Formation Of Coordination Bonds Research Articles

Artificial Protein Cages Assembled via Gold Coordination.

Artificial protein cages made from multiple copies of a single protein can be produced such that they only assemble upon addition of a metal ion. Consequently, the ability to remove the metal ion triggers protein-cage disassembly. Controlling assembly and disassembly has many potential uses including cargo loading/unloading and hence drug delivery. TRAP-cage is an example of such a protein cage which assembles due to linear coordination bond formation with Au(I) which acts to bridge constituent proteins. Here we describe the method for production and purification of TRAP-cage.

Design and search for prospective diuretics (CA II Inhibitors) among aroylhydrazones of esters quinone oxime using in silico and in vivo methodology

The design and search for new selective inhibitors of CA II with a better pharmacological profile, which would cause minimal electrolyte disturbances in the body, remains an urgent problem of medical chemistry and pharmacology today. It is important that the discovered new classes of inhibitors do not always contain the main “pharmacophoric” function (sulfamide), which is characteristic of “classic” drugs (Acetazolamide, Methazolamide, Ethoxzolamide, Dorzolamide and others), but are derivatives of phenols, polyamines, coumarins/thiocoumarins, ureas, thioureas, hydroxamates, etc. These molecules also bind in the active site of the enzyme, but do not interact directly with the catalytic zinc ion or interact through zinc-coordinated water molecules/hydroxide ion. However, this leads to an increase in their selectivity and, as a result, pharmacological action. Continuing the search for compounds that affect urination, we were interested in aroylhydrazones of esters of quinone oxime. Firstly, they are characterized by certain structural features (dynamic and geometric isomerism); secondly, they exhibit redox properties; thirdly, the presence of aromatic fragments makes it possible to create a voluminous combinatorial library for analysis. These compounds are ligands in complexation reactions, and an additional increase in the number of hydrogen acceptors in the molecule due to structural modification will improve ligand-enzymatic interactions with carbonic anhydrase (CAII) and, as a result, reveal new promising diuretics. The aim – design and search for potential diuretics (CA II inhibitors) among aroylhydrazones of esters of quinone oxime using in silico, traditional synthesis and in vivo methodologies. Methods of organic synthesis, physico-chemical methods of analysis of organic compounds (NMR 1H-spectroscopy, elemental analysis). Prediction of affinity to the biological target, prediction of toxicity and lipophilicity of the combinatorial library of benzohydrazides O-aroyl esters of quinone oxime using computer services. The study of compounds affecting the excretory function of rat kidneys was carried out according to the generally accepted method of E.B.Berkhin with water load. The investigation of the probable mechanism was carried out using flexible molecular docking, as an approach to search for molecules that have affinity for human carbonic anhydrase type II (CA II). Macromolecular data of the crystal structure of CA II (PDB ID – 3HS4) were downloaded from the Protein Data Bank (PDB). The design was developed and the search for diuretic agents among benzohydrazides of O-aroyl esters of quinone oximes was developed using in silico methods (prediction of affinity, lipophilicity, toxicity and enzyme-ligand interactions), traditional organic synthesis, and in vivo methods (effect on excretory function of rat kidneys). The synthesis of benzohydrazides of O-aroyl esters of quinone oxime was carried out by the interaction of aroylhydrazines with 4-[(aroylimino)]cyclohexa-2,5-dien-1-ones. The structure of the synthesized compounds was confirmed by elemental analysis and 1H NMR spectra. Studies of the effect of synthesized compounds on the excretory function of rat kidneys allowed us to identify a number of promising compounds among aroylhydrazones of quinonexime esters, which increase daily diuresis by 54.2-352.8% compared to the control group. At the same time, it was established that the most active was N'-(4-[(2-chlorobenzoyloxy)imino]cyclohexa-2,5-dien-1-ylidene)-3-nitrobenzohydrazide, which increased daily diuresis by 352.8% in comparison with the control group, while exceeding the effect of “Hydrochlorothiazide” (170.8%). The developed and implemented strategy for the search for diuretics among benzohydrazides of O-aroylesters of quinone oxime allowed the identification of an effective compound, which in terms of diuretic effect exceeds the comparison drug “Hydrochlorothiazide”. Visualization of the molecular docking of the active compounds showed that their geometry makes it difficult to place them in the pocket of the active site of CA II, but the pronounced diuretic effect can also be associated with their ability to form coordination bonds with the zinc cation. The obtained results justify the further targeted search for potential diuretics among this class of compounds for a more detailed understanding and study of the mechanism of action.

