Halogen Research Articles

In-situ Polymerization Induced Seed-Root Anchoring Structure for Enhancing Stability and Efficiency in Perovskite Solar Modules.

The escape of organic cations over time from defective perovskite interface leads to non-stoichiometric terminals, significantly affecting the stability of perovskite solar cells (PSCs). How to stabilize the interface composition under environmental stress remains a grand challenge. To address this issue, we utilize thiol-functionalized particles as a "seed" and conduct in situ polymerization of 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA) as a "root" at the bottom of the perovskite layer. In this process, the thiol group acts as the initiation site for the polymerization of HFMA, while the fluorine groups in HFMA firmly anchor the organic cations of the perovskite through multiple hydrogen bonds. This strategy resembles how seeds take root in soil to prevent soil erosion. This bionic seed-rooting structure effectively stabilizes the stoichiometry of the perovskite, thus suppressing the escape of organic cations. As a result, the perovskite films with seed-rooting structures exhibit enhanced stability under harsh vacuum thermal conditions (150 °C, < 10 Pa). The resulting PCS achieves an efficiency of 25.64% and a 22.4 cm2 module efficiency of 22.61%. After 1300 hours of 1-sun illumination at 85% relative humidity and 65 °C (ISOS-L-3 protocol), the perovskite solar module maintains 90% of its initial efficiency.

SN2-Reaction-Driven Bonding-Heterointerface Strengthens Buried Adhesion and Orientation for Advanced Perovskite Solar Cells.

Traditionally weak buried interaction without customized chemical bonding always goes against the formation of high-quality perovskite film that highly determines the efficiency and stability of perovskite solar cells. To address this issue, herein, we propose a bimolecular nucleophilic substitution reaction (SN2) driving strategy to idealize the robust buried interface by simultaneously decorating underlying substrate and functionalizing [PbX6]4- octahedral framework with iodoacetamide and thiol molecules, respectively. Theoretical and experimental results demonstrate that a strong SN2 reaction between exposed halogen and thiol group in two molecules occurs, which not only benefits the reinforcement of buried adhesion, but also triggers target-point-oriented crystallization, synergistically upgrading the upper perovskite film quality and accelerating interfacial charge extraction-transfer behavior. Benefiting from the suppressed nonradiative recombination, as a result, an all-air-processed carbon-based all-inorganic CsPbI2Br device achieves an enhanced efficiency of 15.14%, more importantly, with significantly prolonged long-term stability under harsh conditions. This unique reaction-driven buried interface provides a new path for manipulating perovskite growth and obtaining advanced perovskite photovoltaics.

Anticancer and Antimicrobial Activity of Copper(II) Complexes with Fluorine-Functionalized Schiff Bases: A Mini-Review

In recent years, metallodrugs have emerged as captivating and promising compounds in the fields of cancer therapy and antimicrobial agents. While noble metals have shown remarkable biological activity, increasing interest lies in utilizing more abundant and cost-effective metals in medicinal chemistry. This is primarily due to their pivotal role in biological processes and their lower cost compared to precious metals. Among these, copper(II) complexes have emerged with promising applications in medicine. Notably, copper compounds bearing Schiff bases stand out as innovative metallodrugs. They exhibit intriguing cytotoxic properties against a wide range of cancer cell lines, while also demonstrating inhibitory effects on prevalent bacterial and fungal strains. Nevertheless, research into Cu(II) complexes with Schiff bases remains of paramount interest. One strategic avenue to bolster their biological activity involves the introduction of fluorine groups into the ligands. This approach has demonstrated a significant augmentation in efficacy and selectivity, particularly in targeting cancer cells and microbial pathogens, because fluorine incorporation can improve metabolic stability and cellular uptake. This further reinforces the therapeutic potential of these metallodrugs. Thanks to these promising outcomes, research into the development of Cu(II) complexes with fluorinated Schiff bases is advancing significantly. This holds immense potential for progressing the field of medicinal chemistry, with the aim of addressing unmet clinical needs in both cancer therapy and antimicrobial treatment. This review comprehensively explores the latest advancements in Cu(II) complexes bearing fluorinated Schiff bases, encompassing diverse coordination modes. It delves into their scope and applications in cytotoxic evaluations, as well as their efficacy as antimicrobial and antifungal agents.

Diving into Unknown Waters: Water-Soluble Clickable Au13 Nanoclusters Protected with N-Heterocyclic Carbenes for Bio-Medical Applications.

