Cl Complexes Research Articles

A chlorine isotope transect across Sudbury Basin (Canada) impact deposits reveals systematic isotope fractionation

Large-scale impacts are known to have a significant effect on volatile systematics (e.g., hydrogen and chlorine) owing to syn- and post-shock pressures and temperatures allowing for ready volatile loss and isotopic fractionation. We determined the Cl isotopic composition and [Cl] and [H2O] for apatite from 10 samples of the Sudbury impact structure in Canada. The high [Cl] and invariant δ37Cl values in the lower norite are attributed to footwall assimilation in agreement with recent Zn and Pb data. The granophyre, the top of the Sudbury Igneous Complex, displays loss and fractionation of Cl (up to +6.26‰) indicative of degassing under a high gas pressure regime with high [H2O] further buffering isotope fractionation. Similar impacts on dry, airless bodies such as the Moon may have permitted greater amounts of isotopic fractionation, supporting extremely fractionated lunar materials as evidence for the large-scale impact-derived degassing hypothesis. The modest fractionation (up to +8.15‰) and morphologically distinct apatite of the Onaping Formation can be explained by post-impact hydrothermal alteration.

Theoretical investigation on the surrounding effects of second-order nonlinear properties for (N^C^N)Pt(II)Cl complexes

Pt(II) complexes are widely used as nonlinear optical (NLO) materials. The geometric and electronic structures, second-order NLO property and UV–Vis absorption spectra of (N^C^N)Pt(II)Cl complexes (1–4) N^C^N binding by central benzene and two lateral N-heterocycles) are evaluated by density functional theory (DFT) and time-dependent DFT calculations. The detailed environmental effect of total first hyperpolarizability (βtot) in the solution and crystal phases is simulated by polarized continuum model (PCM) and quantum mechanics/molecular mechanics (QM/MM) method, respectively. The results highlight that the complex 3 exhibits largest βtot value in the gas, solution and crystal phases which can be attributed to the higher electron π-delocalization of ligands. Further, an evident red shift towards longer wavelength is observed for the complex 3. The origin of larger βtot value can be reasonably interpreted by the two-level model. In addition, the surrounding exerts an important influence on modulating second-order NLO properties. The solvent effect results in the larger βtot value than that of gas phase. The intermolecular interaction plays an important role in crystal phase. The formation of dimer can reduce the βtot value in comparison with the βtot value of the monomer in the crystal phase, because the centrosymmetric configuration of dimer implies a decrease of dipole moment (μ) in contrast to the large μ value of monomer. It is expected that this work will provide some guidance for designing Pt(II) NLO materials.

Two New Inner-sphere Pt(II) Thiosemicarbazone Schiff Base Complexes Immobilized into Magnetic Nanoparticles: Synthesis, Characterization, and Biological Investigations

This study explores the synthesis, characterization, and biological investigations of two new Pt(II) thiosemicarbazone complexes immobilized in magnetic nanoparticles (MNPs). MNPs exhibit distinctive physical and chemical properties that enhance their interactions with biological targets. These traits make them particularly useful, especially when combined with drugs, increasing therapeutic effectiveness while also serving as efficient diagnostic tools in imaging techniques. The two Pt(II) complexes are represented by the formulas [Pt(HL1)(H2O)]Cl and [Pt(HL2)(H2O)2]Cl. The ligand, H2L1 signifies (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazine-1-carbothioamide, while H2L2 stands for (Z)-N-ethyl-2-(2-oxoindolin-3-ylidene)hydrazine-1-carbothioamide. The ligands and their Pt(II) complexes were characterized through various techniques, including elemental analysis, mass spectrometry, thermal analysis, powder X-ray diffraction (XRD), FT-IR, NMR, and UV–visible spectroscopy. The two complexes form a square planar geometry, in which H2L1 performs as a mononegative tridentate while H2L2 acts as a mononegative bidentate. Density Functional Theory (DFT) calculations were utilized to investigate the molecular configurations of the ligands and its Pt(II) complexes. The UV–visible and fluorescence spectroscopy techniques were employed to examine the interactions between Pt(II) complexes and Bovine Serum Albumin (BSA). DNA fragmentation studies on the Pt(II) complexes were performed and showed that [Pt(HL2)(H2O)2].Cl complex is the strongest degraded on the DNA. [Pt(HL1)(H2O)]Cl and [Pt(HL2)(H2O)2]Cl complexes were immobilized into MNPs to produce Pt(L1)/MNPs and Pt(L2)/MNPs, respectively. Pt(L1)/MNPs and Pt(L2)/MNPs were identified using FT-IR, PXRD, SEM, TEM, EDX, and UV-spectroscopy. In vitro cytotoxicity tests on these compounds against MCF-7 cell line is applied. Additionally, the antimicrobial activity against two gram + ve bacteria (Bacillus subtilis and staphylococcus aureus), and two gram −ve bacterial strains (Escherichia coli and Salmonella typhi) was investigated. Furthermore, the antioxidant properties (DPPH) of the investigated compounds were assessed. The results of the study indicated that the [Pt(HL2)(H2O)2].Cl complex exhibited a higher biological potency compared to both the [Pt(HL1)(H2O)2].Cl complex and their respective ligands. When Pt(II) complexes were incorporated into the MNPs, a significant increase in their biological activity was noted, especially for Pt(L2)/MNPs, which exhibited the strongest antibacterial and anticancer effects.

