Ligand Ion Research Articles

Optical and surface properties of Schiff base ligands and Cu(II) and Co(II) complexes

Objectives. To study the transition of electrons in 1,2-phenyl(4’-carboxy)benzylidene Schiff base ligand and transition metal ions, optical properties, as well as the surface chemistry of supported transition metals using diffuse reflectance spectroscopy (DRS); to study the roughness and morphology of the Schiff base ligand and its complexes using atomic force microscopy (AFM).Methods. DRS, AFM, and Fourier-transform infrared spectroscopy instruments were used to identify electron transitions, optical properties, and surface morphology in Schiff base ligands and their complexes.Results. The DRS revealed the d–d transitions and charge transfer shifts of all compounds, and helped identify the structure of the ligand. One of the optical properties studied was the energy gap calculation of the ligand and its complexes. The copper complex exhibited more semiconducting behavior with surface morphology properties such as surface roughness parameters lower than those of the ligand and the cobalt complex. This can be attributed to the smaller size of the copper atom, as well as lower electron transitions compared to the cobalt complex and the square planar bonding shape.Conclusions. In Schiff base ligands, the reflectance spectrum bands reveal three electron transitions: n→π*, π→π*, and σ→σ* transitions. In cobalt complexes, four transitions are indicated: 4A2(F)→4T1(F), 4A2(F)→4T1(P), charge transfer bands, and tetrahedral geometry. Copper complexes exhibit three transitions: 2B1g→2A1g, 2B1g→2Eg, and charge transfer bands, with a square planar geometry for their structure. The energy gap calculations were 2.42, 2.29, and 2.30 eV, respectively. In the case of the SH ligands, copper complexes, and cobalt complexes, all compounds exhibited semiconductor properties. However, the complexes displayed increased conductivity due to the influence of the metal and coordination structure.

Anion regulation for surface passivation enables ultrahigh-stability perovskite nanocrystals.

All-inorganic perovskite CsPbBr3 nanocrystals (NCs) display high photoluminescence quantum yield and narrow emission, which show great potential application in optoelectronic devices. However, the poor environment stability of NCs will hinder their practical application. Herein, a series of ionic liquids with different anions (BF4-, Br-, and NO3-) were used as a sole capping ligand to synthesize NCs. Among the three samples, 1-hexadecyl-3-methylimidazolium tetrafluoroborate ([C16MIM]BF4) capped NCs have the highest stability in light, thermal, and water, possibly attributing to the in situ passivation of bromine vacancy via pseudohalogen BF4- and tight binding of ionic liquid ligands and lead atoms. In addition, green-emission [C16MIM]BF4 NCs were used to assemble a white light-emitting diode device, and it possessed a wide National Television System Committee color gamut of 124.5% and a stable emission peak at high driving currents of 380 mA. This work paves the way for resurfacing perovskite NCs with ultrahigh stability, thereby driving the perovskite NC display industry closer to real-world application.

A multifunctional Eu-organic framework for fluorescence sensing properties and the detection of pyrimethanil in real samples

Europium metal–organic frameworks (Eu-MOFs) have unique application prospects in the field of fluorescence sensing, due to the fluorescence characteristics of Eu3+ ion and organic ligands, and the advantages of obvious red luminescence, long emission lifetime, large Stokes shift, and high quantum yield. In this study, a novel Eu-MOF was synthesized hydrothermally using europium acetate hexahydrate (Eu(Ac)3·6H2O), 5-(4′-carboxybenzyloxy) isophthalic acid (5-H3CIA), and 4,4′-bipyridine (4,4′-bipy). Structural analysis revealed that the Eu-MOF exhibited a three-dimensional framework with 4,4′-bipyridine as the guest molecule. Fluorescence sensing experiments revealed that 2,4,6-trinitrophenol, ornidazole, pyrimethanil, and Cr2O72− effectively quenched the fluorescence of the Eu-MOF in aqueous solution, with corresponding limits of detection as low as 0.886, 0.732, 0.569, and 2.800 μM, respectively. Exploiting the ability of Cr2O72− to quench the fluorescence of the Eu-MOF, we devised a Cr2O72−@Eu-MOF fluorescence silencing system that, in the presence of ascorbic acid, gradually recovered its fluorescence to form a unique fluorescence “on–off-on” sensor. In addition, the fluorescence sensing mechanism of Eu-MOF was studied, the fluorescence test was prepared to detect Cr2O72− with an open eye, and the content of pyrimethanil was detected in real samples, including cucumber skin, tomato skin, grape skin, apple and kiwi.