The use of gold nanoclusters in biomedical applications has been steadily increasing in recent years. However, water solubility is a key factor for these applications, and water-soluble gold nanoclusters are often difficult to isolate and susceptible to exchange or oxidation in vivo. Herein, we report the isolation of N-heterocyclic carbene (NHC)-protected atomically precise gold nanoclusters functionalized with triethylene glycol monomethyl ether groups. These clusters are highly luminescent and water soluble and are shown to be stable in biological media. Importantly, the core structure, stability, and high quantum yield of the nanoclusters were conserved after backbone modification. Depending on the nature of the halide group, clusters have high stability in simulated biofluids and resist attack by glutathione. In vivo studies show that no abnormal cellular morphology is introduced in the kidney, liver, or spleen of mice treated with [Au13(NHC)5Br2]Br3 nanoclusters protected by 1,8-dimethylnaphthyl-linked NHCs. This cluster has a blood elimination half-life of 0.68 h. Functionalization of the wingtip groups of the cluster with azide groups is demonstrated, and complete reaction of all 10 azide groups with strained alkynes is shown, highlighting the potential of these clusters in biological settings.

Halogen-Bearing Peptide Liquid Crystals to Elicit Molecular Alignments for Residual Dipolar Coupling Measurement.

Residual dipolar coupling (RDC) not only contributes to the dynamic analysis of proteins but also provides a robust route for the structure determination of small organic compounds. An essential prerequisite for this methodology is the availability of alignment media. Herein, a series of novel peptide-based alignment media are generated by introducing D-type or halogen-bearing amino acids for RDC measurements. Compared with a self-assembled peptide liquid crystal (LC) medium containing D-amino acid, the incorporation of halogen elements improved the electronegativity of peptide LCs, resulting in enhanced alignment strength toward analytes. Meanwhile, halogen-bearing peptide LCs can provide different orientations relative to non-halogenated peptide media, allowing the acquirement of independent sets of RDCs. The presented peptide LCs not only enrich the existing alignment media but also ignite a way of creating multiple alignment media for independent, non-linearly related sets of RDC measurement.

Relativistic effects on Properties of Halogen Group Elements/Ions

Relativistic effects on Properties of Halogen Group Elements/Ions

Exploring the Fluorination and Hydroxylation of Pore-Space-Partitioned Metal-Organic Frameworks for C2H2/CH4 Separation.

We report three novel pore-space-partitioned metal-organic frameworks (MOFs) functionalized with fluorine and hydroxyl groups using 2,3,5,6-tetrafluorobenzene-1,4-dicarboxylic acid (F4-BDC) and a new ligand 3,6-difluoro-2,5-dihydroxybenzene-1,4-dicarboxylic acid (F2(OH)2-BDC) as organic building blocks, with 1,3,5-tris(4-pyridyl)-2,4,6-triazine (TPT) as pore partition agent. With the polar fluorine and hydroxyl groups and the open metal sites being blocked by TPT, moderate molecule-framework interactions can be engineered. These three isoreticular microporous frameworks Mn-TPT-BDC-F4 (NCKU-21), Mn-TPT-BDC-F2(OH)2 (NCKU-22), and Mg-TPT-BDC-F2(OH)2 (NCKU-23) (NCKU=National Cheng Kung University) exhibit distinct single-component gas adsorption behaviors. Although NCKU-22 uptakes a much lower amount of C2H2 compared to NCKU-21 and -23, dynamic breakthrough experiments show that these three materials are all capable of efficient C2H2/CH4 separations. These MOFs possess moderate isosteric heat of adsorption for C2H2 (25.7-32.1 kJ mol-1), allowing easy regeneration and energy-efficient C2H2/CH4 separations.

Discovery of a Novel p38α-MK2 Complex Inhibitor as a Potential Choice for Autoimmune Diseases.

The p38α-MK2 signaling axis plays an important role in the inflammatory response of cells. Here, we carried out a series of optimizations on CDD-450, aiming to enhance inhibition of the p38α-MK2 complex and improve pharmacokinetic properties. First, the magic F strategy was utilized to obtain compound 21, which displayed a 60-fold increase in tumor necrosis factor α inhibition and a 600-fold increase in interleukin-6 inhibition. Molecular dynamics simulations revealed insights into the binding mode of fluorinated molecules. Subsequently, introducing a methyl group and a fluorine group led to compound 36, which showed improved pharmacokinetic properties in rats and dogs. Evaluation in the Lewis rat adjuvant-induced arthritis model showed that compound 36 had a robust inflammation inhibitory effect and joint repair ability. Currently, compound 36 is being considered for preclinical development as a potential treatment for inflammatory diseases.

