Search Results (32)

There are few examples of covalent organic frameworks (COFs) based on phosphorus as the building element, probably because the structure of most phosphorus derivatives is pyramidal, which may prevent the stacking expected for classical 2-dimensional COFs. In addition, they are generally associated with linear difunctional derivatives. In this paper is reported the original association of a trifunctional 3-D compound with a trifunctional 2-D compound in an attempt to get a new COF. The condensation reaction between a thiophosphate derivative bearing three aldehydes and the trihydrazinotriazine has been carried out with the aim of obtaining either a COF or simply a porous organic polymer (POP), consisting in both cases of associated macrocycles, affording a new covalent triazine framework (CTF). The material resulting from this condensation has been characterized by multinuclear MAS NMR (³¹P, ¹H, and ¹³C), IR, and thermogravimetric analysis (TGA). All these data confirmed the condensation reactions. However, BET (Brunauer–Emmett–Teller) measurements indicated that the porosity of this material is low. Trapping dyes in solution, as a model of pollutants, by the insoluble porous material 3 has been attempted. Full article

A covalent organic framework (COF) has emerged as a promising photocatalyst for the removal of pharmaceutical and personal care product (PPCP) contaminants; however, high-performance COF photocatalysts are still scarce. In this study, three COF photocatalysts were successfully synthesized by the condensation of benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene-2,5,8-tricarbaldehyde (BTT) with 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)trianiline (TAPT), 1,3,5-Tris(4-aminophenyl)benzene (TAPB), and 4,4′,4′′-nitrilotris(benzenamine) (TAPA), namely, BTT-TAPA, BTT-TAPB, and BTT-TAPT, respectively. The surface areas of BTT-TAPA, BTT-TAPB, and BTT-TAPT were found to be 800.46, 1203.60, and 1413.58 cm²∙g⁻¹, respectively, providing abundant active sites for photocatalytic reactions. Under visible-light irradiation, BTT-TAPT exhibited the highest removal rate of tetracycline (TC), reaching 82.7% after 240 min. The superior photocatalytic performance of BTT-TAPT was attributed to its large specific surface area and the strong electron-acceptor properties of the triazine group. Electron paramagnetic resonance capture experiments and liquid chromatograph mass spectrometer analysis confirmed that superoxide radicals played a pivotal role in the degradation of TC and ciprofloxacin. Moreover, BTT-TAPT exhibited high stability and reproducibility during the photocatalytic degradation process. This study confirms that BTT-based COFs are a class of promising photocatalysts for the degradation of PPCPs in water, and their performance can be further optimized by tuning the structure and composition of the frameworks. Full article

The exploration of heterocyclic compounds and their fused analogs, featuring key pharmacophore fragments like pyridine, thiophene, pyrimidine, and triazine rings, is pivotal in medicinal chemistry. These compounds possess a wide array of biological activities, making them an intriguing area of study. The quest for new neurotropic drugs among derivatives of these heterocycles with pharmacophore groups remains a significant research challenge. The aim of this research work was to develop a synthesis method for new heterocyclic compounds, evaluate their neurotropic and neuroprotective activities, study histological changes, and perform docking analysis. Classical organic synthesis methods were used in the creation of novel heterocyclic systems containing pharmacophore rings. To evaluate the neurotropic activity of these synthesized compounds, a range of biological assays were employed. Docking analysis was conducted using various software packages and methodologies. The neuroprotective activity of compound 13 was tested in seizures with and without pentylenetetrazole (PTZ) administration. Histopathological examinations were performed in different experimental groups in the hippocampus and the entorhinal cortex. As a result of chemical reactions, 16 new, tetra- and pentacyclic heterocyclic compounds were obtained. The biologically studied compounds exhibited protection against PTZ seizures as well as some psychotropic effects. The biological assays evidenced that 13 of the 16 studied compounds showed a high anticonvulsant activity by antagonism with PTZ. The toxicity of the compounds was low. According to the results of the study of psychotropic activity, it was found that the selected compounds have a sedative effect, except compound 13, which exhibited activating behavior and antianxiety effects (especially compound 13). The studied compounds exhibited antidepressant effects, especially compound 13, which is similar to diazepam. Histopathological examination showed that compound 13 produced moderate changes in the brain and exhibited neuroprotective effects in the entorhinal cortex against PTZ-induced damage, reducing gliosis and neuronal loss. Docking studies revealed that out of 16 compounds, 3 compounds bound to the γ-aminobutyric acid type A (GABA_A) receptor. Thus, the selected compounds demonstrated anticonvulsant, sedative, and activating behavior, and at the same time exhibited antianxiety and antidepressant effects. Compound 13 bound to the GABA_A receptor and exhibited antianxiety, antidepressant, and neuroprotective effects in the entorhinal cortex against PTZ-induced changes. Full article

