Electron-donating Research Articles

Biomimetic nanosystems harnessing NIR-II photothermal effect and hypoxia-responsive prodrug for self-amplifying and synergistic tumor treatment

Tumor microenvironment-activated prodrugs have emerged as a promising strategy in precision medicine. However, the endogenous stimuli in the tumor microenvironment are often insufficient and unevenly distributed, impeding efficient and rapid prodrug conversion, necessitating the incorporation of complementary therapeutic strategies to amply treatment effectiveness. This study presents a self-synergistic therapeutic approach that combines hypoxia-activated paclitaxel prodrug (pro-PTX) with near-infrared-II (NIR-II) light-triggered photothermal therapy (PTT) for boosted tumor treatment. Initially, an organic polymer with strong NIR-II light harvesting capability, efficient photo-to-heat conversion, and excellent photostability was meticulously synthesized by introducing electron-withdrawing trifluoromethyl substituent. The high-performance NIR-II photothermal polymer then served as the matrix to encapsulate the hypoxia-responsive pro-PTX prodrug, forming the nanocore, on which the cell membrane derived from natural killer (NK) cells was further cloaked. The biomimetic nanopaltform exhibited a superior affinity towards tumor cells compared to normal cells, owing to the inherent tumor-recognition capability of NK cell membrane proteins. Upon exposure to NIR-II laser, the photothermal agent induced localized hyperthermia, facilitating not only direct tumor eradication but also exacerbating hypoxia within the tumor microenvironment. This, in turn, expedited the release of hypoxia-responsive prodrugs. Consequently, the synergistic effect of NIR-II PTT and chemotherapy efficiently induced cancer cell apoptosis and inhibited tumor growth. The developed nanoplatform, integrating hypoxia-responsive prodrug, high-performance NIR-II PTT agent-mediated complementary phototherapy, and NK cell-inspired active targeting, represents a promising strategy for precise and boosted tumor treatment.

Tailoring the photovoltaic performance of benzothiadiazole-based D–A-type polymers by incorporating robust electron-withdrawing substituents

The incorporation of electron-withdrawing substituents is one of the promising approaches to enhance the photovoltaic characteristics of p-type polymer donors. In this study, three benzothiadiazole (BT)-based D–A-type conjugated polymers decorated with different electron-withdrawing substituents were synthesized to understand the optimum constitution. First, a fluorinated alkylthienyl-substituted benzodithiophene donor was coupled with the BT acceptor via an alkylated thiophene bridge to yield the PB-BT reference. Subsequently, PB-BT was structurally modified by introducing strong electron-withdrawing F and CN units at the 5-position of the BT acceptor to afford two target polymers, PB-BTF and PB-BTCN, respectively. The optical, electrochemical, and photovoltaic properties of the three polymers were strongly dependent on the electron-withdrawing substituents. Notably, the polymer solar cell based on PB-BTF adopting the nonfullerene acceptor exhibited the highest power conversion efficiency (PCE) of 11.12 %, while those based on PB-BT and PB-BTCN exhibited PCEs of 9.56 % and 5.07 %, respectively. These results indicate that the choice of appropriate electron-withdrawing substituents is of great importance for developing high-performance BT-based D–A-type polymers.

Modulation of the Meisenheimer complex metabolism of nitro-benzothiazinones by targeted C-6 substitution

Tuberculosis, caused by Mycobacterium tuberculosis, remains a major public health concern, demanding new antibiotics with innovative therapeutic principles due to the emergence of resistant strains. Benzothiazinones (BTZs) have been developed to address this problem. However, an unprecedented in vivo biotransformation of BTZs to hydride-Meisenheimer complexes has recently been discovered. Herein, we present a study of the influence of electron-withdrawing groups on the propensity of HMC formation in whole cells for a series of C-6-substituted BTZs obtained through reductive fluorocarbonylation as a late-stage functionalization key step. Gibbs free energy of reaction and Mulliken charges and Fukui indices on C-5 at quantum mechanics level were found as good indicators of in vitro HMC formation propensity. These results provide a first blueprint for the evaluation of HMC formation in drug development and set the stage for rational pharmacokinetic optimization of BTZs and similar drug candidates.