Construction of Ion-Imprinted Graphene Oxide Mixed-Matrix Membranes for Selective Adsorption and Separation of Tm3.

Efficient adsorption and separation of rare earth from other similar rare earth wastewater has become an urgent demand for resource utilization of ion-type rare earth minerals in China. Herein, thulium (Tm) ion-imprinted graphene oxide (GO)-doped polyether sulfone (PES) membranes (GO-TII/PES-2 membranes) were prepared, in which ion-imprinted graphene oxide was applied as an efficient Tm3+ ionic ligand in the imprinted layer and polyether sulfone was applied as a carrier in the membrane matrix to achieve the selective adsorption and separation of Tm3+ and neighboring rare earth ions. Combined with an ion rectifier, the separation and purification performances of Tm3+ were explored. The separation factors β(Tm3+/Tb3+), β(Tm3+/Sm3+), β(Tm3+/Nd3+), and β(Tm3+/Ce3+) in the dynamic adsorption process increased significantly from 1.22, 1.04, 1.04, and 1.02 for nonimprinting to 3.07, 3.91, 3.91, and 3.33 for imprinted membranes. The GO-TII/PES-2 membrane adsorbed about three times more Tm3+ than the nonionic-imprinted (GO-NII/PES) membrane by adding a color developer and quantifying Tm3+ based on a fast and easy UV-photometric method. After eight dynamic permeations, the adsorption of Tm3+ by the GO-TII/PES-2 membrane decreased by only 13%, indicating that the membrane has good reuse performance. Additionally, the investigation examined the influence of Tm3+ on wheat seed germination, underscoring its potential application in agriculture and the importance of adsorbing and separating rare earth ions.

Selective separation of light and heavy rare earth elements from acidic mine waters by integration of chelating ion exchange and ligand impregnated resin

This study addresses the potential of sourcing Critical Raw Materials (CRMs) using Acidic Mine Waters (AMWs) as a secondary resource. AMWs, often viewed as waste, contain valuable metals like zinc and copper, as well as critical metals like magnesium and cobalt. Moreover, recent studies also reported the presence of Rare Earth Elements (REEs) at concentrations (mg/L) that make their extraction both technically and economically viable. The research focuses on a circular process to recover these metals from AMWs, specifically from the Aznalcóllar open-pit mine, which contains 216 mg/L of Al, 47 mg/L of Fe, 547 mg/L of Zn, and 18.56 mg/L of REEs. The proposed method involves pre-treating the AMW to remove Fe and Al, achieving removals of over 99.9 % and 90 %, respectively, at pH 4.5. Following this, transition metals like Zn, Cd, and Cu were removed as sulphides with a removal efficiency exceeding 99 %. This pre-treatment step reduced the concentration of competing metals in the ion-exchange process, thereby enhancing the recovery and purity of REEs. To separate heavy and light REEs, two types of resins in series were used: an impregnated resin (TP272) and a chelating resin (S930), which can be regenerated using sulphuric acid (H2SO4). The final recovery of REEs as oxalates was achieved using oxalic acid and ammonia at pH 1, with further optimization of the elution process to minimize ammonia consumption and undesired precipitation of other oxalates. Finally, REE oxalates with purities exceeding 90 % were obtained. This research demonstrates a sustainable method for efficiently recovering valuable REEs from AMWs, while also addressing environmental concerns related to hazardous sludge generation.

