The present work focused on the screening process of different inorganic oxides and different temperatures for the epoxidation reaction of macaw palm vegetable oil without using solvent, a promising Brazilian biomass that can substitute other vegetable oils (e.g., soybean oil) in technological applications. This oil has an iodine value of 108.48 g of I2 per 100 g being categorized as a semi-dry oil. The epoxidized vegetable oil can be applied in manifold areas in polymer science. The epoxidation reaction here presented avoided organic solvents and organic acids and aimed to produce a greener route using metal oxides or niobium phosphate as a peroxide-activating catalyst. The experimental parameters were maintained as 10 mol% of catalyst loading and a time of 24 h; however, the temperature for some catalysts was changed to improve the epoxide conversion. Experiments were measured by proton nuclear magnetic resonance (1H NMR). Experiments using titanium oxide (TiO2) as a catalyst reached a conversion greater than 84.7%, while experiments using aluminium oxide (Al2O3) or lanthanum oxide (La2O3) achieved conversions of 22.6 and 30.1%, respectively. Furthermore, it was observed that both niobium compounds instantly react with hydrogen peroxide to form peroxy derivatives. solvent e.g., eg e (e.g. applications 10848 108 48 108.4 I semidry semi dry science peroxideactivating activating 1 mol 2 h however 1H H NMR. NMR . NMR) TiO2 TiO (TiO2 847 84 7 84.7% Al2O3 AlO Al O (Al2O3 La2O3 LaO La (La2O3 226 22 6 22. 301 30 30.1% respectively Furthermore derivatives e.g. (e.g 1084 4 108. (TiO 8 84.7 Al2O (Al2O La2O (La2O 3 30.1 e.g 84. 30.

Schiff bases are diverse organic compounds with an azomethine structure (–C=N–), holding potential in both chemistry and biology. They serve as catalysts, stabilizers, and exhibit various biological activities. The molecular structure of Schiff bases influences their biological properties, including antimicrobial effects. Redox-active compounds with more negative potentials tend to be more effective against microbes. In one of our recent studies, we explored the antimicrobial properties of two Schiff bases derivatives, SB-1 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino) and SB-2 ((E)-2-((4-nitrobenzilidene)amino)aniline). SB-1 showed antibacterial activity against certain Gram-positive bacteria, while SB-2 did not. The difference in their cyclic voltametric profiles, especially SB-1’s more negative reduction potential, prompted us to carry out further characterizations, including scan-rate studies, solvent analysis, and computational calculations. We found that SB-1, which presents a stable intramolecular hydrogen bond, undergoes irreversible oxidation, likely at the –NH2 group, and a quasi-reversible reduction via an intramolecular reductive coupling of the (–C=N–) azomethine group, supported by orbital theoretical calculations. This research sheds light on the potential applications of Schiff bases in antimicrobial contexts, guided by their redox properties and structure. –C=N–, CN –C=N– , C N biology catalysts stabilizers activities effects Redoxactive Redox active microbes studies derivatives SB1 SB 1 SB- E4amino33,5ditertbutyl2hydroxybenzylideneamino E4amino335ditertbutyl2hydroxybenzylideneamino Eaminoditertbutylhydroxybenzylideneamino E 4 amino 3 3,5 di tert butyl 2 hydroxybenzylidene 5 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino SB2 E24nitrobenzilideneaminoaniline. E24nitrobenzilideneaminoaniline Enitrobenzilideneaminoaniline nitrobenzilidene aniline . ((E)-2-((4-nitrobenzilidene)amino)aniline) Grampositive Gram positive bacteria not profiles SB1s SBs s characterizations scanrate scan rate analysis calculations SB1, 1, bond oxidation NH2 NH –NH group quasireversible quasi reversible (–C=N– contexts –C=N E4amino33 5ditertbutyl2hydroxybenzylideneamino ditertbutyl hydroxybenzylideneamino 35 3, nitrobenzilideneaminoaniline ((E)-2-((4-nitrobenzilidene)amino)aniline (–C=N Eamino E4amino3 ditertbutylhydroxybenzylideneamino E4amino

This review provides an overview of the recent progress in organic electrosynthesis in Brazil, ranging from 2013 to 2023. By highlighting the principles, applications, and limitations of various electrosynthetic methodologies, this article aims to contribute to the understanding of basic principles and stimulate research in this field in Brazil. Moreover, the limitations and challenges associated with organic electrosynthesis are covered. Factors such as electrode material selection, solvent effects, and reaction optimization are discussed, highlighting the need for further research and development to overcome these obstacles. Finally, future prospects are outlined. Brazil 201 2023 applications methodologies Moreover covered selection effects discussed obstacles Finally outlined 20 202 2