Impact of Halogen Groups on the Properties of PEA‐Based 2D Pb–Sn Halide Perovskites

Impact of Halogen Groups on the Properties of PEA‐Based 2D Pb–Sn Halide Perovskites

Synthesis and Evaluation of Antibacterial and Antifungal Activities In vitro and In silico of Novel Morpholinoalkoxychalcones

Introduction: Chalcone compounds exhibit diverse bioactivities, attracting significant interest. Morpholine is a heterocycle commonly used in medicinal chemistry. It could enhance the potency, pharmacokinetics, and bioactivities of its compounds. Methods: Adding morpholine into the chalcone scaffold could help create new compounds with favorable bioactivities. In this study, a new parallel synthesis procedure has been developed. Using this procedure, 18 novel morpholinoalkoxychalcones have been successfully synthesized. They had chains with morpholine appended on ring A or ring B. All the synthesized compounds were evaluated for the antibacterial and antifungal activities by agar diffusion method on 5 bacteria and 2 fungi strains. Results: The compounds with good inhibition were determined with respect to the MIC values by the agar dilution method. Among the tested compounds, B.21 was found to be the best against E. faecalis, with an MIC value of 0.6 mM. B.43 with an MIC value of 2.04 mM has displayed its potential in inhibiting A. niger and C. albicans the best among other compounds. Conclusion: The in silico study has revealed two targets to align with the in vitro results. Longer alkyl chains have enhanced the activity, along with the presence of OH, NH2, and halogen groups on both rings A and B.

Chemoselective homologative preparation of trisubstituted alkenyl halides from carbonyls and carbenoids.

The chemoselective synthesis of trisubstituted alkenyl halides (Cl, Br, F, I) starting from ketones and aldehydes and lithium halocarbenoids is reported. Upon forming the corresponding tetrahedral intermediate adduct, followed by the addition of thionyl chloride, a selective E2-type elimination is triggered, furnishing the targeted motifs. The transformation takes place under full chemocontrol: various sensitive functionalities (e.g. ester, nitrile, nitro, or halogen groups) can be placed on the starting materials, thus documenting a wide reaction scope, as well as the application of the technique to biologically active substances.

Enhancing optoelectronic performance of organic solar cells: Alkoxy substitution of central cores and π-bridge units in fully non-fused ring electron acceptors

To systematically elucidate the impact of fluorination and alkoxy modification on the fully non-fused ring electron acceptors (NFREAs) for organic solar cells (OSCs), six fully NFREAs were engineered featuring a benzene core, a selenophene-thiophene unit as the π-bridge, and IC-2F end groups. The derivatives R-D2F and R-D2O were designed by introducing para-substituted fluorine and alkoxy groups onto the central benzene ring of R. Further modifications to the π-bridge of R-D2O, involving variations in the position and number of alkoxy groups, resulted in the derivatives R-DW4O, R-DN4O, and R-D6O. Molecular Dynamics (MD), Density Functional Theory (DFT), and Time-Dependent Density Functional Theory (TD-DFT) simulations were used to predict the optoelectronic properties of these compounds. A comprehensive analysis was conducted on aspects including intramolecular non-covalent interactions, transition density matrix (TDM), electron-hole distributions, charge density difference (CDD), and inter-fragment charge transfer (IFCT). Additionally, the electron transfer rate constants (Ke) and electron mobility (μe) of dimeric structures were calculated to better understand the electronic transmission behavior of these acceptor molecules. The results show that alkoxy substitution on the central core, rather than fluorine substitution, enhances planarity, strengthens intermolecular interactions, reduces the energy gap, induces a red shift in the absorption spectrum, and improves electron excitation efficiency and net charge transfer. The addition of alkoxy groups to the π-bridge further promotes non-covalent interactions, enhancing light absorption and increasing light harvesting efficiency (LHE). Among the derivatives, R-D6O, which features cooperative alkoxy substitution on both the thiophene and selenophene units, exhibits the highest electron mobility, making it a promising candidate for OSC applications. These findings provide valuable insights into the design of high-performance fully NFREAs for OSCs.