TBAPy-based metal-organic frameworks with phosphate-induced fluorescence for detecting gossypol

How to achieve good dispersion of MOFs (metal–organic frameworks) is the key to its application in many fields. In our work, a novel MOF nanocomposite TBAPy-Yb was synthesized by solvothermal approach with TBAPy [1,3,6,8-tetrakis(p-benzoic acid)pyrene)] as the organic ligand and lanthanide metal ions as the metal ion source. Due to the coordination between phosphate and TBAPy-Yb, TBAPy-Yb had excellent dispersion in phosphate buffer and induced strong fluorescence emission in 435 nm. Gsp (gossypol) could regularly and instantly quench the induced fluorescence of TBAPy-Yb in the range of 10.0 to 70.0 μM and cause an obvious color change from blue to colorless. The detection limit was as low as 4.57 μM. The possible interferences in cottonseed oil did not influence the detection. The proposed method was effectively applied toanalyzeGsp oil with a recovery rate ranging from 94.20 % to 104.90 %. Furthermore, a portable and smart sensing platform was developed based on probe fixation and mobile phones.

Chelerythrine inhibits NR2B NMDA receptor independent of PKC activity

N-methyl-D-aspartate receptors (NMDAR), the ligand ion glutamate receptor channels, mediate major excitatory neurotransmission in central nervous system (CNS). They highly express in CNS and involve in multiple physiological processes. Many studies implicated that NMDAR plays a crucial role in number of neurological disorders, including ischemia, dementia, and pain, indicating its potential as a therapeutic target for treatments. Chelerythrine (CHE) is a benzo-phenanthridine alkaloid extracted from Chelidonium majus with many biological activities including anti-inflammatory, anticancer effect, and antidiabetic effect. But the mechanism of CHE is not well understood. The aim of this study was to investigate the effect of CHE on the NMDAR. The results demonstrated that CHE effectively suppressed NMDA-induced currents in primary cultured cortical neurons. To elucidate the underlying mechanism, we expressed NMDARs in HEK293 cells and found that CHE and some of its structural analogues inhibited NMDAR currents and facilitated the desensitization of GluN2B NMDARs. Notably, these effects were independent of protein kinase C activity, suggesting that the effect of CHE on GluN2B-containing NMDAR may occur through a mechanism of directly interaction with NMDAR. Moreover, the inhibitory effect of CHE on GluN2B NMDARs is pH-dependent. Molecular docking prediction in conjunction with mutagenesis analysis revealed that the M3 α-helical segment of the NMDAR in close proximity to the GluN2B Thr647 amino acid plays an important role in CHE inhibition of GluN2B. This study revealed a novel function of CHE and its structural analogues in inhibiting the NMDARs and promoting GluN2B-mediated desensitization by obstructing the receptor at the channel pore region.

Structural insights into the human P2X1 receptor and ligand interactions.

The P2X1 receptor is a trimeric ligand-gated ion channel that plays an important role in urogenital and immune functions, offering the potential for new drug treatments. However, progress in this area has been hindered by limited structural information and a lack of well-characterised tool compounds. In this study, we employ cryogenic electron microscopy (cryo-EM) to elucidate the structures of the P2X1 receptor in an ATP-bound desensitised state and an NF449-bound closed state. NF449, a potent P2X1 receptor antagonist, engages the receptor distinctively, while ATP, the endogenous ligand, binds in a manner consistent with other P2X receptors. To explore the molecular basis of receptor inhibition, activation, and ligand interactions, key residues involved in ligand and metal ion binding were mutated. Radioligand binding assays with [3H]-α,β-methylene ATP and intracellular calcium ion influx assays were used to evaluate the effects of these mutations. These experiments validate key ligand-receptor interactions and identify conserved and non-conserved residues critical for ligand binding or receptor modulation. This research expands our understanding of the P2X1 receptor structure at a molecular level and opens new avenues for in silico drug design targeting the P2X1 receptor.