Exploration of the synergistic effect of chrysene-based core and benzothiophene acceptors on photovoltaic properties of organic solar cells

To improve the efficacy of organic solar cells (OSCs), novel small acceptor molecules (CTD1–CTD7) were designed by modification at the terminal acceptors of reference compound CTR. The optoelectronic properties of the investigated compounds (CTD1–CTD7) were accomplished by employing density functional theory (DFT) in combination with time-dependent density functional theory (TD-DFT). The M06 functional along with a 6-311G(d,p) basis set was utilized for calculating various parameters such as: frontier molecular orbitals (FMO), absorption maxima (λmax), binding energy (Eb), transition density matrix (TDM), density of states (DOS), and open circuit voltage (Voc) of entitled chromophores. A red shift in the absorption spectra of all designed chromophores (CTD1–CTD7) was observed as compared to CTR, accompanied by low excitation energy. Particularly, CTD4 was characterized by the highest λmax value of 685.791 nm and the lowest transition energy value of 1.801 eV which might be ascribed to the robust electron-withdrawing end-capped acceptor group. The observed reduced binding energy (Eb) was linked to an elevated rate of exciton dissociation and substantial charge transfer from central core in HOMO towards terminal acceptors in LUMO. These results were further supported by the outcomes from TDM and DOS analyses. Among all entitled chromophores, CTD4 exhibited bathochromic shift (685.791 nm), minimum HOMO/LUMO band gap of 2.347 eV with greater CT. Thus, it can be concluded that by employing molecular engineering with efficient acceptor moieties, the efficiency of photovoltaic materials could be improved.

Malic Acid as a Green Catalyst for the N-Boc Protection under Solvent-free Condition

Abstract: A protocol for the Chemoselective N-Boc protection of various types of amines has been developed. This includes heteroaryl, aliphatic, and alicyclic amines. The process makes use of malic acid as a catalyst and operates efficiently at ambient temperature without the need for solvents. This technique has been proven to effectively protect a wide range of functionalized amines containing both electron-donating and electron-withdrawing substituents. The benefits of this method include its fast reaction rate, high selectivity, excellent yield, catalyst recyclability, and environmentally friendly conditions.

Quinoline Derivatives as Promising Scaffolds for Antitubercular Activity: A Comprehensive Review.

Heterocyclic compounds and their derivatives play a significant role in the design and development of novel quinoline drugs. Among the various pharmacologically active heterocyclic compounds, quinolines stand out as the most significant rings due to their broad pharmacological roles, specifically antitubercular activity, and their presence in plant-based compounds. Quinoline is also known as benzpyridine, benzopyridine, and 1-azanaphthalene. It has a benzene ring fused with a pyridine ring, and both rings share two carbon atoms. The importance of quinoline lies in its incorporation as a key component in various natural compounds found in medicinal plant families like Fumariaceae, Berberidaceae, Rutaceae, Papavaraceae, and others. This article is expected to have a significant impact on the advancement of effective antitubercular drugs. Through harnessing the potent activity of quinoline derivatives, the research aims to make valuable contributions to combating tuberculosis more efficiently and ultimately reducing the global burden of this infectious disease. Numerous nitrogen-containing heterocyclic compounds exhibit significant potential as antitubercular agents. These chemicals have fused aromatic nitrogen-heterocyclic nuclei that can change the number of electrons they have, which can change their chemical, physical, and biological properties. This versatility comes from their ability to bind with the receptors in multiple modes, a critical aspect of drug pharmacological screening. Among these compounds, quinoline stands out as it incorporates a stable fusion of a benzene ring with a pyridine nucleus. Quinolines have demonstrated a diverse range of pharmacological activities, including but not limited to anti-tubercular, anti-tumor, anticoagulant, anti-inflammatory, antioxidant, antiviral, antimalarial, anti-HIV, and antimicrobial effects. Some molecules, such as lone-paired nitrogen species, include pyrrole, pyrazole, and quinoline. These molecules contain nitrogen and take part in metabolic reactions with other molecules inside the cell. However, an excessive accumulation of reactive nitrogen species can lead to cytotoxicity, resulting in damage to essential biological macromolecules. Among these compounds, quinoline stands out as the oldest and most effective one, exhibiting a wide range of significant properties such as antitubercular, antimicrobial, anti-inflammatory, antioxidant, analgesic, and anticonvulsant activities. Notably, naturally occurring quinoline compounds, such as quinine, have proven to be potent antimalarial drugs. This review highlights quinoline derivatives' antitubercular potential, emphasizing recent research advancements. Utilizing IC50 values, the study emphasizes the efficacy of various quinoline substitutions, hybrids, and electron-withdrawing groups against MTB H37Rv. Continued research is essential for developing potent, low-toxicity quinoline derivatives to combat tuberculosis.