HOMO-LUMO energy gaps of complexes of transition metals with single and multi-ring aromatics

Optical and electronic properties of aromatics and their clusters are critical to interpreting phenomena ranging from flame-formed nanoparticles to interstellar dust. These properties are also important to their applications as organic semiconductor materials. Aromatic hydrocarbons often form coordination bonds with metal atoms and cations, forming complexes with electronic properties that differ from their parent aromatics. Metal incorporation to aromatics allows access to a versatile range of optical and electronic properties via the modulation of their band gaps. Here, we investigate the binding of four fourth-row transition metals (titanium, chromium, iron, and nickel) with four aromatic molecules (benzene, naphthalene, pyrene, and coronene), and the HOMO-LUMO energy gap of the metal-aromatic complexes using density functional theory calculations. Neutral and cationic (1+ and 2+) complexes are studied at different geometrical and spin configurations, and their binding energies and HOMO-LUMO gaps are computed for the ground state. It is observed that binding with metals can reduce the HOMO-LUMO gap of the aromatics significantly, and the gap energy of the metal-aromatic complexes is closely correlated with their ionization energy. The number of possible transitions from occupied to unoccupied molecular orbitals was also calculated, showing similar spectral energy features for naphthalene, pyrene, and coronene with and without metal incorporation.

Strengthening and toughening mechanisms induced by metal ion cross-linking in wet-drawn bacterial cellulose films

Cellulose nanofibril (CNF) has become a renewable and sustainable building block for functional and structural materials. In this study, combining chemical structure analyses, mechanical experiments, and first principle calculations, we elaborate on the strengthening and toughening mechanisms for the wet-drawn bacterial cellulose (BC) films that contain metal ion crosslinks. Wet-drawing assists the alignment of CNFs, and multivalent metal ion cross-linking further improves the inter-fibril interactions. BC films cross-linked with Na+, Ca2+, Cu2+, Al3+, and Fe3+ all demonstrate improved mechanical strength than the as-received samples. Density functional theory (DFT) calculations reveal that besides the electrostatic forces between the metal ions and the adjacent carboxylate oxygen atoms, Cu2+ and Fe3+ can also form coordination bonds with the adjacent carboxylate oxygen atoms. Among all the five metal ions tried herein, Fe3+ introduces the strongest cross-links between nanofibrils through coordination bonds and electrostatic forces. The BC films cross-linked with Fe3+ exhibit high tensile strength and toughness of 451.51 MPa and 8.19 MJ∙m−3, respectively. The underlying mechanisms discovered herein open new possibilities for utilizing natural fibers.

Highly Exposed NH2 Edge on Fragmented g-C3 N4 Framework with Integrated Molybdenum Atoms for Catalytic CO2 Cycloaddition: DFT and Techno-Economic Assessment.