Resistive random access memory based on organic-metallic hybrid polymer

Abstract Resistive random access memories (ReRAMs) based on an organic-metallic hybrid polymer, Poly(Fe-btpyb) Purple, were fabricated. This material was synthesized by complexation of metal ion and organic ligand. When applying forward bias, an abrupt resistance change from a low resistance state (LRS) to a high resistance state (HRS), which is known as reset process, was observed. In contrast, a reverse bias switched the resistance from HRS to LRS (set process). The resistive switching phenomenon is probably caused by the electrochemical oxidation-reduction reaction of the metal ion (Fe(II)/Fe(III)). The nonvolatile memory characteristics were measured with data-retention tests, showing no significant degradation over 105 s. The endurance characteristics exhibited sufficient long-term durability, due to no conformational change of the organic ligand. It is proposed that the difference in charge-transfer efficiency between the reduced state (Fe(II)) and oxidized state (Fe(III)) might be the physical mechanism of the resistive switching.

The Role of Carrier Ion‐Ligand Interaction on Intercalation Potentials and Phase Evolution of Berlin Green Cathodes in Rechargeable Batteries

AbstractIntercalation and deintercalation are fundamental processes in battery electrodes that involve the reversible addition and extraction of carrier ions such as lithium (Li) and sodium (Na) into a host framework made of transition metal (TM) ions and ligands. Although TM–ligand interactions are known to primarily determine intercalation potentials, a comprehensive understanding of their interactions involving the carrier ions still remains elusive. This study investigates the complex interactions between carrier ions (Li and Na) and the ligand in Berlin green (BG, Fe3+[Fe3+(CN)6]) cathodes to elucidate their effects on intercalation potentials and phase evolution. Comprehensive X‐ray characterizations and electrochemical analyses reveal that the strong carrier ion–ligand interaction, influenced by the type and concentration of carrier ions, can modify the electronic structure of Fe ions and affect the intercalated structure of BG cathodes, thereby tuning the intercalation potentials. Specifically, the enhanced covalent interaction of the Na–CN units compared with that of the Li–CN units induces rhombohedral distortion in the fully sodiated state and increases the working potential of high‐spin Fe ions. The findings highlight the critical role of carrier ion–ligand interactions in tuning the electrochemical properties of battery electrodes for the design of advanced battery systems.

Benchtop-Stable Carbyl Iminopyridyl NiII Complexes for Olefin Polymerization.

Design of catalysts for Ni-catalyzed olefin polymerization predominantly focuses on ligand design rather than the activation process when attempting to achieve a broader scope of polyolefin micro- and macrostructures. Air-stable alkyl-or aryl-functionalized NiII precatalysts were designed which eliminate the need of in situ alkylating processes and are activated solely by halide abstraction to generate the cationic complex for olefin polymerization. These complexes represent an emerging class of olefin polymerization catalysts, enabling the study of various cocatalysts forming either inner- or outer-sphere ion pairs. It is demonstrated that an organoboron cocatalyst activation produces a well-defined ion pair, which in contrast to ill-defined organoaluminum cocatalysts, can directly activate the complex by halide abstraction to yield comparatively higher molecular weight homo/copolymers. Under high ethylene pressure, broader branching densities and the gradual incorporation of short-chain branches were achieved, circumventing the need for elaborate ligand design and copolymerization with α-olefins. The underlying chain-walking mechanism and ion pair interactions were further elucidated by DFT calculations. A phenyl group on the bridging carbon functioned as a rotational barrier, producing higher molecular weight polymers compared to methyl-substituted analogs. Here, we provide a perspective to manipulate the iminopyridyl NiII system, leveraging ion pair interactions and ligand design to govern polyolefin molecular weights and microstructures.

N, N’-bidentate ligand anchored palladium catalysts on MOFs for efficient Heck reaction

Metal-organic frameworks (MOFs), recognized as advanced catalyst carriers due to their adjustable porous, diverse structure and highly exposed active sites, have earned increasing attention for their potential to address the longevity of catalytic centers. In this manuscript, we have devised and synthesized a multifunctional amino-pyridine benzoic acid (APBA) ligand to replace the modulator ligand of the MOF-808 and disperse the palladium catalytic centers atomically on the MOF-APBA. The resulting single-site catalytic system, Pd@MOF-APBA, demonstrates preeminent efficiency and stability, as evidenced by a high average turnover number (95000) and a low metal residue (4.8 ppm) in the Heck reaction. This catalyst has exhibited recyclability for multiple runs without significant loss of reactivity for gram-scale reactions. The catalyst’s high activity and efficiency can be attributed to the suitable electrical properties and structures of the N, N’-bidentate ligand for the catalytic palladium ions, postponing their deactivations, including leaching and agglomeration.