Novel phthalocyanines bearing 4-(2-isopropylphenoxy) groups: Synthesis, characterization, electrochemical and in-situ spectroelectrochemical properties

In this study, 4-(2-isopropylphenoxy)phthalonitrile (3) was prepared via a substitution reaction between 2-isopropylphenol (1) and 4-nitrophthalonitrile (2). Then, peripherally tetra 2-isopropylphenoxy substituted zinc(II) (4) and cobalt(II) (5) phthalocyanines were obtained via a cyclotetramerization reaction between phthalonitrile (3) and related metal salt. The structural characterization of synthesized compounds were completed via FT-IR, 1HNMR , UV–Vis and MALDI-TOF mass data. Electrochemical and spectroelectrochemical measurements were performed to determine the potential of novel phthalocyanines to be used in electrochemical applications. While the cobalt(II) phthalocyanine (5) displayed one metal-based reduction, two ring-based reductions and one metal and ring-based oxidation; zinc(II) phthalocyanine (4) showed three ring-based reductions and one ring-based oxidation reaction. In addition, it was determined that electron-releasing isopropyl phenoxy group affected half-wave peak potentials of complexes and the Q band positions. Diffusion-controlled, reversible and multi-electron transfer abilities of the zinc(II) (4) and cobalt(II) (5) phthalocyanines showed that they have redox richness for can be used in optical technological applications.

Construction and Electrochromic Properties of Two-Dimensional Covalent Organic Frameworks with Donor-Acceptor Structures of Triphenylamine and Bipyridine

The stacking between layers of a two-dimensional covalent organic framework (COF) leads to overlapping π orbitals, which enables charge carriers to be transported quickly through these pre-designed π orbitals. The two-dimensional COF featuring donor-acceptor interactions represents a straightforward approach for fabricating a high-performance organic electrochromic device. In this paper, N, N, N’, N’-tetrad(4-aminophenyl)−1,4-phenylenediamine (TPDA) with electron-rich structure and 2,2’-bipyridine-5,5’-dialdehyde (BPDA) with strong electron absorption ability were used as the construction unit. COFTPDA-BPDA electrochromic materials with donor-acceptor structure were synthesized by Schiff base reaction, which can achieve reversible switching from red to dark gray. The color/fade time of the film at 474 nm wavelength is 6.8 s/11.9 s. The contrast retention rate of the film can reach 97.6% after 20 potential cycles, the memory time is as long as 4278 s. The present study demonstrates that constructing a donor-acceptor (D-A) structural unit with conjugated triphenylamine as the electron donor linked to bipyridine electron-withdrawing groups enhances charge transfer and redox reactions. With the success of this design strategy, the construction of the D-A structure is an important methodology for improving the electrochromic properties of materials.