The aims of this study were to determine whether it is possible to use peptide microarrays obtained using the SPOT technique (immobilized on cellulose) and specific polyclonal antibodies to select fragments that reconstruct the outer sphere of proteins and to ascertain whether the selected peptide fragments can be useful in the study of their protein–protein and/or peptide–protein interactions. Using this approach, epidermal growth factor (EGF) fragments responsible for the interaction with the EGF receptor were searched. A library of EGF fragments immobilized on cellulose was obtained using triazine condensing reagents. Experiments on the interactions with EGFR confirmed the high affinity of the selected peptide fragments. Biological tests on cells showed the lack of cytotoxicity of the EGF fragments. Selected EGF fragments can be used in various areas of medicine. Full article

Triazine herbicides are commonly used in agriculture to eliminate weeds. However, they can persist in the environment. In this study, we explored a new method for detecting triazine herbicides in aqueous samples. We selected two triazine herbicides, namely, prometryn and ametryn, as model herbicides. To generate magnetic probes, we mixed aqueous Gd³⁺ with aqueous sodium dodecyl sulfate (SDS), which created magnetic probes made of Gd³⁺-SDS micelles. These probes showed a trapping capacity for the model herbicides. Results indicated that the trapping capacities of our magnetic probes for ametryn and prometryn were approximately 466 and 468 nmol mg⁻¹, respectively. The dissociation constants of our probes toward ametryn and prometryn were 2.92 × 10⁻⁵ and 1.27 × 10⁻⁵, respectively. This is the first report that the developed magnetic probes can be used to trap triazine herbicides. For detection, we used carbon fiber ionization mass spectrometry (CFI-MS), which can be used to directly detect semi-volatiles from the samples in the condensed phase. Because of the semi-volatility of triazine herbicides, the herbicides trapped by the magnetic probes can be directly analyzed by CFI-MS without any elution steps. In addition, we also demonstrated the feasibility of using our approach for detecting triazine herbicides in lake water and drinking water. Full article

Covalent organic frameworks (COFs) have gained considerable attention due to their highly conjugated π-skeletons, rendering them promising candidates for the design of light-emitting materials. In this study, we present two vinylene-linked COFs, namely, VL-COF-1 and VL-COF-2, which were synthesized through the Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with terephthalaldehyde or 4,4′-biphenyldicarboxaldehyde. Both VL-COF-1 and VL-COF-2 exhibited excellent chemical and thermal stability. The presence of vinylene linkages between the constituent building blocks in these COFs resulted in broad excitation and emission properties. Remarkably, the designed VL-COFs demonstrated bright emission, fast fluorescence decay, and high stability, making them highly attractive for optoelectronic applications. To assess the potential of these VL-COFs in practical devices, we fabricated white-light-emitting diodes (WLEDs) coated with VL-COF-1 and VL-COF-2. Notably, the WLEDs coated with VL-COF-1 achieved high-quality white light emission, closely approximating standard white light. The promising performance of VL-COF-coated WLEDs suggests the feasibility of utilizing COF materials for stable and efficient lighting applications. Full article