This study focuses on the applicability of single-atom Mo-doped graphitic carbon nitride (GCN) nanosheets which are specifically engineered with high surface area (exfoliated GCN), NH2 rich edges, and maximum utilization of isolated atomic Mo for propylene carbonate (PC) production through CO2 cycloaddition of propylene oxide (PO). Various operational parameters are optimized, for example, temperature (130°C), pressure (20bar), catalyst (Mo2 GCN), and catalyst mass (0.1g). Under optimal conditions, 2% Mo-doped GCN (Mo2 GCN) has the highest catalytic performance, especially the turnover frequency (TOF) obtained, 36.4 h-1 is higher than most reported studies. DFT simulations prove the catalytic performance of Mo2 GCN significantly decreases the activation energy barrier for PO ring-opening from 50-60 to 4.903kcal mol-1 . Coexistence of Lewis acid/base group improves the CO2 cycloaddition performance by the formation of coordination bond between electron-deficient Mo atom with O atom of PO, while NH2 surface group disrupts the stability of CO2 bond by donating electrons into its low-level empty orbital. Steady-state process simulation of the industrial-scale consumes 4.4 ton h-1 of CO2 with PC production of 10.2 ton h-1 . Techno-economic assessment profit from Mo2 GCN is estimated to be 60.39 million USD year-1 at a catalyst loss rate of 0.01wt% h-1 .

2,6‐Di(1H‐tetrazol‐1‐yl)pyridine and its cupric chloride complex

Abstract2,6‐Di(1H‐tetrazol‐1‐yl)pyridine (DTP) was prepared by a four‐stage procedure, including step‐by‐step heterocyclization of both amino groups of 2,6‐diaminopyridine with triethyl orthoformate and sodium azide. According to quantum‐chemical calculations and single crystal X‐ray diffraction data, DTP crystallizes in the form of the thermodynamically most stable conformer and has an almost flat molecular geometry. DTP was found to react with CuCl2 ⋅ 2H2O in ethanol to give the [Cu(DTP)Cl2(H2O)]n complex, which is a 1D coordination polymer, formed at the expense of bridging DTP ligand via the tetrazole ring nitrogen atoms N4. Possible coordination cites in DTP molecule are discussed using the data of quantum chemical calculations. The pyridine ring nitrogen atom of DTP does not participate in the formation of either coordination or intermolecular hydrogen bonds. This is explained by the results of quantum chemical calculations showing that this atom is less basic than N3 and N4 atoms of DTP molecule.

TiO2 nanoarrays/Au nanoparticles/PProDOT-Py hybrid heterojunction UV photodetector

In this paper, a novel D-A-D type conducting polymer (PProDOT-Py) with pyridine as acceptor unit and 3,4-propanedioxythiophene as donor unit was prepared for heterojunction ultraviolet (UV) photodetector based on TiO 2 NRs/Au NPs. The effect of PProDOT-Py on the UV photodetection properties was deeply discussed. The results showed that PProDOT-Py was unevenly dispersed on TiO 2 NRs in the form of cross-linked network, and there were coordination bonds between TiO 2 NRs and PProDOT-Py. The matching of the energy levels between PProDOT-Py and TiO 2 was helpful for formation of heterojunction hybrid.The maximum rectification ratio of TiO 2 NRs/Au NPs/PProDOT-Py was 54 under bias voltage of −2 to 2 V, implying that the p-n heterojunction in the internal structure of TiO 2 NRs/Au NPs/PProDOT-Py. The Fermi level of TiO 2 NRs was changed by the presence of PProDOT-Py, which generated the p-n heterojunction for producing strong inherent electric field. In addition, D* and I photo /I dark of UV photodetector based on TiO 2 NRs/Au NPs/PProDOT-Py were 1.067 × 10 13 Jones and 17857.14 (2 V), respectively. Under the condition of self-power supply, the device has an ultrafast response time of 0.06 s. • ProDOT-Py was synthesized for the first time. • TiO 2 NRs/Au NPs/PProDOT-Py composite shows superior UV detection performance under 2V bias voltage. • PProDOT-Py can form coordination bond with TiO 2 and Au NPs can strongly interact with PProDOT-Py.