Air-stable palladium N[sbnd]Heterocyclic carbene based CCC[sbnd]NHC pincer complexes: Synthesis, characterization, photophysical and Raman vibrational studies, and DFT studies, plus observation of an abnormal carbene pincer

A series of CCCNHC pincer Pd(II)X complexes, where X = Cl, Br, or I, were synthesized by a metalation/transmetalation reaction sequence and characterized by NMR and Raman spectroscopy, photophysical studies, X-ray crystallography, and DFT computational studies. This is the first detailed report of the CCCNHC pincer Pd complexes analogous to the previously reported Pt analogs. Photophysical measurements show that by varying the X ligand, the emission wavelength can be tuned. The chloride complex is a water and air stable blue emitter with a quantum yield of 46 % and all three complexes have photostabilities >90 %. A combined DFT and TD-DFT study has been carried out to investigate ground state and excited state geometries as well as absorption and emission processes of CCCNHC Pd complexes. Theoretical results were compared with the corresponding experimental results and showed good agreement. Raman spectroscopy (computational and experimental) was used to examine Pd-X vibrations which have been rarely reported in the literature. Several by-products of the metalation/transmetalation procedure were identified. A rare mixed normal/abnormal carbene pincer Pd(II)Cl complex was isolated and crystallographically characterized.

Synthesis and characterization of a zinc-triazole coordination complex with potent antimicrobial and anticancer properties

The synthesis, characterization, and biological appraisement of a novel coordination compound [Zn(C4N4H5O)2(H2O)2]Cl have been comprehensively studied. The compound was synthesized using N-(1H-1,2,4-triazol-3-yl) acetamide and ZnCl2·6H2O, yielding a product characterized by FT-IR, elemental analysis, thermogravimetric analysis (TGA), and single crystal X-ray diffraction. FT-IR spectra confirmed the successful coordination of the ligand to the zinc ion, with significant shifts in characteristic absorption bands such as CO (1685 cm⁻¹), CN (1624 cm⁻¹), and NH (3394 cm⁻¹). Single crystal X-ray diffraction analyses revealed that the complex crystallized in the monoclinic system with space group P21/c and forms six-membered chelate rings. The unit cell parameters were a = 6.0595(3) Å, b = 14.2956(7) Å, c = 9.4762(4) Å, and β = 93.275(4)°. Thermal analysis showed that the complex undergoes stepwise decomposition with significant mass losses at various temperature intervals, including an overall mass loss of 71.09 % between 200 °C and 885 °C. Molecular docking studies indicated strong interactions between the [Zn(C4N4H5O)2(H2O)2]Cl complex and the 6QF6 cancer-related protein antigen A4, with low binding energy values (-9.32 to -8.44 kcal/mol) suggesting high binding affinity and potential biological activity. In vitro antimicrobial screening against several pathogenic microorganisms, viz. both gram-positive and gram-negative bacteria, demonstrated that the [Zn(C4N4H5O)2(H2O)2]Cl complex exhibited superior antibacterial activity, with inhibition zone diameters of 15.3 ± 0.47 mm for Bacillus subtilis and 24.17±0.56 mm for Agrobacterium tumefaciens, compared to N-(1H-1,2,4-triazol-3-yl) acetamide alone and some standard antibiotics. These findings highlight the [Zn(C4N4H5O)2(H2O)2]Cl complex as a promising candidate for developing new antimicrobial and anticancer agents, providing a foundation for further research and potential therapeutic applications.