Modification Structure of Cinnamaldehyde with Primary Amines by Reflux and Sonication Methods in the Presence of Sulfuric Acid as a Catalyst

Cinnamon is one of the most valuable natural resources that sustains life and exists freely in nature. Cinnamaldehyde is the primary compound in cinnamon oil. It has a unique structure that contains a benzene ring, an aldehyde group, and an unsaturated double bond. Cinnamaldehyde has been structurally modified to improve biological activity. In this research, cinnamaldehyde and nitrophenyl amines were reacted with sulfuric acid as a catalyst by refluxing and sonication. UV-Vis Spectroscopy, FT-IR, 1H-NMR, and 13C-NMR were used to validate the chemical structures. Thin-layer chromatography (TLC) revealed a new single spot formed by the reaction of cinnamaldehyde and 4-amino-2-nitrophenol. By refluxing for 2 hours or sonicating for 30 minutes, a novel imine chemical, 4-nitro-2-((3-phenylallylidene)amino)phenol, was effectively synthesized with a yield of 75.21% or 83.71%, respectively. This imine was obtained as a dark red powder with a melting point of 237 °C. Meanwhile, only sonication produced a novel product from the reaction of cinnamaldehyde and 4-nitroaniline. However, the structural elucidation has not yet been performed because the yield was so low. Surprisingly, there was no reaction between cinnamaldehyde and 2,4-dinitroaniline. It was most likely owing to the amine’s bulky structure and the presence of two nitro groups in the amine as electron-withdrawing groups that reduced the nucleophilicity of the amine. We demonstrated that sonication is a suitable approach for imine synthesis, as it is commonly utilized in organic compound synthesis protocols.

Elevating Thermoelectric Performance by Compositing Dibromo-Substituted Thienoacene with SWCNTs.

Composites of organic small molecules (OSMs) and single-walled carbon nanotubes (SWCNTs) have drawn great attention as flexible thermoelectric (TE) materials in recent years. Here, we synthesized thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]thiophene (TTA) and 2,6-dibromothieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]thiophene (TTA-2Br) and compounded them with SWCNTs, obtaining thermoelectric TTA/SWCNT and TTA-2Br/SWCNT composites. The introduction of the electron-withdrawing Br group was found to decrease the highest molecular orbital energy level and bandgap (Eg) of TTA-2Br. As a result, the Seebeck coefficient (S) and power factor (PF) of the OSM/SWCNT composite films were significantly improved. Moreover, suitable energy barrier between TTA-2Br and SWCNTs facilitates the energy filtering effect, which further enhances thermoelectric properties of the 40 wt % TTA-2Br/SWCNT composite film with optimum thermoelectric properties (PF = 242.59 ± 9.42 μW m-1 K-2 at room temperature), good thermal stability, and mechanical flexibility. In addition, the thermoelectric generator (TEG) prepared using 40 wt % TTA-2Br/SWCNT composite films and n-type SWCNT films can generate an output power of 102.8 ± 7.4 nW at a temperature difference of 20 °C. This work provides new insights into the preparation of OSM/SWCNT composites with significantly enhanced thermoelectric properties.

Bis(imino)pyridyliron incorporated with NO2, F and benzhydryl substituents as thermostable precatalysts for vinyl-terminated polyethylenes