Intramolecular electrochemiluminescence resonance energy transfer by grafting Ru-complexes on donor ligand-rich metal-organic framework nanoplate for ultrasensitive detection of microRNA

Electrochemiluminescence resonance energy transfer (ECL-RET) is an effective method to improve the ECL performance of materials. However, the intermolecular ECL-RET systems still suffered from low ECL-RET efficiency. To improve the ECL-RET efficiency, we established a high-efficient intramolecular ECL-RET system (Ru-Zr12-adb, H2adb = 4,4′-(9,10-anthracenediyl)dibenzoic acid), in which Zr12-adb metal-organic framework (MOF) nanoplate was employed as the donor to enhance the ECL intensity of Ru(bpy)2(mcbpy)2+ (acceptor). Because the high-ordered porous frameworks of Zr12-adb nanoplate not only coordinatively immobilized abundant Ru(bpy)2(mcpbpy)2+ but also realized exact and short-distance intramolecular ECL-RET, thus Ru-Zr12-adb possessed strong ECL emission. Moreover, the easy formation of coordination bonds makes MOFs an ideal platform for conveniently building high-efficient ECL-RET systems, promoting their broad application in ECL sensors. Given the aforementioned merits, Ru-Zr12-adb was chosen as a high-efficient ECL beacon coupled with the catalytic hairpin assembly and double-end DNAzyme-driven DNA walker recycling amplification to build an ultra-sensitive sensor for microRNA-21 assay, which showed wide linearity (10 aM to 100 pM) with a detection limit of 1.9 aM. Collectively, the work showed that using MOFs to immobilize energy donors and energy acceptors concurrently was a simple effective method to build high-efficient ECL-RET materials, which offered new opportunities for fabricating ultrasensitive ECL sensors.

Copper sulfide anchored MXene improving photo-responsive self-healing polyurethane with enhanced mechanical and antibacterial properties

Diseases caused by bacterial infection are becoming a major threat to human health. Therefore, developing efficient antibacterial materials is of great significance in improving medical care and protecting people's health. In this work, an accordion-like structural Ti3C2@CuS was synthesized by copper sulfide (CuS) nanospheres anchored firmly on the surface of Ti3C2Tx via the hydrothermal method. The multilayer Ti3C2@CuS becomes few-layered nanosheets after ultrasonic treatment, which have an enjoyable dispersion in the polyurethane (PU) matrix. PU and the released Cu2+ from Ti3C2@CuS are firmly linked by a coordination bond, which improves the mechanical properties and thermal stability of Ti3C2@CuS-PU and reduces the heavy metal ion pollution by blocking the Cu2+ released by forming coordination bonds. Moreover, Ti3C2@CuS-PU exhibits an excellent self-healing performance after 30 tensile cycles. Additionally, Ti3C2Tx and CuS could improve the separation efficiency of the electron-hole pairs of CuS to produce more reactive oxygen species (ROS) to kill bacteria. Ti3C2@CuS-PU maintains a highly long-term sterilization ability of more than 90 % in 30 days because of the synergistic effect of the sustained release of copper ions, the elevated ROS production ability, and the excellent dispersion of Ti3C2@CuS in PU. This work demonstrates a simple and promising route for designing multifunctional antibacterial self-healing materials.

Preparation of a Chitosan/Coal Gasification Slag Composite Membrane and Its Adsorption and Removal of Cr (VI) and RhB in Water.

At present, there are many kinds of pollutants, including dyes and heavy metal ions, in wastewater. It is very important to develop adsorbents that can simultaneously remove heavy metal ions and dyes. In this study, a renewable composite membrane material was synthesized using chitosan and treated coal gasification slag. The Cr (VI) maximum adsorption capacity of the composite membrane was 50.0 mg/L, which was 4.3~8.8% higher than that of the chitosan membrane. For the adsorption of RhB, the removal rate of the chitosan membrane was only approximately 5.0%, but this value could be improved to 95.3% by introducing coal gasification slag. The specific surface area of the chitosan membrane could also be increased 16.2 times by the introduction of coal gasification slag. This is because coal gasification slag could open the nanopores of the chitosan membrane (from 80 μm to 110 μm). Based on the adsorption kinetics and adsorption mechanism analysis, it was found that the adsorption of Cr (VI) occurred mainly through the formation of coordination bonds with the amino groups on the molecular chains of chitosan. Meanwhile, RhB adsorption occurred through the formation of hydrogen bonds with the surface of coal gasification slag. Additionally, coal gasification slag can improve the mechanical properties of the chitosan membrane by 2.2 times, which may facilitate the practical application of the composite membrane. This study provides new insight into the adsorbent design and the resource utilization of coal gasification slag.