In recent years, the field of coordination chemistry has experienced a surge in interest regarding the synthesis and characterization of coordination complexes for diverse applications. This study is dedicated to investigating coordination compounds resulting from the interaction of nonsteroidal anti-inflammatory drugs (NSAIDs) with metal ions. The study research places significant emphasis on understanding the stability and thermal behavior of these coordination compounds. The utilization of thermoanalytical techniques is crucial in achieving this goal. Thermal analysis and thermokinetics provide valuable insights into the underlying mechanisms, kinetics, and energetics of these reactions, thereby facilitating the optimization of synthesis procedures. The research employs concurrent techniques, namely thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), to explore the thermal stability and decomposition pathways of these coordination compounds. Thermokinetic models and optimization methodologies are subsequently applied to identify key reaction parameters. The primary aim of this research is to unveil the thermal behavior, stability, and reaction kinetics of aceclofenac coordination compounds, thus contributing significantly to the understanding of thermokinetics and thermal analysis in the domain of coordination chemistry. Specifically, this study is focused on aceclofenac coordination complexes involving lanthanum and gadolinium, with the ultimate goal of advancing the field of coordination chemistry. years applications antiinflammatory anti inflammatory NSAIDs (NSAIDs ions mechanisms reactions procedures TG (TG DSC, DSC , (DSC) parameters Specifically gadolinium (DSC

The study of atomic spectroscopy has a profound relationship with quantum mechanics and its comprehension. Since Bohr’s success with a theory for the atom, it has been established that spectrum lines originate from transitions between different states. Moreover, the analysis of complex spectra reveals that there are groups of spectral lines that compose what is called a multiplet. To rationalize the multiplet structure, we need models to characterize and label the quantum states. The characterization of the atomic states is a common subject in classes of physical chemistry and inorganic chemistry, and there are basically two approaches to infer and label the energy states: (i) the LS coupling scheme and (ii) the jj coupling scheme. Usually, only the LS coupling is presented, and this ends up omitting its underlying assumptions. Here, we present a survey of both approaches, highlighting their premises and their adequacy towards different groups of the periodic table, ions, and excited states configurations. We show that by using benchmark data together with the Landé interval rule, the appropriate use of the jj coupling to understand the atomic spectra of heavier atoms is easily conveyed. comprehension Bohrs Bohr s atom Moreover structure i (i ii (ii Usually presented assumptions Here table ions configurations rule conveyed

Alfred Schaeffer (1879-1957) was a German chemist who arrived in Minas Gerais in 1911 hired by the state government to organize the state health service in its newly established capital. He directed the Laboratory of Chemical Analysis of the State, and his analytical methods in dairy and mineral waters became a reference in Brazil. He also became professor of Chemistry at the new Faculty of Medicine of Belo Horizonte and founded the Chemistry Institute of the Engineering School in that city, influencing several students who became important names in Brazilian science. In addition, he was responsible for the assembly and technical coordination of pioneering industries in the dairy and wood distillation sector in the city of Santos Dumont. Later he assumed the post of technical director of Merck, also in Minas Gerais. Moving to Rio de Janeiro, he assumed a chair at the Technical School, working in teaching and research, and remained active even after retiring, publishing in important scientific journals. 18791957 1879 1957 (1879-1957 191 capital State Brazil science addition Dumont Merck Janeiro research retiring journals 1879195 187 195 (1879-195 19 187919 18 (1879-19 1 18791 (1879-1 (1879- (1879 (187 (18 (1 (

Layered double hydroxides (LDHs) and related materials have been studied for a long time and their application in catalytic processes remain attractive due to the tuned properties, morphologies and metal-support interactions obtained from a variety of composition and synthesis route. In this mini-review, some important reactions, such as photocatalysis, electrocatalysis, reduction, carbon-carbon cross-couplings and water-gas shift will be emphasized along with the role of LDHs as catalysts, co-catalysts or catalytic precursors when it was clearly indicated. (LDHs properties metalsupport metal support route minireview, minireview mini review, review mini-review reactions photocatalysis electrocatalysis reduction carboncarbon carbon crosscouplings cross couplings watergas water gas catalysts cocatalysts co indicated

Ana Rosa Kucinski Silva, lecturer in the Department of Chemistry at the University of São Paulo (São Paulo, Brazil), had her academic career violently interrupted in April 1974 when was kidnapped, tortured, and murdered by the repression forces of the military dictatorship (1964-1985). Since then, papers and books were written about her, emphasizing her political activities but much less is known on her academic activities. Fifty years after her disappearance, this work aims to contribute to fill this gap. Silva Brazil, Brazil , Brazil) 197 kidnapped tortured 19641985. 19641985 1964 1985 . (1964-1985) then disappearance gap 19 1964198 196 198 (1964-1985 1 196419 (1964-198 19641 (1964-19 (1964-1 (1964- (1964 (196 (19 (1 (