This work focuses on porous organic polymers (POPs), which have gained significant global attention for their potential in energy storage and carbon dioxide (CO₂) capture. The study introduces the development of two novel porous organic polymers, namely FEC-Mel and FEC-PBDT POPs, constructed using a simple method based on the ferrocene unit (FEC) combined with melamine (Mel) and 6,6′-(1,4-phenylene)bis(1,3,5-triazine-2,4-diamine) (PBDT). The synthesis involved the condensation reaction between ferrocenecarboxaldehyde monomer (FEC-CHO) and the respective aryl amines. Several analytical methods were employed to investigate the physical characteristics, chemical structure, morphology, and potential applications of these porous materials. Through thermogravimetric analysis (TGA), it was observed that both FEC-Mel and FEC-PBDT POPs exhibited exceptional thermal stability. FEC-Mel POP displayed a higher surface area and porosity, measuring 556 m² g⁻¹ and 1.26 cm³ g⁻¹, respectively. These FEC-POPs possess large surface areas, making them promising materials for applications such as supercapacitor (SC) electrodes and gas adsorption. With 82 F g⁻¹ of specific capacitance at 0.5 A g⁻¹, the FEC-PBDT POP electrode has exceptional electrochemical characteristics. In addition, the FEC-Mel POP showed remarkable CO₂ absorption capabilities, with 1.34 and 1.75 mmol g⁻¹ (determined at 298 and 273 K; respectively). The potential of the FEC-POPs created in this work for CO₂ capacity and electrical testing are highlighted by these results. Full article

This paper describes the synthesis of new heterocycles from oxazol-5(4H)-one and 1,2,4-triazin-6(5H)-one classes containing a phenyl-/4-bromophenylsulfonylphenyl moiety. The oxazol-5(4H)-ones were obtained via condensation of 2-(4-(4-X-phenylsulfonyl)benzamido)acetic acids with benzaldehyde/4-fluorobenzaldehyde in acetic anhydride and in the presence of sodium acetate. The reaction of oxazolones with phenylhydrazine, in acetic acid and sodium acetate, yielded the corresponding 1,2,4-triazin-6(5H)-ones. The structures of the compounds were confirmed using spectral (FT-IR, ¹H-NMR, ¹³C-NMR, MS) and elemental analysis. The toxicity of the compounds was evaluated on Daphnia magna Straus crustaceans and on the budding yeast Saccharomyces cerevisiae. The results indicate that both the heterocyclic nucleus and halogen atoms significantly influenced the toxicity against D. magna, with the oxazolones being less toxic than triazinones. The halogen-free oxazolone had the lowest toxicity, and the fluorine-containing triazinone exhibited the highest toxicity. The compounds showed low toxicity against yeast cells, apparently due to the activity of plasma membrane multidrug transporters Pdr5 and Snq2. The predictive analyses indicated an antiproliferative effect as the most probable biological action. The PASS prediction and CHEMBL similarity studies show evidence that the compounds could inhibit certain relevant oncological protein kinases. These results correlated with toxicity assays suggest that halogen-free oxazolone could be a good candidate for future anticancer investigations. Full article

Porous organic polymers (POPs) have plenteous exciting features due to their attractive combination of microporosity with π-conjugation. Nevertheless, electrodes based on their pristine forms suffer from severe poverty of electrical conductivity, precluding their employment within electrochemical appliances. The electrical conductivity of POPs may be significantly improved and their porosity properties could be further customized by direct carbonization. In this study, we successfully prepared a microporous carbon material (Py-PDT POP-600) by the carbonization of Py-PDT POP, which was designed using a condensation reaction between 6,6′-(1,4-phenylene)bis(1,3,5-triazine-2,4-diamine) (PDA-4NH₂) and 4,4′,4′′,4′′′-(pyrene-1,3,6,8-tetrayl)tetrabenzaldehyde (Py-Ph-4CHO) in the presence of dimethyl sulfoxide (DMSO) as a solvent. The obtained Py-PDT POP-600 with a high nitrogen content had a high surface area (up to 314 m² g⁻¹), high pore volume, and good thermal stability based on N₂ adsorption/desorption data and a thermogravimetric analysis (TGA). Owing to the good surface area, the as-prepared Py-PDT POP-600 showed excellent performance in CO₂ uptake (2.7 mmol g⁻¹ at 298 K) and a high specific capacitance of 550 F g⁻¹ at 0.5 A g⁻¹ compared with the pristine Py-PDT POP (0.24 mmol g⁻¹ and 28 F g⁻¹). Full article