Enhanced the structural, optical, electrical and magnetic properties of PEO/CMC blend filled with cupper nanoparticles for energy storage and magneto-optical devices

Nanocomposite samples of polyethylene oxide (PEO) and carboxymethyl cellulose (CMC) blend filled with different concentrations of cupper nanoparticles (Cu NPs) were prepared via the casting route. The components of the blend were miscible as shown by the X-ray diffraction (XRD) and FTIR measurements. Transmission electron microscope (TEM) image showed that the Cu NPs have diameters in the range from 4.09 to 19.65 nm. Fourier transform infrared (FTIR) spectra showed the complexation between polymeric matrix and Cu NPs through the formation of hydrogen and coordination bonds. Ultraviolet/visible (UV/vis.) spectra showed an improvement in the optical features for the filled samples. The scanning electron microscope (SEM) micrographs indicted the smooth and homogeneous surface of nanocomposite samples, reflecting the homogeneity of this blend that was affected after the filling process. The differential scanning calorimetry (DSC) curve displayed that the pure blend had a single glass transition temperature (Tg), indicating that the blend components were miscible. Also, DSC exhibited an improvement in the thermal stability of the polymeric matrix after the addition of Cu NPs. The AC conductivity was increased with increasing content of Cu NPs. The highest value of AC conductivity for the pristine sample was 4.57 × 10−8 S/cm at 20 MHz that was increased to 3.71 × 10-6 S/cm for nanocomposite (1.60 wt % Cu NPs) at room temperature due to the increase of charge carrier number. The complex permittivity (ε*) and electric modulus spectra were also studied. At high frequency, the decreasing trend of permittivity was attributed to dipoles orientation. The VSM studies of filled samples depicted the hysteresis loops of the ferromagnetic characteristics. These results denote that PEO/CMC/Cu NPs films can be used in electromagnetic components, energy storage devices as well as in magneto-optical fields.

High-strength super-hydrophobic double-layered PBO nanofiber-polytetrafluoroethylene nanocomposite paper for high-performance wave-transparent applications

Poly(p-phenylene-2,6-benzobisoxazole) nanofiber (PNF) paper is facing unprecedented challenges in enhancing the interaction between the PNFs and improving its hydrophobicity. In this work, a sol–gel film transformation approach was developed to fabricate high-strength PNF paper. Iron ions formed coordination bonds between PNFs to obtain a preforming three-dimensional, interconnective nanofiber network. Subsequently, polytetrafluoroethylene (PTFE) particles were sprayed onto the surface of the paper, followed by thermal treatment to obtain double-layered PTFE-P/PNF nanocomposite paper. The nanocomposite paper presents incredible tensile strength (271.6 MPa, increased by 52.9%), folding endurance, super-hydrophobicity, and self-cleaning performances. Moreover, it exhibits low dielectric constant (2.06) and dielectric loss tangent (0.0133) values. According to the wave-transparent model for a double-layered dielectric established by Maxwell’s equations, the wave-transparent coefficients of electromagnetic waves incident from both sides of the paper are 97.6% (PNF side) and 96.0% (PTFE/P(S-co-BCB-co-MMA) side), respectively. The PTFE-P/PNF nanocomposite paper possesses great potential in the fields of wave-transparent applications.

Surface Coating with Naphthalene Trisulfonate/Hafnium(IV) Complexes: Versatility and Post-Functionalization.