The Conductance and Thermopower Behavior of Pendent Trans-Coordinated Palladium(II) Complexes in Single-Molecule Junctions.

The present work provides insight into the effect of connectivity within isomeric 1,2-bis(2-pyridylethynyl)benzene (bpb) palladium complexes on their electron transmission properties within gold|single-molecule|gold junctions. The ligands 2,2'-((4,5-bis(hexyloxy)-1,2-phenylene)bis(ethyne-2,1-diyl))bis(4-(methylthio)pyridine) (Lm ) and 6,6'-((4,5-bis(hexyloxy)-1,2-phenylene)bis(ethyne-2,1-diyl))bis(3-(methylthio)pyridine) (Lp ) were synthesized and coordinated with PdCl2 to give the trans-Pd(Lmorp )Cl2 complexes. X-ray photoelectron spectroscopy (XPS) measurements shed light on the contacting modes of the molecules in the junctions. A combination of scanning tunneling microscopy-break junction (STM-BJ) measurements and density functional theory (DFT) calculations demonstrate that the typical lower conductance of meta- compared with para-connected isomers in a molecular junction was suppressed upon metal coordination. Simultaneously there was a modest increase in both conductance and Seebeck coefficient due to the contraction of the HOMO-LUMO gap upon metal coordination. It is shown that the low Seebeck coefficient is primarily a consequence of how the resonances shift relative to the Fermi energy.

Enhanced Thermally Activated Delayed Fluorescence by Sole Coordination: From an Organic Molecule to Its Zinc Complex.

A BPAPTPyC organic molecule containing a sandwich structural chromophore is designed and synthesized to produce blue thermally activated delayed fluorescence (TADF). The chromophore is composed of two di(4-tert-butylphenyl)amino donors and one inserted terpyridyl acceptor hitched at positions 1, 8, and 9 of a single carbazole via the p-phenylene group, in which the multiple space π-π interactions between the donor and acceptor enable the molecule to possess the TADF feature with a high energy emission at 470 nm but a low photoluminescence quantum yield (PLQY) and a small proportion of the delayed component. In contrast, the corresponding Zn(BPAPTPyC)Cl2 complex has a high PLQY and a short lifetime with a red-shifted emission due to the enhanced rigidity and electron accepting ability of the terpyridyl group from coordination. A solution-processed organic light-emitting diode (OLED) based on the complex achieves a maximum external quantum efficiency (EQE) of 17.9% with an emission peak at 585 nm, while an OLED of the organic molecule produces blue emission with a maximum EQE of 2.7%.

The Effect of Selenium-Based Ligands on Tungsten Acetylene Complexes.