Bischalcone derivatives with fluorine and methoxy functional groups: Synthesis, molecular docking, and biological evaluation as potential anticancer agents

Bischalcone derivatives with fluorine and methoxy functional groups: Synthesis, molecular docking, and biological evaluation as potential anticancer agents

Efficient synthesis of promising antidiabetic triazinoindole analogues via a solvent-free method: investigating the reaction of 1,3-diketones and 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole-3-thione.

Diabetes poses a significant global health challenge, driving the search for effective management strategies. In the past years, α-amylase inhibitors have emerged as promising candidates for regulating blood sugar levels. In this concern, we have synthesized a series of novel 3-methyl-2-aroylthiazolo[3',2':2,3][1,2,4]triazino[5,6-b]indole derivatives via the regioselective reaction of 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole-3-thione and 1,3-diketones in the presence of NBS under solvent-free conditions. Subsequently, the inhibitory potential of the newly synthesized 3-methyl-2-aroylthiazolo[3',2':2,3][1,2,4]triazino[5,6-b]indole derivatives was assessed against the α-amylase enzyme to probe their antidiabetic properties. In vitro studies revealed moderate to excellent α-amylase inhibitory activity, with IC50 values ranging from 16.14 ± 0.41 to 27.69 ± 0.58 μg ml-1. Furthermore, SAR analysis showed that compounds containing halogen groups exhibited superior inhibition potential, surpassing the standard drug Acarbose (IC50 = 18.64 ± 0.42 μg ml-1), particularly derivatives substituted with 4-fluoro and 2,4-dichloro groups, with IC50 values of 16.14 ± 0.41 μg ml-1 and 17.21 ± 0.15 μg ml-1, respectively. Additionally, molecular docking unveiled the binding modes of ligands with the active site of A. oryzae α-amylase. Encouragingly, the theoretical analyses closely mirrored the experimental findings, further underlining the promise of these synthetic molecules as potent α-amylase inhibitors.

Sugar additive with a halogen group enabling a highly reversible and dendrite-free Zn anode

Sucralose, a weakly polar sugar electrolyte additive containing halogen elements, enables a highly reversible and dendrite-free Zn anode.

Discovery of novel fluorine-containing parthenolide analogues as potential antitumor agents.

Incorporating fluorine-containing groups into the chemical skeleton is expected to enhance bioactivity and bioavailability. Directly introducing fluorine groups into the parthenolide skeleton remains challenging and limited. In this research, a series of novel fluorine-containing parthenolide derivatives were synthesized through late-stage diversification strategy. And the most promising derivate 1 exhibited good antiproliferative activity against NCI-H820 (IC50: 2.66μM), Huh-7 (IC50: 2.36μM), and PANC-1(IC50: 2.16μM). The preliminary mechanism study indicated compound 1strongly inhibited the colony formation number of NCI-H820, Huh-7 and PANC-1cells and inhibited lung cancer metastasis with a dose-dependent manner through inhibiting STAT3 signaling pathway. Compound 16, a prodrug of compound 1, showed a significant improvement in aqueous solubility and oral bioavailability compared with parthenolide. Moreover, compound 16 significantly suppressed tumor growth in lung patient-derived tumor xenograft model without obvious toxicity. Based on the above results, we propose that compound 16 may be a promising lead compound for treatment of lung cancer.

B12-Dependent Radical SAM Enzymes Catalyze C-Fluoromethylation via a CH2F-Cobalamin Intermediate.

Fluorine and fluorine-containing functional groups play important roles in drugs and agrochemicals. Recently, SAM-dependent methyltransferases and several SAM analogues have been reported for fluoromethyl transfer through a nucleophilic mechanism. However, fluoromethylation of unactivated carbon centers is very challenging, and their substitution usually involves a radical mechanism. To date, no biocatalysts have been developed for fluoromethylation of unactivated carbon centers. In this study, we found that the B12-dependent radical SAM methyltransferase (B12-RSMT) QCMT can fluoromethylate the glutamine Cα position of peptides with fluorinated SAM (F-SAM) generated in situ by the enzyme AclHMT. QCMT can cleave F-SAM to produce the 5'-dA radical. The significant reaction intermediate CH2FCbI was characterized by HR-MS, 19F NMR spectroscopy and X-ray crystallography. In addition, B12-RSMTs CysS and GenD1 can also transfer fluoromethyl groups onto natural products. We also found that F-SAM is not compulsory. The reduced B12-RSMTs can directly generate CH2FCbI with CH2FI and transfer the CH2F group when SAM is used as the radical initiator. Our results demonstrate a radical-mediated enzymatic strategy for fluoromethylation with abiological cofactors and expand radical SAM enzymes to the field of fluorine chemistry.