A Theoretical Study on the Influence of Five- and Six-Membered N-Heterocyclic Ring Side Chains of the N-Donor Extractants on Am(III)/Eu(III) Extraction and Separation.

According to the green development requirements of carbon neutrality and carbon peaking, the effective separation of lanthanides and actinides is one of the key factors for nuclear energy to become a sustainable energy source. In recent years, o-phenanthroline-based ligands have been proven to be effective in the separation of lanthanides and actinides. In this work, based on 5,9b-dihydro-4aH-cyclopenta[1,2-b:5,4-b']dipyridines, we designed six N-heterocyclic ring ligands and theoretically studied their extraction capacity and separation selectivity for the Am(III) and Eu(III) ions. Various theoretical methods were used to analyze the properties of the ligands and study the bonding nature of the ligands with the metal ions. Thermodynamic parameters were calculated to measure the extraction ability of the ligands to the metal ions and to explore the separation capacity of the ligand for the Am(III) and Eu(III) ions. The calculated results show that the five- and six-membered N-heterocyclic ring side chains of the ligands and the distribution of the N atoms on the side chain rings have obvious effects on the bonding of the ligands to metal ions and on the extraction and separation properties of the ligands for the metal ions. It was found that the extractants with six-membered ring side chains possess an extraction ability slightly better than that of the ligands with five-membered ring side chains and that the ligands with a pair of adjacent N atoms on the side chains have a stronger separation selectivity for the Am(III)/Eu(III) ions. The theoretical research in this work will help to understand the details of binding and extraction properties of similar ligands and provide insights for the future design of five- and six-membered heterocyclic ligands.

Low-potential anodic electrochemiluminescence of terbium metal-organic frameworks for selective microRNA-155 detection

High excitation potential is recognized as a harmful factor for the biological activity of biomacromolecules, such as proteins and nucleic acids, in electrochemiluminescence (ECL) biosensing. Developing low-potential ECL luminophores is vital for improving ECL accuracy in actual sample sensing. In this work, based on porous metal-organic framework (MOF) structure with multiple active sites and energy transfer between the excited ligands and Ln nodes, we designed a series of Ln-MOFs and observed ECL emission at low potential, providing a novel method to realize low-potential ECL. The MOF nanoemitters were prepared using 1,3,5-tri (4-carboxyphenyl)benzene ligand and several lanthanide ions as nodes through mild hydrothermal reaction. Interestingly, strong ECL emission at +0.75 V of peak potential was observed in the ECL-potential curve of Tb-based MOF using 2,2′,2″-nitrilotriethanol as coreactant, which was beneficial for reducing background interference in biosensing, and this ECL emission was attributed to the energy transfer between Tb and excited ligand. This low-potential ECL was then applied to construct an ECL biosensor with newly developed Cas12a-based method for selective detection of microRNA-155 without the help of strand displacement or reverse transcription. For this ECL system, the limit of detection was 0.78 nM, and the overall detection time was 2.5 h. The Ln-MOF nanoemitter provides a robust ECL platform to selectively detect various targets by integrating new bio-related techniques.

Synchronized crystallization in tin-lead perovskite solar cells

Tin-lead halide perovskites with a bandgap near 1.2 electron-volt hold great promise for thin-film photovoltaics. However, the film quality of solution-processed Sn-Pb perovskites is compromised by the asynchronous crystallization behavior between Sn and Pb components, where the crystallization of Sn-based perovskites tends to occur faster than that of Pb. Here we show that the rapid crystallization of Sn is rooted in its stereochemically active lone pair, which impedes coordination between the metal ion and Lewis base ligands in the perovskite precursor. From this perspective, we introduce a noncovalent binding agent targeting the open metal site of coordinatively unsaturated Sn(II) solvates, thereby synchronizing crystallization kinetics and homogenizing Sn-Pb alloying. The resultant single-junction Sn-Pb perovskite solar cells achieve a certified power conversion efficiency of 24.13 per cent. The encapsulated device retains 90 per cent of the initial efficiency after 795 h of maximum power point operation under simulated one-sun illumination.