Bioinspired tungsten acetylene complexes containing pyridine-2-selenolato (PySe) or 6-methyl-pyridine-2-selenolato (6-MePySe) ligands were synthesized. 77Se NMR spectroscopy allowed for an assessment of the resonance structures in the pyridine-2-selenolato ligands and the rationalization of chemoselectivity observed in regard to 1,2 migratory insertion of HC≡CH. [W(CO)(C2H2)(CHCH-PySe)(PySe)] is formed exclusively via insertion of HC≡CH into the W-N bond, while the use of bulkier 6-MePySe allows for the isolation of [W(CO)(C2H2)(6-MePySe)2], which only partially reacts with excess HC≡CH to give [W(CO)(C2H2)(CHCH-6-MePySe)(6-MePySe)]. Oxidation of [W(CO)(C2H2)(6-MePySe)2] with pyridine-N-oxide gave the tungsten(IV) complex [WO(C2H2)(6-MePySe)2]. Complexes [W(CO)(C2H2)(6-MePySe)2] and [WO(C2H2)(6-MePySe)2] react with trimethyl phosphine to carbyne complex [W(CO)(CCH2PMe3)(PMe3)2(6-MePySe)]Cl and alkylidene complex [WO(CHCHPMe3)(PMe3)2(6-MePySe)]Cl, respectively. The addition of substituted alkynes to [W(CO)3(PySe)2] via thermal decarbonylation gave complexes [W(CO)(MeC≡CMe)(PySe)2] and [W(CO)(HC≡Ct-Bu)(PySe)2], respectively. The here presented complexes are relevant for the modeling of the active site of acetylene hydratase from Pelobacter acetylenicus, in which a tungsten atom is enclosed in a sulfur-rich coordination sphere. A recently published theoretical study concluded that the exchange of sulfur for selenium would increase the activity of the enzyme. Our findings contrast this claim as comparative analysis concludes negligible structural and electronic differences between the selenium-based and previously published sulfur-based complexes.

Computational Assessment of the Mechanistic Journey in Chan-Lam-Based Arylation of Imidazoles.

Cu(II)-catalyzed C-N bond formation reactions remain one of most widely practiced and powerful protocols for the synthesis of value-added chemicals, bioactive molecules, and materials. Despite numerous experimental contributions, the overall mechanistic understanding of the C-N coupling reaction based on the Chan-Lam (CL) reaction methodology is still limited and underdeveloped, particularly with respect to the use of different substrates and catalytic species. Herein, we report an in-depth DFT-based study on the mechanism of N-arylation of imidazoles following Collman's experimental setup. Our findings unfold for the first time the ligand-based CL coupling catalyzed by the [Cu(II)(OH)TMEDA]2Cl2 complex. The transmetalation step with an energy span of 26.2 kcal mol-1 is rate-determining, while the subsequent disproportionation and reductive elimination are relatively facile (δE = 16.4 kcal mol-1) in comparison to the CL amination of secondary amines. The final oxidative catalyst regeneration results in the presence of O2, accompanying an energy span of 12.8 kcal mol-1, where hydrogen transfer from the coordinated water allows the reduction of superoxo linkage. Couplings performed in the presence of a combination of bidentate sp3-N ligands with single and double -(CH2)- spacer units afford a kinetically facile transformation (24.5 kcal mol-1). Furthermore, our results agree with the experimental outcomes of regioselective couplings of substituted imidazoles.

Manganese‐Catalyzed α‐Alkylation of Sulfones using Alcohols via a Hydrogen‐Borrowing Strategy: Synthesis of Branched Sulfones

AbstractHerein, we report an efficient and sustainable manganese‐catalyzed α‐C−H bond alkylation methodology to synthesize branched sulfones via a hydrogen borrowing pathway. The air‐stable and phosphine‐free Mn‐catalyst, (NNN)Mn(II)Cl2 was synthesized by using an earth‐abundant, commercially available, and inexpensive precursor MnCl2.4H2O, and a stable NNN pincer i. e. [N‐((benzimidazole‐2‐yl)methyl)quinoline‐8‐amine] ligand system. Taking benzyl phenyl sulfones as substrates, and benzyl alcohol derivatives as alkylating agents, a range of branched sulfones were synthesized in 40–82 % isolated yields using (NNN)Mn(II)Cl2 complex as the catalyst under open‐air conditions. Control experiments and deuterium incorporation studies have also been conducted to investigate the possible reaction mechanism and to provide evidence for the hydrogen borrowing pathway.

Design and Synthesis of C₄-Symmetric Axially Chiral β-Aryl Porphyrins and Application for Supporting Ir(III)-Catalyzed Enantioselective C-H Alkylation.

A hitherto unknown class of C4-symmetric Caryl-Cβ (C3, C8, C13, C18) axially chiral porphyrins has been synthesized and the application of their iridium (Ir) complexes in catalytic asymmetric C(sp3)-H functionalization is documented. Cyclotetramerization of enantioenriched axially chiral 2-hydroxymethyl-3-naphthyl pyrroles under mild acidic conditions affords, after oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), the C4-symmetric α,α,α,α-atropenantiomer as an only isolable diastereomer. Both regioisomeric Ir(Por*)(CO)(Cl) complexes catalyze the carbene C-H insertion reaction affording the same enantiomer, albeit with slight difference in enantioselectivity. With the optimum Ir-complex 3e, the 2-substituted arylacetic acid derivatives were generated from diazo compounds and cyclohexadiene in excellent yields and enantioselectivities.