Naphthalene trisulfonate is found to have versatile surface coating capability when combined with hafnium(IV) ions, thereby forming complexes. Solid substrates such as titanium/titanium dioxide, glass, and nylon immersed in a solution of naphthalene trisulfonate and HfIV produces naphthalene trisulfonate/HfIV complex coating. The coating is not produced when the HfIV ions are absent or when naphthalene monosulfonate replaces naphthalene trisulfonate; this indicates the significance of HfIV ions and multiple sulfonates in this coating system. The versatile surface coating property of naphthalene trisulfonate/HfIV complexes is attributed to the coexistence of hydrophobic aromatic and hydrophilic side groups in naphthalene trisulfonate. Additionally, HfIV ion-mediated cross-linking reactions between naphthalene trisulfonate molecules induce molecular assembly, facilitating versatile surface coating. Post-functionalization of the coating is accomplished through additional HfIV-mediated coordinate bond formation; alginate and λ-carrageenan are successfully grafted onto the coating for nonbiofouling applications.

Adsorption of Cd2+ from synthetic wastewater by modified leaves of Eupatorium adenophorum and Acer oblongum: thermodynamics, kinetics and equilibrium studies

AbstractHeavy metals cause outrageous ecological risks when released into the environment from many point and non-point sources. Biosorbents prepared from the leaves of Eupatorium adenophorum (AEA) and Acer oblongum (AAO) were used as practical solutions to remove the toxic heavy metal cadmium (Cd2+) from wastewater. Biosorption of Cd2+ was investigated using AEA and AAO biomass under batch conditions. The effect of operating variables like temperature, contact time, the pH impact, and initial metal concentration and biosorbent portion on Cd2+ removal has been studied. The optimal pH and the sorbent dosage were found to be 7.0 and 2.0 g L−1, respectively, and removal efficiency attained was 93.3% with an equilibrium removal time of 90 min. The equilibrium uptake of Cd2+ was evaluated by Freundlich, Langmuir, and Temkin isotherm models. The Langmuir isotherm model was proved fit confirming single layer of sorption. The biosorption of Cd2+ onto activated AEA and AAO biomass achieved were 45.45 mg g−1 and 44.64 mg g−1 respectively. The adsorption affinity of AEA toward Cd2+ was discovered a lot more prominent than AAO biomass. The kinetic data of Cd2+ biosorption onto activated AEA and AAO, fitted with a pseudo-second-order well with higher values of R2 (> 0.99). Thermodynamics disclosed that the adsorption process was spontaneous (∆G0 < 0), endothermic (∆H0 > 0), and feasible (ΔS0 > 0). The adsorption of Cd2+ onto AEA was more exothermic and spontaneous than the AAO biosorbent. Additionally, FT-IR and SEM analysis uncovered that Cd2+ were adsorbed onto selected biomassdue to –NH–, –COOH, –OH, and –NH2 groups. Ionic, coordination bond formation, and electrostatic interaction with Cd2+ demonstrated that they were promising biosorbent for wastewater treatment.

Bimetallic synergy boost TCPP(Ni)-Co MOF as the high-performance electrochemical sensor for enhanced detection of trace theophylline

A bimetallic porphyrin MOF TCPP(Ni)-Co has been synthesized by the combination of reflux method and hydrothermal method. Due to the inherent conjugated ligand TCPP and the synergistic effect between metal center Co2+ and Ni2+, the TCPP(Ni)-Co MOF could work as the high-performance electrochemical sensor by the modification on the GCE. TCPP(Ni)-Co@GCE could realize the detection of trace theophylline with high sensitivity, fast response time (less than 3 s), detection range of 10–100 nM, and the extreme detection limit as low as about 3.3 nM. The good stability, repeatability and anti-interference performance further support TCPP(Ni)-Co MOF function as an excellent electrochemical sensor for theophylline. The enhanced detection mechanisms have been carefully discussed with X-ray photoelectron spectroscopy (XPS) and cyclic voltammograms (CVs) experiments. The coordination of Ni2+ in higher electron affinity could construct more electron-deficient environment in the well conjugate TCPP ligand, which could reduce the electron compensation to Co2+ in the formation of Co-COO coordination bond and set “Co-COO” in a higher oxidation state, thus enables TCPP(Ni)-Co MOF as the high-performance sensor for trace theophylline.