Chitosan (CS) blends with collagen (CL) and Aloe vera (AV) have gained significant attention in the biomedical field due to their biocompatibility, biodegradability, and potential for wound healing applications. In this study, we investigated the preparation and characterization of CS/CL and CS/AV blends using selective precipitation and co-precipitation techniques. The synthesis processes were analyzed for yield and 4-hydroxyproline content (in CS/CL blends). The materials were characterized using bromatological analyses, viscosity measurements, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). These eco-friendly methods effectively promoted interactions between the biopolymers, resulting in homogeneous blends with tunable properties. Besides, they are simple, fast, safe, and require minimal infrastructure. This study demonstrated that selective precipitation and co-precipitation are effective methods for producing chitosan/collagen and chitosan/Aloe vera blends. These methods foster interactions and miscibility between the biopolymers, as confirmed by FTIR, XRD, viscosity, and 4-Hy content analyses. They also align with green chemistry principles by avoiding organic solvents, reducing environmental risks, and minimizing waste. The high yields achieved, especially for CS/AV blends (exceeding 96%), make these materials compatible with lyophilization procedures. The absence of segregated phases after appropriate washing underscores their suitability for pharmaceutical formulations and other applications. CS (CS CL (CL AV (AV biocompatibility biodegradability applications CSCL CSAV coprecipitation co techniques 4hydroxyproline hydroxyproline 4 . blends) analyses measurements Fouriertransform Fourier transform FTIR , (FTIR) Xray X ray XRD (XRD) SEM. SEM (SEM) ecofriendly eco friendly biopolymers properties Besides simple fast safe infrastructure chitosancollagen chitosan chitosanAloe 4Hy Hy solvents risks waste achieved exceeding 96%, 96 96% 96%) procedures (FTIR (XRD (SEM 9

The focus of this manuscript is to present the extension project “(Re)thinking the (in)differences: the deconstructions and resistance to transversal themes in the teaching of Natural Sciences”, as well as analyzing its potential when working with continued training work by teachers, promoting debate, discussion, and reflection on the use of contemporary cross-cutting themes in chemistry and science classes. It was also intended to stimulate class planning, the production of strategies and teaching material by educators motivated by the need to reform thinking and regenerate teaching, considering social themes that seek the empowerment of groups placed on the margins of the education system, so that they undertake training that is a collective achievement and built with social discussions. Rethinking Re indifferences differences (in)differences Sciences, Sciences , Sciences” teachers debate discussion crosscutting cross cutting classes planning system discussions

In order to extract hesperidin from Citrus aurantium L. through green and efficient ways, a novel method based on deep eutectic solvent (DES) assisted extraction has been developed. Compared to known alkali extraction and acid precipitation or organic solvent (ethanol, methanol) extraction, this new DES system of choline chloride/diethanolamine (DES-14) method exhibited excellent extraction efficiency for hesperidin. Under optimal conditions, the extraction yield of hesperidin reached 6.26 ± 0.05%. Further studies with infrared spectroscopy, 1H nuclear magnetic resonance, and density functional theory showed the DES-14 was formed mainly through the interaction of H-bond and van der Waals forces. In addition, scanning electron microscopy and density functional theory revealed the strong dissolving capacity, and the H-bond formation between DES-14 and hesperidin, as well as van der Waals forces all contributed to efficient extraction of hesperidin. The results provide a new strategy for efficient extraction and utilization of hesperidin in Citrus. L ways (DES developed ethanol, ethanol (ethanol methanol chloridediethanolamine chloride diethanolamine DES14 14 (DES-14 conditions 626 6 26 6.2 005 0 05 0.05% spectroscopy H resonance DES-1 Hbond bond addition capacity DES1 1 (DES-1 62 2 6. 00 0.05 DES- (DES- 0.0 0.