Phytotoxicity Study of (Amino)imidazo[1,2-a]pyridine Derivatives Toward the Control of Bidens pilosa, Urochloa decumbens, and Panicum maximum Weeds.

In this work, several imidazo[1,2-a]pyridines were synthesized through the Groebke-Blackburn-Bienaymé three-component reaction (GBB-3CR), and their phytotoxicity was evaluated in vitro by the influence on the growth of wheat coleoptiles and three important agricultural seeds (Allium cepa, Lactuca sativa, and Solanum lycopersicum) at test concentrations of 1000, 300, 100, 30, and 10 μM. A structure-activity relationship was established, showing the importance of halogen groups at the ortho position of the attached aromatic ring and the presence of a cyclohexylamine group for greater activity. Post-modification of some GBB-3CR adducts was carried out, leading to imidazo[1,2-a]pyridine-tetrazole hybrids, which were also evaluated in these bioassays. The phytotoxicity on seed germination and growth bioassays demonstrated that A. cepa was the most susceptible seed, and the most affected parameters were the root and shoot lengths. The most active compound was also evaluated against Bidens pilosa, Urochloa decumbens, and Panicum maximum weeds under hydroponic conditions to assess its phytotoxic potential at a more advanced level of bioassays. Promising results were also achieved, in which the most affected growth factor by inhibition was the root growth, and a stimulus to shoot growth was noted, making it a promising hit in the search for new herbicides.

A theoretical study of the bond-dissociation enthalpies (BDH), N–R bond lengths and proton affinities of N-substituted pyrroles, imidazoles and pyrazoles with R substituents along the periodic table

The properties (geometry, bond-dissociation enthalpies and proton affinities) of three azoles, pyrrole, imidazole and pyrazole, with twenty-two N-substituents R covering a significant part of the periodic table [1 (lithium group, alkaline), 2 (beryllium group, alkaline earth), 13 (boron group, triel), 14 (carbon group, tetrel), 15 (nitrogen group, pnictogen), 16 (oxygen group, chalcogen) and 17 (fluorine group, halogen) of the periods 2, 3 and 4 plus the hydrogen] have been calculated with the G4 composite ab initio method. These three properties were discussed with regard to the azole and to the group R using as model compound the amines H2N–R. The large set of compounds and their consistency allowed finding many equations that related different calculated properties. General properties such as bond-dissociation enthalpies, BDH, N–R bond lengths and proton affinities were tested in search of simple equations that explain the calculated properties.Graphical abstract

High Color Purity Deep‐Blue Multi‐Resonance TADF Material with Narrowband Emission Toward BT.2020 Standard

AbstractDue to higher exciton energy, the deep‐blue organic light‐emitting diodes (OLEDs) are the most challenging among trichromatic emitters. In this work, three novel blue emitters with multi‐resonance (MR) effects are reported based on N,N,5,9‐tetraphenyl‐5,9‐dihydro‐5,9‐diaza‐13b‐boranaphtho[3,2,1‐de]anthracen‐7‐amine (PAB) skeleton, incorporating fluorine and methyl groups. Compound 2FPAB and MePAB exhibit ultra‐pure deep‐blue emission peaks at 436 and 448 nm respectively. The device based on MePAB achieves a maximum external quantum efficiency of 19.8% with an ultralow CIEy value of 0.046 and a full‐width‐at‐half‐maximum (FWHM) of 29 nm in the bottom emitting device. Additionally, the peripheral cladding of fluorine atoms extends the conjugation framework and slightly enhances the electron acceptance character of the boron atom at the ortho‐position. This leads to a redshift in the emission spectrum and enhanced photoluminescence quantum yield (PLQY) of up to 93% for MePABF. Furthermore, the potential application of MePAB as a deep‐blue sensitizer for MePABF is examined by fabricating a TADF‐sensitized‐TADF (TST) device. The results show a significantly reduced efficiency roll‐off and improved device performance, with a maximum external quantum efficiency (EQEmax) of 25.1% and a FWHM of 29 nm.