Metal free visible light active photocatalysts of covalent organic polymers (COPs) and polymeric graphitic carbon nitride (g-C₃N₄) are interesting porous catalysts that have enormous potential for application in organic pollutant degradation. Imine condensation for COPs, and thermal condensation for g-C₃N₄ were used to produce the catalysts. FT-IR, Raman, NMR, UV-Vis Spectroscopy, X-ray diffraction, and scanning electron microscopy studies were used to investigate the structural, optical, and morphological features of the metal free catalysts. We have constructed COPs with a π-electron deficient (Lewis acidic) triazine core and π -electron rich (Lewis basic) naphthalene and anthraquinone rings coupled by -O and -N donors in this study. Furthermore, the prepared Bulk-g-C₃N₄ (B-GCN) was converted to porous g-C₃N₄ (P-GCN) using a chemical oxidation process, and the generated P-GCN was efficiently mixed with the COP to create a novel nanocomposite for photocatalytic application. Using the anthraquinone-based COP and P-GCN (1:1 ratio, PA-GCN) catalyst, the highest photodegradation efficiencies for the polymeric graphitic carbon nitride of 88.2% and 82.3% were achieved using the Fast green (FG) and Rose bengal (RB) dyes, respectively. The rate constant values of 0.032 and 0.024/min were determined for FG and RB degradation, respectively. Higher activity may be related to the incorporation of COP and PA-GCN, which act significantly well in higher visible light absorption, have superior reactive oxygen generation (ROS), and demonstrate an excellent pollutant–catalyst interaction. Full article

A catalyst-free Schiff base reaction was applied to synthesize two imine-linked covalent organic frameworks (COFs). The condensation reaction of 1,3,5-tris-(4-aminophenyl)triazine (TAPT) with 4,4′-biphenyldicarboxaldehyde led to the structure of HHU-COF-1 (HHU = Heinrich-Heine University). The fluorinated analog HHU-COF-2 was obtained with 2,2′,3,3′,5,5′,6,6′-octafluoro-4,4′-biphenyldicarboxaldehyde. Solid-state NMR, infrared spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis confirmed the successful formation of the two network structures. The crystalline materials are characterized by high Brunauer–Emmett–Teller surface areas of 2352 m²/g for HHU-COF-1 and 1356 m²/g for HHU-COF-2. The products of a larger-scale synthesis were applied to prepare mixed-matrix membranes (MMMs) with the polymer Matrimid. CO₂/CH₄ permeation tests revealed a moderate increase in CO₂ permeability at constant selectivity for HHU-COF-1 as a dispersed phase, whereas application of the fluorinated COF led to a CO₂/CH₄ selectivity increase from 42 for the pure Matrimid membrane to 51 for 8 wt% of HHU-COF-2 and a permeability increase from 6.8 to 13.0 Barrer for the 24 wt% MMM. Full article