The electronic and steric properties of ligands are of great importance in late transition metal catalyst mediated ethylene polymerization to tune the catalytic performance. In this contribution, strong electron-withdrawing groups—fluoro and nitro—along with benzhydryl as a steric component, were incorporated into the parent bis(imino)pyridine ligand structure to prepare a series of iron (II) chloride complexes: 2-[MeC=N{2-(Ph2CH)-4-NO2-6-F}C6H2]-6-[MeC=N(Ar)C6H2]C5H3N–FeCl2 (Ar = 2,6-Me2C6H3Fe2Me, 2,6-Et2C6H3Fe2Et, 2,6-iPr2C6H3Fe2iPr, 2,4,6-Me3C6H2Fe3Me and 2,6-Et2-4-MeC6H2Fe2Et,Me). Apart from the structural characterization of all complexes executed via FTIR and elemental analysis, X-ray diffraction analysis unveiled distorted square pyramidal geometry for Fe2Me (τ5 = 0.21) and Fe2Et (τ5 = 0.28). Upon in situ activation with either MAO or MMAO cocatalysts, all iron complexes displayed distinguished polymerization performance, especially in terms of thermo-stability. In particular, the less hindered Fe2Me exhibited high activity: 20.4 × 106 g mol−1 h−1 at 70 °C, 1.5 × 106 g mol−1 h−1 at 110 °C, and 0.6 × 106 g mol−1 h−1 at 120 °C. Whereas, the sterically more hindered Fe2iPr proved to be more productive in generating high molecular weight polyethylene (Mw up to 410.7 kg mol−1 at 70 °C). Moreover, by adjusting the reaction temperature and ligand structure, the chain termination reaction could be modulated from a high proportion of vinyl-terminated polyethylene to saturated polyethylene rich product [CH2CH(CH2)nCH3/CH3(CH2)nCH3 = 0.7/0.3–0.39/0.61], as confirmed by high-temperature 1H/13C NMR spectra. Low molecular weight vinyl-terminated polyethylenes are of significant importance in the synthesis of functional polymers and can serve as valuable additives in lubricants.

Electron-Withdrawing Substituents Enhance the Type I PDT and NIR-II Fluorescence of BODIPY J Aggregates for Bioimaging and Cancer Therapy.

Organic dyes with simultaneously boosted near-infrared-II (NIR-II) fluorescence, type I photodynamic therapy (PDT), and photothermal therapy (PTT) in the aggregate state are still elusive due to the unclear structure-function relationship. Herein, electron-withdrawing substituents are introduced at the 5-indolyl positions of BODIPY dyes to form tight J-aggregates for enhanced NIR-II fluorescence and type I PDT/PTT. The introduction of an electron-rich julolidine group at the meso position and an electron-withdrawing substituent (-F) at the indolyl moiety can enhance intermolecular charge transfer and the hydrogen bonding effect, contributing to the efficient generation of superoxide radicals in the aggregate state. The nanoparticles of BDP-F exhibit NIR-II fluorescence at 1000 nm, good superoxide radical generation ability, and a high photothermal conversion efficiency (50.9%), which enabled NIR-II fluorescence-guided vasculature/tumor imaging and additive PDT/PTT. This work provides a strategy for constructing phototheranostic agents with enhanced NIR-II fluorescence and type I PDT/PTT for broad biomedical applications.

Tuning the photophysical properties of cyanine by barbiturate functionalization and nanoformulation for efficient optoacoustics- guided phototherapy

Cyanine derivatives are organic dyes widely used for optical imaging. However, their potential in longitudinal optoacoustic imaging and photothermal therapy remains limited due to challenges such as poor chemical stability, poor photostability, and low photothermal conversion. In this study, we present a new structural modification for cyanine dyes by introducing a strongly electron-withdrawing group (barbiturate), resulting in a new series of barbiturate-cyanine dyes (BC810, BC885, and BC1010) with suppressed fluorescence and enhanced stability. Furthermore, the introduction of BC1010 into block copolymers (PEG114-b-PCL60) induces aggregation-caused quenching, further boosting the photothermal performance. The photophysical properties of nanoparticles (BC1010-NPs) include their remarkably broad absorption range from 900 to 1200 nm for optoacoustic imaging, allowing imaging applications in NIR-I and NIR-II windows. The combined effect of these strategies, including improved photostability, enhanced nonradiative relaxation, and aggregation-caused quenching, enables the detection of optoacoustic signals with high sensitivity and effective photothermal treatment of in vivo tumor models when BC1010-NPs are administered before irradiation with a 1064 nm laser. This research introduces a barbiturate-functionalized cyanine derivative with optimal properties for efficient optoacoustics-guided theranostic applications. This new compound holds significant potential for biomedical use, facilitating advancements in optoacoustic-guided diagnostic and therapeutic approaches.