Dual-signal optical detection of Lead(II) ions (Pb2+) using galloyl group-functionalized polydiacetylene

In this study, we developed a novel galloyl group-functionalized polydiacetylene (Galloyl-PDA) sensor for colorimetric and fluorescent detection of Pb2+. Among three types of Galloyl-PDA vesicles prepared by changing the ratio of newly synthesized galloyl group-conjugated 10,12-pentacosadiynoic acid (Galloyl-PCDA) and matrix 10,12-tricosadinoic acid (TCDA), the blue Galloyl-PDA vesicles with 1:9 molar ratio of Galloyl-PCDA:TCDA showed the most dramatic color transitions to red with colorimetric response (CR) value of 46.66 ± 1.373% within 5 min upon addition of 50 μM Pb2+. However, they didn't exhibit any color change upon interaction with other heavy metals. Since the terminal galloyl moieties of the Galloyl-PDA vesicles could form coordination bonds with Pb2+, the Galloyl-PDA vesicles were stressed and showed obvious blue-to-red chromatic transitions. Besides, because the Galloyl-PDA vesicles exhibited nonfluorescent-to-fluorescent transitions, a linear response in colorimetric and fluorescent signals was observed in the range of 0–10 μM and 0.025–1 μM, respectively. From the colorimetric and fluorescent results, the limit of detection (LOD) was determined to be 1.329 μM and 0.068 μM, which is 8-fold and 12-fold better sensitivity than those of previously reported methods, respectively. Furthermore, the capability of our PDA sensor for detection of Pb2+ in tap water, river water, and human serum was validated with excellent precision and recovery rates of 97.14–100.0%, 99.05–103.3%, and 100.7–106.7%, respectively. As our PDA dual-signal sensor for Pb2+ is rapid, sensitive, specific, and detectable by the naked eye, this approach holds great promise for application in point-of-care testing (POCT).

Ex situ synthesis of MOF@PET/cotton textile fibers as potential antibacterial materials

There is considerable scientific literature on MOF-based antibacterial textiles, especially with in situ methodologies for their synthesis. On the contrary, the ex situ synthesis of MOFs on fabrics has been little explored. Although, the latter may have more significant advantages when the expectation is to scale up the process industrially. The present study describes the synthesis of ex situ obtained MOF-199 and MOF-UiO-66-NH2 onto carboxylated polyester/cotton (PETco) textile fibers and their preliminary-qualitative analysis as potential antibacterial textiles. For this, free synthesized MOFs were anchored on a previously carboxylated PETco fiber, using conditions that seek the formation of coordination bonds between the carboxyl groups of the fiber and the metal in the MOF. After soxhlet purification with water and methanol for more than 48 h, analysis by FTIR-ATR and XRD shows the superposition of signals typical of the fiber and the MOF, resembling what was previously reported for cotton-MOF systems. XPS showed 4.47% Cu, with Cu–O-C interactions for MOF-199@PETco, and 12.06% Zr, with Zr-O-C interactions for MOF UiO-66-NH2@PETco. Results corroborated by the SEM micrographs, which show the expected morphology for MOF-199, and homogeneously distributed MOF UiO-66-NH2 crystals when they are anchored to the fiber.

Enhancing Performance and Stability of Perovskite Solar Cells through Surface Defect Passivation with Organic Bidentate Lewis Bases.

