistors

Bottom-contact p-type small-molecule copper phthalocyanine (CuPc) thin film transistors (TFTs) with different channel lengths have been fabricated by thermal evaporation. The influence of the channel length on the current–voltage characteristics of the fabricated transistors were investigated in the linear and saturation regimes. The devices exhibit excellent p-type operation characteristics. Results show that devices with smaller channel length (L=2.5μm and 5μm) present the best electrical performance, in terms of drain current value, field effect mobility and subthreshold slope. Saturation field-effect mobilities of 1.7×10−3cm2V−1s−1 and 1×10−3cm2V−1s−1 were obtained for TFTs with channel lengths of L=2.5μm and L=5μm, respectively. Transmission line method was used to study the dependence of the contact resistance with the channel length. Contact resistance becomes dominant with respect to the channel resistance only in the case of short channel devices (L=2.5μm and 5μm). It was also found that the field effect mobility is extremely dependent on the channel length dimension. Finally, an analytical model has been developed to reproduce the dependence of the transfer characteristics with the channel length and the obtained data are in good agreement with the experimental results for all fabricated devices.

Dyes in Vertically Aligned Carbon Nanotube Arrays for Solar Cell Applications

ABSTRACTThe infiltration of dissolved dyes into vertically aligned carbon nanotube arrays (va-CNT) is reported. The ultra hydrophobic surface of the CNT forest can be wetted and hence infiltrated for an appropriate choice of solvent. The dye-infiltrated CNT array forms a well ordered bulk-heterojunction structure for organic solar cells in which the CNT can act as a large electrode or, for appropriate energy levels, as an acceptor material. Derivatives of the small molecule copper phthalocyanine or the polymer poly(3-hexylthiophene) were used as dyes. Drop coating was chosen as the infiltration technique resulting in a completely embedded CNT forest. Field emission secondary electron microscopy analysis illustrates the final layer quality. Common electrical characterization under AM1.5 illumination proves photosensitivity and implies photovoltaic behavior of the composite.

Macrocyclic [CuI/II(bite)]+/2+ (bite = biphenyldiimino dithioether): An Example of Fully-Gated Electron Transfer and Its Biological Relevance1

Template condensation of 2,2‘-diaminobiphenyl, 1,4-bis(2-formylphenyl)-1,4-dithiabutane, and copper(II) tetrafluoroborate yields the new macrocyclic compound [CuI(bite)](BF4) (bite = biphenyldiimino dithioether). [CuI(bite)]BF4 crystallizes in the orthorhombic space group P212121 with a = 14.379(3) Å, b = 21.370(3) Å, c = 8.046(2) Å, V = 2534.7(7) Å3, Z = 4, R1 = 0.045, and R2 = 0.048. The X-ray structure of [CuI(bite)](BF4) reveals distorted tetrahedral N2S2 coordination about copper, with one unusually short Cu−S(thioether) bond of 2.194(2) Å. Oxidation of [CuI(bite)](BF4) with nitrosyl tetrafluoroborate gives [CuII(bite)](BF4)2. [CuII(bite)](BF4)2 crystallizes in the tetragonal space group I41/a with a = 11.640(2) Å, c = 39.527(3) Å, V = 5355.6(7) Å3, Z = 8, R1 = 0.061, and R2 = 0.063. X-ray crystallography of [CuII(bite)](BF4)2 reveals an approximately square planar CuN2S2 structure with two distant axial BF4- anions (Cu−F 2.546(4) Å) completing a “pseudo-octahedral” coordination sphere. Comparative EXAFS studies of solid samples and acetonitrile solutions of [CuI(bite)](BF4) and [CuII(bite)](BF4)2 demonstrate that the primary coordination environments of both species are the same in solution as in the solid. Copper(I/II) electron self-exchange kinetics measured by 1H NMR line broadening of [CuI(bite)]+ in the presence of [CuII(bite)]2+ reveal an overall first-order process with a rate constant of 21.7(1.9) s-1 at 295 K in acetone-d6. This result represents the first example of fully-gated electron transfer by small-molecule copper(I). The gating process likely involves inversion at sulfur and the tetrahedral → square planar structural change coincident with electron transfer. Variable-temperature 1H NMR coalescence temperatures for methylene ligand protons of [CuI(bite)](BF4) (287 K) demonstrate possible correlation of fast electron transfer with high ligand mobility for this and related small-molecule copper(I/II) couples. Comparison with other small-molecule copper systems also reveals that fast electron transfer is not always observed with coordination-number-invariance and conserved geometry during redox turnover, contrary to popular interpretations of the entatic state hypothesis for blue-copper protein active sites.