Nutrient removal in floating and vertical flow constructed wetlands using aluminium dross: An innovative approach to mitigate eutrophication

On global scale, eutrophication is one of the most prevalent environmental threats to water quality, primarily caused by elevated concentration of nutrients in wastewater. This study utilizes aluminum dross (AD), an industrial waste, to create a value-added material by improving its operational feasibility and application for removing phosphate and ammonium from water. The operational challenges of AD such as its powdered nature and effective operation under only extreme pH conditions were addressed by immobilizing in calcium alginate to form calcium alginate aluminium dross (Ca-Alg-Al dross) beads. These Ca-Alg-Al dross beads were further tested for phosphate and ammonium removal from natural wastewater in two different aqueous environment systems: (i) vertical flow constructed wetlands (VF-CWs) followed by Ca-Alg-Al dross beads fixed bed system and (ii) Ca-Alg-Al dross beads mounted floating constructed wetlands (FCW) for remediating polluted lentic ecosystems. Our results show maximum phosphate and ammonium removal of 85 ± 0.41 % and 93.44 %, respectively, in VF-CWs followed by Ca-Alg-Al dross beads fixed bed system. The Ca-Alg-Al dross beads mounted FCW system achieved maximum phosphate removal of 79.18 ± 8.56 % and ammonium removal of 65.45 ± 21.04 %. Furthermore, the treated water from the FCW system was assessed for its potential to inhibit algal growth by artificially inoculating treated water with natural algae to simulate eutrophic conditions. Interestingly, treated water from the FCW system was found capable of arresting the algal growth. Besides, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Fourier transform infrared (FTIR) spectroscopy confirmed the functional groups and surface properties and probable participation of multiple mechanisms including ion exchange, electrostatic attraction, and ligand complexation for phosphate and ammonium removal. Overall, these results offer a promising way to utilize AD for high-end applications in wastewater treatment.

Design and Production of Functionalized Electrospun Fibers for Palladium Recovery.

Adsorption stands out as a leading wastewater treatment method for ion removal or recovery. Polymeric fibers, notably electrospun ones, are gaining prominence due to their high capacity and easy recovery. Electrospinning offers a cost-effective means to produce fibers with a large surface area and high adsorption capacity. These fibers can be further functionalized with chemical substances acting as specific ligands for metal ions, bolstering their adsorption capabilities. In this study, dithioester-functionalized electrospun fibers were synthesized as an alternative to conventional sorbents for palladium recovery from acidic chloride solutions, similar to those used in hydrometallurgical processes for platinum group metal recovery (Pd, Pt, Rh···) from spent catalysts. Fibers with identical chemical composition but varying morphology were examined to assess their impact on palladium adsorption efficiency (i.e., beads-free and beads-on-string morphologies). Experimental investigations involved model solutions with varying palladium concentration, temperature, acidity (adjusted with HCl content), and salinity (adjusted with NaCl), utilizing both pure and dithioester-functionalized fibers. Experimental results demonstrate enhanced adsorption efficiency at lower temperatures and in 0.1 M HCl, with a negligible influence from solution salinity. Moreover, both pure polymeric and dithioester-functionalized electrospun fibers exhibit highly efficient palladium recovery. Furthermore, under optimal conditions, starting from an 80 mg/L palladium solution, a 95% recovery of palladium can be achieved with a sorbent dosage below 4 g/L of functionalized electrospun fibers. The adsorption data are well described by the Langmuir isotherm model for the pure polymeric fibers. At the same time, the contribution of dithioesters has been separately accounted for to describe the behavior of functionalized electrospun fibers. Thermal recovery of palladium from the spent sorbents has also been investigated.