Organophotocatalyzed Cross Coupling of C- and Si-Radical to Access Dibenzylic Silanes from para-Quinone Methides and Silanecarboxylic Acids.

Herein we present a catalytic cross-coupling strategy between C-radicals and Si-radicals, enabling the efficient, gentle, and versatile synthesis of dibenzylic silanes from para-quinone methides and silanecarboxylic acids as the stable silyl radical precursors. The reaction is facilitated by an inexpensive organophotocatalyst and exhibits broad compatibility with various electron-donating and electron-withdrawing functional groups. Notably, mechanistic investigations suggest the involvement of dibenzylic and silyl radicals, underscoring a novel radical coupling mechanism that introduces a fresh perspective on C-Si bond formation.

Ir(I)-Bi(III) Donor-Acceptor Adducts Stabilized by Dispersion Interactions between the Metal Pincer Ligands and Their Possible Self-Assembly Forming Molecular 1D Semiconductors.

Structure, stability, and electronic properties of the bimetallic {[IrI(terpy)(Me)]-[BiIIINNN]}n monomeric, oligomeric, and polymeric structures (n = 1-3 and ∞; terpy = terpyridine; Me = methyl; BiNNN = bismuth triamide) and their derivatives (designated as (Bi·Ir)n structures) were studied theoretically by DFT cluster and periodic calculations. Stable Bi·Ir adducts (monomers) were formed with short Bi-Ir bonds (<2.7 Å) and Gibbs free binding energies larger than 20 kcal/mol for all systems. The substitution of the pincer ligands of Ir(I) and Bi(III) complexes by the electron-donating (NH2) and electron-withdrawing (NO2, F, CF3) groups, respectively, enhanced the Ir → Bi charge transfer, substantially stabilizing the Bi·Ir monomers. The monomers from the unsubstituted complexes can be considered as dispersion stabilized adducts, and they may form spontaneously (Bi·Ir)n layered oligomers/polymers with semiconducting properties. The self-assembly of monomers into oligomers/polymers is hindered by bulkier protecting groups on the Bi(III) complex, such as tBu and SiMe3.

Effect of different substituent on the ESIPT process and fluorescence features of 2-(2-hydroxyphenyl)benzoxazole derivatives: A DFT/TD-DFT study

In this contribution, four derivatives of 5′-(para-R-Phenylene) vinyl-2-(2′-hydroxyphenyl) benzoxazole (PVHBO) were ingeniously designed by introducing two electron-withdrawing substituents and two electron-donating substituents, aiming to investigate the influence of different substituents on the photophysical properties of PVHBO and the excited state intramolecular proton transfer (ESIPT) process via the density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. By utilizing the geometric parameters and the simulated infrared (IR) spectra, we compared the intramolecular hydrogen bonds (IHBs) strengths in the S0 and S1 states of the molecules. Via conducting the hole-electron analysis, the reduction in fluorescence intensity for the enol and keto forms of PVHBO, PVHBO-MeO, and PVHBO-NH2 were also well explicated. Besides, the potential energy curves (PECs) and corresponding transition state (TS) structures for both S0 and S1 states were also constructed to accurately obtain energy barriers of forward and reversed proton transfer processes. The calculated absorption and fluorescence spectra also show that PVHBO-NH2 has the largest Stokes shifts of 158 nm and 219 nm in both the enol and keto states, with a significant increase in fluorescence intensity observed upon the induction of electron-withdrawing groups. Through this work, it can provide the theoretical basis for the design of novel luminescent materials.