Design and Synthesis of C4‐Symmetric Axially Chiral β‐Aryl Porphyrins and Application for Supporting Ir(III)‐Catalyzed Enantioselective C−H Alkylation

AbstractA hitherto unknown class of C4‐symmetric Caryl−Cβ (C3, C8, C13, C18) axially chiral porphyrins has been synthesized and the application of their iridium (Ir) complexes in catalytic asymmetric C(sp3)−H functionalization is documented. Cyclotetramerization of enantioenriched axially chiral 2‐hydroxymethyl‐3‐naphthyl pyrroles under mild acidic conditions affords, after oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), the C4‐symmetric α,α,α,α‐atropenantiomer as an only isolable diastereomer. Both regioisomeric Ir(Por*)(CO)(Cl) complexes catalyze the carbene C−H insertion reaction affording the same enantiomer, albeit with slight difference in enantioselectivity. With the optimum Ir‐complex 3 e, the 2‐substituted arylacetic acid derivatives were generated from diazo compounds and cyclohexadiene in excellent yields and enantioselectivities.

Increasing enantioselectivity and reactivity in Ir-Catalysed intramolecular hydroamination reactions

A series of axially chiral NHC ligands bearing dialkylated naphthyl side arms and electron-rich substituted phenyl groups in the backbone have been employed in the synthesis of neutral NHC-Ir(COD)Cl complexes. When the halide ligand was abstracted from these compounds by appropriate silver salts AgX (X = PF6, NTf2), chiral cationic, formally 14-electron iridium complexes [(NHC)Ir(COD)][X] were formed. When these species were applied as catalysts for asymmetric intramolecular hydroamination of unactivated, amino-olefin substrates, chiral 5- and 6- membered N-heterocyclic products were obtained with moderate to excellent enantioselectivities. By tuning the substrate through variation of the N-protecting group on the amino-olefin substrates, remarkable improvements in enantioselectivity were obtained.

Non-Equilibrium Assembly of Atomically-Precise Copper Nanoclusters.

Accurate structure control in dissipative assemblies (DSAs) is vital for precise biological functions. However, accuracy and functionality of artificial DSAs are far from this objective. Herein, a novel approach is introduced by harnessing complex chemical reaction networks rooted in coordination chemistry to create atomically-precise copper nanoclusters (CuNCs), specifically Cu11(µ9-Cl)(µ3-Cl)3L6Cl (L = 4-methyl-piperazine-1-carbodithioate). Cu(I)-ligand ratio change and dynamic Cu(I)-Cu(I) metallophilic/coordination interactions enable the reorganization of CuNCs into metastable CuL2, finally converting into equilibrium [CuL·Y]Cl (Y = MeCN/H2O) via Cu(I) oxidation/reorganization and ligand exchange process. Upon adding ascorbic acid (AA), the system goes further dissipative cycles. It is observed that the encapsulated/bridging halide ions exert subtle influence on the optical properties of CuNCs and topological changes of polymeric networks when integrating CuNCs as crosslink sites. CuNCs duration/switch period could be controlled by varying the ions, AA concentration, O2 pressure and pH. Cu(I)-Cu(I) metallophilic and coordination interactions provide a versatile toolbox for designing delicate life-like materials, paving the way for DSAs with precise structures and functionalities. Furthermore, CuNCs can be employed as modular units within polymers for materials mechanics or functionalization studies.