In this study six new s-triazine bishydrazino and bishydrazido-based polymers were synthesized via condensation of bishydrazino s-triazine derivatives with terephthaldehyde or via nucleophilic substitution of dichloro-s-triazine derivatives with terephthalic acid hydrazide. The synthesized polymers were characterized by different techniques. The new polymers displayed good thermal behavior with great values in terms of limited oxygen indexed (LOI) 27.50%, 30.12% for polymers 5b,c (bishydrazino-s-triazine based polymers) and 27.23%, 29.86%, 30.85% for polymers 7a–c (bishydrazido-s-triazine based polymers) at 800 °C. Based on the LOI values, these polymers could be classified as flame retardant and self-extinguishing materials. The thermal results also revealed that the type of substituent groups on the triazine core has a considerable impact on their thermal behavior. Accordingly, the prepared polymers were mixed with ammonium polyphosphate (APP) in different proportions to form an intumescent flame-retardant (IFRs) system and were introduced into polypropylene (PP) to improve the flame-retardancy of the composites. The best results were obtained with a mass ratio of APP: 5a–c or 7a–c of 2:1, according to the vertical burning study (UL-94). In addition, the presence of 25% “weight ratio” of IFR in the composite showed great impact and passed UL-94 V-0 and V-1 tests. Full article

On our way to discovering and developing compounds that have an antioxidant impact compared to ascorbic acid and other biological activities, we designed, synthesized, and evaluated a new series of heterocyclic moieties drugs (1–11) as antioxidants and antimicrobial agents. As starting moieties, these new candidates were derived from two promising heterocyclic compounds, imidazoldin-4-one and thiazol-4-one. Firstly, diphenylimidazol 1 was obtained because of the cyclo condensation one-pot ternary reaction of urea, aniline, and chloroacetic acid under thermal conditions. Out of this starting compound, we could design and create new vital rings such as purine and triazine as in compounds 5 and 6, respectively. Secondly, the start thiazole derivative 7 was obtained from the intermolecular cyclization of thiourea, chloroacetic acid, p-nitobezaldehyde in the presence of sodium acetate. We synthesized various derivatives from this second starting compound 7 by being subjected to different reagents such as aniline, phenylenediamine, phenylhydrazine, and barbituric acid to yield 8, 9, 10, and 11, respectively. Using ascorbic acid as the standard compound, the pharmacological testing for antioxidant activity assessment of the produced derivatives was evaluated against ABTS (2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid). Candidate 6 exhibited the best activity as an antioxidant agent compared to ascorbic acid as a reference compound. Moreover, all compounds were evaluated as antimicrobial agents against a series of bacteria and fungi. Among all synthesized compounds, compound 6 achieved high efficiency against two types of fungi and four kinds of bacteria, as Clotrimazole and Ampicillin were used as the reference agents, respectively. All chemical structures of the novel synthesized candidates were unequivocally elucidated and confirmed utilizing spectroscopical and elemental investigations. Full article

Nowadays, the need to reduce plastic waste and scantly biodegradable fossil-based products is of great importance. The use of leather as an alternative to synthetic materials is gaining renewed interest, but it is fundamental that any alternative to plastic-based materials should not generate an additional environmental burden. In the present work, a simple protocol for collagen stabilization mediated by 2-chloro-4,6-diethoxy-1,3,5-triazine (CDET) and a tert-amine has been described. Different tert-amines were tested in combination with CDET in a standard amidation reaction between 2-phenylethylamine and benzoic acid. Best performing condensation systems have been further tested for the cross-linking of both collagen powder and calf hides. The best results were achieved with CDET/NMM giving high-quality leather with improved environmental performances. Full article

Herein, a highly N-rich covalent triazine framework (CTF) is applied as support for a Ru^III complex. The bipyridine sites within the CTF provide excellent anchoring points for the [Ru(acac)₂(CH₃CN)₂]PF₆ complex. The obtained robust Ru^III@bipy-CTF material was applied for the selective tandem aerobic oxidation-Knoevenagel condensation reaction. The presented system shows a high catalytic performance (>80% conversion of alcohols to α, β-unsaturated nitriles) without the use of expensive noble metals. The bipy-CTF not only acts as the catalyst support but also provides the active sites for both aerobic oxidation and Knoevenagel condensation reactions. This work highlights a new perspective for the development of highly efficient and robust heterogeneous catalysts applying CTFs for cascade catalysis. Full article