New nano-complexes targeting protein 3S7S in breast cancer and protein 4OO6 in liver cancer investigated in cell line

Cancer, a lethal ailment, possesses a multitude of therapeutic alternatives to combat its presence, metal complexes have emerged as significant classes of medicinal compounds, exhibiting considerable biological efficacy, especially as anticancer agents. The utilization of cis-platin in the treatment of various cancer types, including breast cancer, has served as inspiration to devise novel nanostructured metal complexes for breast cancer therapy. Notably, homo- and hetero-octahedral bimetallic complexes of an innovative multifunctional ether ligand (comprising Mn(II), Ni(II), Cu(II), Zn(II), Hg(II), and Ag(I) ions) have been synthesized. To ascertain their structural characteristics, elemental and spectral analyses, encompassing IR, UV–Vis, 1H-NMR, mass and electron spin resonance (ESR) spectra, magnetic moments, molar conductance, thermal analysis, and electron microscopy, were employed. The molar conductance of these complexes in DMF demonstrated a non-electrolytic nature. Nanostructured forms of the complexes were identified through electron microscopic data. At ambient temperature, the ESR spectra of the solid complexes exhibited anisotropic and isotropic variants, indicative of covalent bonding. The ligand and several of its metal complexes were subjected to cytotoxicity testing against breast cancer protein 3S7S and liver cancer protein 4OO6, with the Ag(I) complex (7) evincing the most potent effect, followed by the Cu(II) with ligand (complex (2)), Cis-platin, the ligand itself, and the Cu(II)/Zn(II) complex (8). Molecular docking data unveiled the inhibitory order of several complexes.

Electroless Copper Plating on a Cotton Surface: Effect of Metal Ion Ligand Stability Constant on Reduction Deposition.

Electroless plating facilitates the metallization of nonconductive substrate surfaces, and of note, the precise control of the bath stability constant influences the deposition process of metal particles. In this paper, trisodium citrate, potassium sodium tartrate, nitrogen triacetic acid, thiourea, and ethylenediamine tetraacetic acid disodium were selected as coordination agents, and the effect of the metal ion ligand stability constant on the reduction deposition was studied. Coordination bonds can be established between the Cu2+ and O/N/S particles in the ligand because paired electrons in O/N/S hybrid orbitals tend to occupy empty Cu2+ hybrid orbitals and establish coordination bonds. More importantly, the copper-potassium sodium tartrate ligand exhibits the lowest stability constant and lowest reduction barrier. As an exception, a consecutive Cu-plated coating with an excellent crystallinity property was deposited on the cotton surface when potassium sodium tartrate was used as the coordination agent in the plating solution. The deposition amounts are 55.2% and 74.1% after 1 and 4 h of electroless copper plating, respectively. The surface resistivity of Cu-plated cotton is 0.38 Ω/cm2, and additionally, the surface resistivity ratio before and after 1000 cycles fluctuated between 0.9 and 1.1, indicating that the Cu-plated cotton exhibits outstanding flexibility. In this paper, the deposition rate can be optimized by adjusting the copper particle ligand stability constant in the plating solution, aiming to achieve optimal results.

Effect of Lanthanide Ions and Triazole Ligands on the Molecular Properties, Spectroscopy and Pharmacological Activity.

The effect of La, Ce, Pr and Nd ions on four Ln(ligand)3 complexes and at three DFT levels of calculation was analyzed. Four ligands were chosen, three of which were based on the 1,2,3-triazole ring. The DFT methods used were B3LYP, CAM-B3LYP and M06-2X. The relationships established were between the geometric parameters, atomic charges, HOMO-LUMO energies and other molecular properties. These comparisons and trends will facilitate the synthesis of new complexes by selecting the ligand and lanthanide ion best suited to the desired property of the complex. The experimental IR and Raman spectra of Ln(2b')3 complexes where Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er ions have been recorded and compared to know the effect of the lanthanide ion on the complex. The hydration in these complexes was also analyzed. Additionally, the effect of the type of coordination center on the ability of an Ln(ligand)3 complex to participate in electron exchange and hydrogen transfer was investigated using two in vitro model systems-DPPH and ABTS.