Thermal, X-ray spectroscopy, morphological, density functional theory and molecular modeling studies on yttrium(III), germanium(IV), tungsten(VI), and silicon penicillinate antibiotic complexes

This manuscript elucidates the thermal stability analysis of four distinct penicillinate complexes, comprising yttrium(III), germanium(IV), tungsten(VI), and silicon, over a temperature ranging from 25 to 800°C. Thermal data revealed the high thermal stability nature of the decomposition steps. According to the spectroscopic measurements, the chemical formula of penicillinate complexes were [Y(Pin)2].Cl.6H2O complex (1), [Ge(Pin)2].2Cl.2H2O complex (2), [W(Pin)2].4Cl complex (3), and [Si(Pin)2].2Cl.2H2O complex (4). The powder XRD pattern revealed crystalline to polycrystalline natures. The synthesized penicillinate complexes were subjected to theoretical calculations utilizing density functional theory (DFT) calculations, employing the lanL2DZ/6-311G++ level of theory. The optimized geometry of each penicillinate complex was discerned, and a comprehensive evaluation of various properties, including the HOMO→LUMO electronic energy gap, molecular electrostatic potential map, and additional physical parameters, was conducted and validated against experimental findings. Molecular docking tool was used to explore the anticancer activity of the synthesized penicillinate complexes in comparison with penicillin potassium drug (Pin). For the computational investigation, two kinases — CSF1R (PDB ID: 7MFC) and MEK2 (PDB ID: 1S9I) associated with breast cancer progression and estrogen-dependent breast cancer were utilized. This comprehensive analysis provides a deeper understanding of the synthesized penicillinate complexes and their potential applications. KEY WORDS: Penicillinate complexes, TGA-DrTGA, TEM, XRD, DFT/TD-DFT, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(4), 973-988. DOI: https://dx.doi.org/10.4314/bcse.v38i4.13

Luminescent Pt(II) Complexes Using Unsymmetrical Bis(2-pyridylimino)isoindolate Analogues.

A series of ligands based upon a 1,3-diimino-isoindoline framework have been synthesized and investigated as pincer-type (N∧N∧N) chelates for Pt(II). The synthetic route allows different combinations of heterocyclic moieties (including pyridyl, thiazole, and isoquinoline) to yield new unsymmetrical ligands. Pt(L1-6)Cl complexes were obtained and characterized using a range of spectroscopic and analytical techniques: 1H and 13C NMR, IR, UV-vis and luminescence spectroscopies, elemental analyses, high-resolution mass spectrometry, electrochemistry, and one example via X-ray crystallography which showed a distorted square planar environment at Pt(II). Cyclic voltammetry on the complexes showed one irreversible oxidation between +0.75 and +1 V (attributed to Pt2+/3+ couple) and a number of ligand-based reductions; in four complexes, two fully reversible reductions were noted between -1.4 and -1.9 V. Photophysical studies showed that Pt(L1-6)Cl absorbs efficiently in the visible region through a combination of ligand-based bands and metal-to-ligand charge-transfer features at 400-550 nm, with assignments supported by DFT calculations. Excitation at 500 nm led to luminescence (studied in both solutions and solid state) in all cases with different combinations of the heterocyclic donors providing tuning of the emission wavelength around 550-678 nm.

Photoaquation of cis-[Rh(dppz)(phen)Cl2]Cl complex prospective as potential light-activated anti-cancer agent

The photoactivated drug usage in anti-cancer therapy, the working mechanism of which doesn’t rely on the formation of reactive oxygen species, allows reducing damage to healthy tissue by controlling toxicity. For instance, light-activated Rh(III) complexes show nuclease activity after irradiation with UV and visible light. However, literature analysis shows a lack of descriptions of basic photochemical mechanisms. Here we report the study of cis-[Rh(dppz)(phen)Cl2]Cl (DPPZPHEN, dppz is dipyrido[3,2-a:2′,3′-c]phenazine, phen is 1,10-phenanthroline) photochemistry in water solutions using stationary photolysis, nanosecond laser flash photolysis and ultrafast pump–probe spectroscopy. After the irradiation with 308 nm light, DPPZPHEN undergoes aquation, which results in the substitution of one chloride ligand by a water molecule and leads to the formation of [Rh(dppz)(phen)(H2O)Cl]Cl2. UV–vis spectra of complex and capillary electrophoresis data were collected and discussed. Laser flash photolysis (355 nm) demonstrates intermediate absorption attributed to the lowest electronic excited state (triplet) of the initial complex. The study of primary photophysical processes showed a rather complicated behavior of transient absorption, which could be described by a set of four exponential functions. The early photophysical processes were described by the scheme including the formation of two excited states of different natures, namely a dppz-based IL state and an LMCT state.