Organic Lewis bases [2,2′-bipyridine (BPY), 4-hydroxy-1,5-naphthyridine-3-carbonitrile (DQCN), and thenoyltrifluoroacetone (TTFA)] with bi-coordination sites of N and O were employed as perovskite surface defect passivants to address the efficiency and stability issues of perovskite solar cells (PSCs), with typical phenethylammonium iodide (PEAI) and piperazinium iodide (PI) passivants as reference. The surface properties of the perovskite films before and after passivation were characterized by Fourier-transform infrared, ultraviolet–visible, photoluminescence (PL), and time-resolved PL spectroscopy, X-ray diffraction, ultraviolet photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. The characterizations reveal that BPY, DQCN, or TTFA forms coordination bonds with exposed “Pb2+”, leading to a slight decrease in the highest occupied molecular orbital or lowest unoccupied molecular orbital energy level and bandgap. These passivants (especially TTFA) can passivate the perovskite surface defects to inhibit non-radiative recombination while having almost no influence on the grain size and surface morphology. Utilizing the passivated perovskite as the light absorption layer, solar cells with an inverted configuration of indium tin oxide/NiOx/passivated MAPbClxI3–x/C60/BCP/Ag have been fabricated, and power conversion efficiencies of 19.22, 17.85, 16.49, 16.31, and 17.88% have been achieved from PEAI, PI, BPY, DQCN, and TTFA, respectively. All the device performance based on passivated perovskite is superior to that of the control (15.75%) owing to the reduced carrier recombination. The device from TTFA exhibits almost comparable efficiency to that of PEAI and PI controls, indicating that TTFA has an equal excellent passivation effect to state-of-the-art PEAI and PI. Furthermore, the devices based on BPY, DQCN, and TTFA show superior long-term stability with an efficiency loss of only 13.2, 16.7, and 12.9%, respectively, after being stored for 40 days in a ∼12% humidity, low-oxygen level environment, which is 45.4, 38.8, and 44.4% for the control, PEAI, and PI devices, respectively, primarily due to the improved hydrophobicity of the perovskite surface. Our results demonstrate that it is feasible to achieve high-efficiency and long-term-stable perovskite solar cells via selecting the appropriate molecules to passivate perovskite surface defects.

Selective recovery of Cu(II) from strongly acidic wastewater by zinc dimethyldithiocarbamate: Affecting factors, efficiency and mechanism

The selective recovery of copper from strongly acidic wastewater containing mixed metal ions remains a significant challenge. In this study, a novel reagent zinc dimethyldithiocarbamate (Zn(DMDC)2) was developed for the selective removal of Cu(II). The removal efficiency of Cu(II) reached 99.6% after 120 min reaction at 30°C when the mole ratio Zn(DMDC)2/Cu(II) was 1:1. The mechanism investigation indicates that the Cu(DMDC)2 products formed as a result of the displacement of Zn(II) from the added Zn(DMDC)2 by Cu(II) in wastewater, due to the formation of stronger coordination bonds between Cu(II) and the dithiocarbamate groups of Zn(DMDC)2. Subsequently, we put forward an innovative process of resource recovery for strongly acidic wastewater. Firstly, the selective removal of Cu(II) from actual wastewater using Zn(DMDC)2, with a removal efficiency of 99.7%. Secondly, high-value CuO was recovered by calcining the Cu(DMDC)2 at 800°C, with a copper recovery efficiency of 98.3%. Moreover, the residual As(III) and Cd(II) were removed by introducing H2S gas, and the purified acidic wastewater was used to dissolve ZnO for preparation of valuable ZnSO4·H2O. The total economic benefit of resource recovery is estimated to be 11.54 $/m3. Accordingly, this study provides a new route for the resource recovery of the treatment of copper-containing acidic wastewater.

Supramolecular Self‐Assembled Structure of Symmetrical Dicyclopentyl Substituted Cucurbit[6]uril with Calcium and Erbium Ions

AbstractDicyclopentyl substituted cucurbit[6]uril (CyP2Q[6]) is used to construct supramolecular self‐assembly with Ca and Er ions, respectively, and the obtained crystals are characterized by the X‐ray single crystal diffraction technique, with results showing that two Ca2+ form coordination bonds with two CyP2Q[6] carbonyl oxygen atoms and ten water molecules, respectively, while Er3+ first coordinates with eight water molecules and then forms hydrogen bonds through the coordinated water with the portal carbonyl oxygen on the CyP2Q[6], thus forming a 1D supramolecular chain, and a honeycomb‐like framework between two adjacent CyP2Q[6] through [ZnCl4]2–.