In this study, it was investigated chitosan (CHIT) films in the presence or absence of cellulose nanofibers (CNF) and silver nanoparticles (AgNP), whose chemical interactions involving metallic surfaces were characterized by surface-enhanced Raman scattering (SERS) spectroscopy. Changes in the morphology were analyzed through atomic force microscopy (AFM) and scanning electron microscopy (SEM). SEM and AFM micrographs revealed that the incorporation of CNF significantly altered CHIT films, leading to changes in the polymer topography and surface texture due to intimal interactions between CNF and the CHIT matrix. Raman spectra of CHIT and CNF/CHIT films showed similar profiles, reflecting comparable molecular structures of both modified biopolymers. However, SERS spectra of both films, after recovering with AgNP, demonstrated distinct spectral profiles. Innovatively, density functional theory (DFT) calculations of an oligomer model for CHIT were employed to assign the vibrational modes observed in the SERS spectra, which allowed identify key interactions between CHIT moieties and AgNP surfaces. SERS results revealed that chemical adsorption of CHIT on AgNP surfaces occurs through interactions of glycosidic oxygen and amino groups. Such findings provide insights into the structural and chemical behavior of this nanocomposite, highlighting its potential for advanced biological applications. study (CHIT (CNF , (AgNP) surfaceenhanced enhanced (SERS spectroscopy (AFM SEM. . (SEM) matrix CNFCHIT profiles biopolymers However Innovatively DFT (DFT groups nanocomposite applications (AgNP (SEM

The history of the discovery, use, and development of dyes is closely linked to the history of humanity itself. Among the first records of human civilization are cave paintings made from, e.g., fruits, plants, minerals, and insects. Over the centuries, using different techniques, colors have been given to all types of materials and products, from clothing to food. The chemicals responsible for colors are dyes - a vast collection of molecules of the most varied compositions, but which have in common the absorption of light within the visible window of the electromagnetic spectrum. This article aims not only to review the properties of some classes of natural dyes, their origins, and their applications but also to describe the various computational chemistry methods involved in designing new bio-inspired molecules. discovery use itself eg e g e.g. fruits plants minerals insects centuries techniques products food compositions spectrum origins bioinspired bio inspired e.g

Bulk precipitation (BP) samples were collected at two coastal urban sites and two montane Atlantic Forest (400 and 1000 m altitude) areas in southeastern Brazil from August 2008 to August 2009. These samples were analyzed for the major inorganic ions (H+, Na+, K+, Ca2+, Mg2+, Cl- and SO42-) found in rainwater. The concentrations of inorganic nitrogen species (NH4+, NO3- and NO2-) were compiled from a previous study. The volume-weighted mean (VWM) concentrations of inorganic ions differed spatially, with higher values at the coastal urban and coastal periurban sites. On a molar basis, Cl- and Na+ together comprised 60% of the total inorganic constituents at the coastal urban site and 34-42% at the other three sites, as it is the closest to the ocean. Magnesium was also primarily associated with sea-salt aerosol. Non-sea-salt (nss) fractions of K+, Ca2+ and SO42- comprised 68-93% of their VWM concentrations, indicating the contribution of natural (mostly biogenic) and anthropogenic (SO2 oxidation for the latter) sources. Finally, we found that the acidity of BP at the four sampling sites is primarily controlled by the NH4+, nss-Ca2+, nss-SO42-, and NO3- ions, resulting in VWM pH values ranging from 5.60 (lower montane forest) to 5.98 (coastal periurban site). (BP 400 (40 100 altitude 200 2009 H+, H (H+ Na K K+ Ca2 Ca Mg2 Mg Mg2+ Cl SO42 SO rainwater NH4 NH (NH4+ NO3 NO NO2 NO2- study volumeweighted volume weighted (VWM spatially basis 60 3442% 3442 34 42% 42 34-42 ocean seasalt sea salt aerosol Nonseasalt Non nss (nss 6893% 6893 68 93% 93 68-93 mostly biogenic SO2 (SO latter sources Finally NH4+ nssCa2+, nssCa2 nssCa nss-Ca2+ nssSO42, nssSO42 nssSO , nss-SO42- 560 5 5.6 lower forest 598 98 5.9 site. . site) 40 (4 10 20 H+ (H SO4 (NH4 6 344 3 4 34-4 689 9 68-9 nssCa2+ nss-Ca2 nssSO4 nss-SO42 56 5. 59 ( 1 2 (NH 34- 68- nss-Ca nss-SO4 nss-SO

The ability to argue is essential for the education of students, as it is fundamental to the presentation of ideas on a given topic. Several methods have been proposed in studies that support the development of argumentation in different teaching contexts, such as the heuristic diagram. It allows the organization and recording of activities that enable critical reflection through the analysis of the language used to express ideas. In this perspective, the diagrams produced for solving problems in an experimental chemistry subject offered in an undergraduate chemistry course were analyzed. Toulmin’s argument pattern was used as a basis to identify the structure of the arguments produced, and then, the quality of the arguments was evaluated. The results of the analysis showed a principle of progress in the argumentative capacity of undergraduates with the development of activities, verified by the presence of elements in students’ texts that, when present, validate an argument. Thus, the results can contribute to other researches in the field of chemical education by favoring a teaching process that considers the development of initial argumentative ability in the formation of students. students topic contexts diagram perspective analyzed Toulmins Toulmin s then evaluated present Thus