Exploiting hot electrons from a plasmon nanohybrid system for the photoelectroreduction of CO2

Plasmonic materials convert light into hot carriers and heat to mediate catalytic transformation. The participation of hot carriers (photocatalysis) remains a subject of vigorous debate, often argued on the basis that carriers have ultrashort lifetime incompatible with drive photochemical processes. This study utilises plasmon hot electrons directly in the photoelectrocatalytic reduction of CO2 to CO via a Ppasmonic nanohybrid. Through the deliberate construction of a plasmonic nanohybrid system comprising NiO/Au/ReI(phen-NH2)(CO)3Cl (phen-NH2 = 1,10-Phenanthrolin-5-amine) that is unstable above 580 K; it was possible to demonstrate hot electrons are the main culprit in CO2 reduction. The engagement of hot electrons in the catalytic process is derived from many approaches that cover the processes in real-time, from ultrafast charge generation and separation to catalysis occurring on the minute scale. Unbiased in situ FTIR spectroscopy confirmed the stepwise reduction of the catalytic system. This, coupled with the low thermal stability of the ReI(phen-NH2)(CO)3Cl complex, explicitly establishes plasmonic hot carriers as the primary contributors to the process. Therefore, mediating catalytic reactions by plasmon hot carriers is feasible and holds promise for further exploration. Plasmonic nanohybrid systems can leverage plasmon’s unique photophysics and capabilities because they expedite the carrier’s lifetime.

Preparation of a novel adsorbent with amino-rich carbon quantum dots for efficiently separating Zn(II) from Fe(II) in zinc deplating waste liquid

Zinc deplating waste liquid is considered hazardous due to the presence of heavy metal Zn(II) and hydrochloric acid, along with Fe(II). This study aims to develop a new adsorbent for efficient separation of zinc (II) from deplating waste liquid in a real factory. The novel adsorbent, PSCL-CQDs-NH2, was prepared by grafting home-made amino-rich carbon quantum dots (CQDs-NH2) onto a chloromethyl polystyrene resin matrix. It has been observed that amino groups can be protonated under strongly acidic conditions, enabling them to adsorb negatively charged Zn(II)-Cl complexes while repelling positively charged Fe(II)-Cl complexes. The grafted nano-size CQDs-NH2 can offer more adsorption positions to improve the adsorption properties. The results shown that PSCL-CQDs-NH2 presented higher Zn(II) adsorption capacity and better performance in separating Zn(II) from Fe(II) compared to the conventional anion exchange resin (717). At 298 K, PSCL-CQDs-NH2 showed a maximum Zn(II) adsorption capacity of 201.77 mg/g, and a selective Zn(II)/Fe(II) separation factor of 3033.72, which were 54.7% and 45.4 times higher than those of 717 resin. In the fixed bed adsorption process, PSCL-CQDs-NH2 exhibited 61.5% higher adsorption performance than 717 resin when treating actual zinc deplating waste liquid. Moreover, the water consumption during regeneration of PSCL-CQDs-NH2 is reduced by 10.3% compared to the 717 resin. These findings indicate that PSCL-CQDs-NH2 is an effective material for the treatment of industrial zinc deplating waste liquid.

Atropisomeric N‐Heterocyclic Carbene‐Palladium(II) Complexes: Influence of the Backbone Substitution

AbstractIn order to facilitate the synthesis of NHC precursors as well as to incorporate new moieties, the influence of the NHC backbone substitution was investigated within the concept of atropisomeric NHC‐metal complexes. A series of NHC precursors was prepared from new anilines and used to synthesize the corresponding Pd(allyl)Cl(NHC) complexes, most of the time as a mixture of diastereomers (meso and chiral). Chiral HPLC at preparative scale enabled to obtain enantiopure complexes in low to excellent yields. These complexes displayed good activity in the intramolecular α‐arylation of amides and, as a function of the structure of the chiral catalyst, excellent enantioselectivities were reached (up to 96 % ee).