Electronic Control of Polyproline II Helix Stability via the Identity of Acyl Capping Groups: the Pivaloyl Group Particularly Promotes PPII.

The type II polyproline helix (PPII) is a fundamental secondary structure of proteins, important in globular proteins, in intrinsically disordered proteins, and at protein-protein interfaces. PPII is stabilized in part by n→π* interactions between consecutive carbonyls, via electron delocalization between an electron-donor carbonyl lone pair (n) and an electron-acceptor carbonyl (π*) on the subsequent residue. We previously demonstrated that changes to the electronic properties of the acyl donor can predictably modulate the strength of n→π* interactions, with data from model compounds, in solution in chloroform, in the solid state, and computationally. Herein, we examined whether the electronic properties of acyl capping groups could modulate the stability of PPII in peptides in water. In X-PPGY-NH2 peptides (X=10 acyl capping groups), the effect of acyl group identity on PPII was quantified by circular dichroism and NMR spectroscopy. Electron-rich acyl groups promoted PPII relative to the standard acetyl (Ac-) group, with the pivaloyl and iso-butyryl groups most significantly increasing PPII. In contrast, acyl derivatives with electron-withdrawing substituents and the formyl group relatively disfavored PPII. Similar results, though lesser in magnitude, were also observed in X-APPGY-NH2 peptides, indicating that the capping group can impact PPII conformation at both proline and non-proline residues. The pivaloyl group was particularly favorable in promoting PPII. The effects of acyl capping groups were further analyzed in X-DfpPGY-NH2 and X-ADfpPGY-NH2 peptides, Dfp=4,4-difluoroproline. Data on these peptides indicated that acyl groups induced order Piv- > Ac- > For-. These results suggest that greater consideration should be given to the identity of acyl capping groups in inducing structure in peptides.

Local charge redistribution enables single ionic conductor for fast charge solid Li battery

Solid polymer electrolytes (SPEs) have been regarded as hopeful candidate electrolyte for solid-state lithium battery. However, the low Li+ transference number and poor interface stability pose great challenges for the high rate capability of SPE. Herein, inspired from the density functional theory (DFT) calculations that local positive charge distribution can be regulated by introducing strong electron-withdrawing groups, which can selectively anchor TFSI−, largely enhance the Li+ transference number. As predicted, the obtained CPE-NO2 deliver a remarkable Li+ transference number of 0.91, equal to a single-ion conductor for Li+, largely high than that of the SPE (0.31), according well with the molecular dynamics (MD) simulations and pyridine complexation experiments. Furthermore, the PEO||Li interfacial stability, flame retardant ability, and mass transfer of Li+ in interface can also be largely enhanced by interfacial by-product, which are fast Li+ conductors according to TOF-SIMS results. Impressively, the Li|CPE-NO2|Li cell exhibit superior cyclability for 2200 h at 0.1 mA cm−2, and the solid LFP|CPE-NO2|Li battery delivers prominent capacity of 127.4 mAh g−1 at a high rate 5 C (12 mins). This work breaks the fast charge limitation of solid lithium battery, and provides a feasible approach for the construction of advanced solid electrolyte.

Harnessing synergistic effects in GQD@Pt(II) nanocomposites for enhanced photovoltaic performance: a computational study.

The development of efficient solar energy conversion technologies is crucial for addressing global energy challenges and reducing reliance on fossil fuels. Platinum(II) complexes are promising materials for photovoltaic applications due to their strong light absorption and long-lived excited states. However, their narrow absorption in the visible spectrum and stability issues limit their performance. Combining platinum(II) complexes with graphene quantum dots (GQDs) can enhance photovoltaic performance by leveraging the complementary light harvesting and charge transfer characteristics of the two components. This study utilizes density functional theory (DFT) calculations to explore their electronic structures, charge transfer dynamics, and photoelectric performance. Specifically, it investigates the effects of incorporating different substituents, either electron-donating or electron-withdrawing, onto the fluorene motif of the Pt(II) complex. The findings reveal that combining GQDs with Pt(II) complexes extends light absorption into the UV range, enabling comprehensive solar utilization. Upon photoexcitation, electrons migrate between the GQD conduction band and the Pt(II) complex, stabilizing charges and enhancing extraction. Substituents significantly influence charge transfer dynamics: electron-withdrawing groups promote transfer to the GQD, while electron-donating groups encourage charge separation and delocalization. Nanocomposites featuring electron-donating substituents achieve the highest energy conversion efficiencies, with GQD@Pt(II)-NPh2 reaching 24.6%. This is attributed to improved light harvesting, efficient charge injection, and reduced recombination. These insights guide the rational design of GQD-Pt(II) nanocomposites, optimizing charge separation and transfer processes for enhanced photovoltaic performance. The computational approach employed here provides a robust tool for developing advanced materials in renewable energy technologies. The computational studies reported in this work were performed using the DFT approach, specifically employing the hybrid functional PBE0. The PBE0 functional's accuracy in describing electronic structures and excited-state properties is essential for understanding charge transfer processes, photoabsorption, and emission characteristics in metal-organic complexes. Geometry optimizations and time-dependent DFT (TD-DFT) calculations were carried out to investigate the properties of the nanocomposites. The effects of solvents were replicated using the conductor-like polarizable continuum model (CPCM). The charge transfer length (ΔL) and interfragment charge transfer (ΔQ) were calculated using the Multiwfn software package, and all calculations were performed using the BDF software package.

Supercapacitive investigation of polyazomethine incorporating electron-withdrawing Nitro Group: Room temperature synthesis

A polyazomethine, designated as NAZ, was synthesized effortlessly at room temperature via a highly efficient polycondensation route employing 5,5′-(4-nitro-1,2-phenylene)bis(furan-2-carbaldehyde) (III) as a monomer, along with a diverse array of diamines meticulously selected for engineering the NAZ polyazomethine. The resulting NAZ material underwent a comprehensive characterization employing cutting-edge techniques including X-ray diffraction (XRD), the random morphology of polyazomethine has revealed in FESEM and TEM images, energy dispersive X-ray analysis (EDAX), and a suite of advanced spectroscopic methods. In the realm of Fourier-transform infrared spectroscopy (FTIR), the emergence of the distinctive –CHN– peak at 1608 cm−1 unequivocally validated the triumphant conversion of dicarbaldehyde (III) and diamines into the desired polyazomethine structure. XRD diffractograph unveiled the tantalizingly amorphous disposition of NAZ, while the FESEM images elegantly revealed its enigmatic and inherently random morphology. The EDAX analysis, meanwhile, provided an exquisite insight into the intricate chemical composition and elemental distribution meticulously orchestrated on the surface of NAZ. Delving into the electrochemical domain, the synthesized polyazomethine electrodes were subjected to a rigorous battery of tests including cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and the formidable electrochemical impedance spectroscopy (EIS). The superlative supercapacitive prowess of the NAZ electrodes were fervently evaluated across a plethora of electrolytic environments encompassing NaOH, LiCl, NaNO2, and the venerable KOH, spanning an impressive range of concentrations. Noteworthy is the awe-inspiring performance of the NAZ electrode in the hallowed 1 M KOH electrolyte, boasting an unprecedented specific capacitance (Cp) of 860 Fg−1, specific energy (SE) soaring to an impressive 6.14 Whrkg−1, and specific power (SP) scaling the summit at a staggering 74 KWkg−1, thus epitomizing optimal performance in every facet.Furthermore, the indomitable NAZ electrode exhibited an unparalleled degree of stability, steadfastly retaining a remarkable 69.25 % of its initial capacitance even after being subjected to the rigorous crucible of successive 1000 cycles within the exacting confines of the 1 M KOH electrolyte.