Doutorado em Química (IQ)

URI Permanente para esta coleçãohttp://200.137.215.59/tede/handle/tde/270

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Thermopred : aplicação de inteligência artificial e química quântica na predição de propriedade termoquímica e espontaneidade de reações de degradação em insumos farmacêuticos ativos
(Universidade Federal de Goiás, 2026-02-27) Santos, Diullio Pereira dos; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Ribeiro, Alany Ingrid; Silva, Alisson Moraes e; Machado, Daniel Scalabrini; Colherinhas, Guilherme; Oliveira, Heibbe Cristhian Benedito de
We developed artificial intelligence models to predict thermodynamic properties associated with the degradation of active pharmaceutical ingredients (APIs), focusing on Gibbs free energy (ΔG) and enthalpy (ΔH), in alignment with RDC No. 964/2025 issued by ANVISA, which reinforces the need for a deeper mechanistic understanding of forced degradation studies. A novel dataset comprising more than 14,000 chemical structures, including APIs and their degradation products, was constructed from the Brazilian DCB list and public databases such as PubChem. Thermodynamic properties were calculated using quantum chemical methods in Gaussian 16 at the M06-2X/6-31G(d) level of theory. Molecular representation was performed using Morgan fingerprints (RDKit), with structural similarity assessed through the Tanimoto coefficient. Thermodynamic variables were normalized to optimize model training and subsequently transformed back to their original scale to preserve physicochemical interpretability. Three machine learning algorithms—XGBoost, Random Forest, and Multilayer Perceptron (MLP)—were evaluated using R², Q², and RMSE as performance metrics. XGBoost achieved the best overall performance (Q² = 0.9947 and RMSE = 0.0137 for ΔG), with internal validation via StratifiedKFold and external validation confirming statistical robustness and strong generalization capability. The results demonstrate the potential of integrating computational chemistry and machine learning as a predictive framework for anticipating critical thermodynamic properties, supporting regulatory decision-making, and advancing data-driven pharmaceutical development strategies.
Desenvolvimento de catalisadores em suporte híbrido e eletrodos de difusão de gás para células a cumbustível de membrana aniônica
(Universidade Federal de Goiás, 2025-12-12) Bastos, Tarso Leandro; Gelamo, Rogério Valentim; http://lattes.cnpq.br/6269182259456067; Colmati Júnior, Flávio; http://lattes.cnpq.br/0231242349462585; Colmati Júnior, Flávio; Alonso, Christian Gonçalves; Giz, Martha Janete; Sousa, Raphael Nagao de; Souza, Felipe de Moura
Embargo
Desenvolvimento de catalisadores em suporte híbrido e eletrodos de difusão de gás para células a combustível de membrana aniônica
(Universidade Federal de Goiás, 2025-12-12) Bastos, Tarso Leandro; Gelamo, Rogério Valentim; http://lattes.cnpq.br/6269182259456067; Colmati Junior, Flavio; http://lattes.cnpq.br/0231242349462585; Colmati Júnior, Flávio; Alonso, Christian Gonçalves; Giz, Martha Janete; Sousa, Raphael Nagao de; Souza, Felipe de Moura
Embargado
Desenvolvimentos de catalisadores de espinélios de cobalto-ferro para oxidação da água
(Universidade Federal de Goiás, 2021-02-05) Magalhães, River Souza; Souza, Aparecido Ribeiro de; http://lattes.cnpq.br/7884708272070266; Souza, Aparecido Ribeiro de; http://lattes.cnpq.br/7884708272070266; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Martins, Felipe Terra; http://lattes.cnpq.br/0466799995060671; Gil, Eric de Souza; http://lattes.cnpq.br/3218622824233303; Oliveira, Sérgio Botelho de; http://lattes.cnpq.br/3447406257464639
Nature efficiently converts solar energy into chemical energy through photosynthesis. Photosynthesis presents a viable solution to the global energy crisis, as it utilizes highly efficient catalysts for this conversion. In this way, it is possible to synthesize catalysts that perform the same function as those in photosynthesis for the oxidative splitting of water. In this work, four cobalt ferrite-based catalysts were synthesized by the modified chemical coprecipitation method and characterized by the following techniques: atomic absorption spectroscopy (AAS) , X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), thermogravimetric analysis (TG/DTA), and electrochemical analysis. Analyses regarding the SBET surface area and particle porosity were related using the Langmuir isotherm. The samples exhibited a surface area ranging from 21 to 148 m2 g -1 and pore sizes varying from 2.6 to 22 nm. The diffractograms of the samples were indexed as the ferrite (CoFe2O4 and FeCo2O4). The sample with the highest cobalt content showed (511) and (440) peaks corresponding to the Co3O4 oxide. The crystallite size ranged from 9 to 55 nm for all synthesized samples. The IR data showed characteristic bands of FeCo2O4 ferrites in the range of 500 to 900 cm-1 . The band at 650 cm-1 was attributed to the vibrations of the tetrahedral sites, corresponding to the MO bonds (M = Co2+), and the band at 518 cm-1 was attributed to the vibrations of the octahedral sites, corresponding to the MO bonds (M = Fe3+ or Co3+). The cobalt and iron ferrites, with diferente Fe3+ and Co2 ion ratios, were catalytically tested for water oxidation. The results obtained through chemical assays and with the Clark-type electrode showed that the ferrite with a molar ratio of [Co] / [Fe] = 2.0 has the highest turnover number (TOF = 346) and turnover frequency (TOF = 7.4 s-1 ). This material was heated at different temperatures to study its structural morphology. It was observed that the heating made the materials more crystalline and less active for water oxidation.
Propriedades fotofísicas de porfirinas monocatiônicas de Pd(II), Pt(II) e Ru(II) e sua interação com a albumina sérica bovina
(Universidade Federal de Goiás, 2025-11-24) Silva, Juliany Naura Marciel da; Gonçalves, Pablo José; http://lattes.cnpq.br/0515343409614452; Gonçalves, Pablo José; http://lattes.cnpq.br/0515343409614452; Kato, Lucilia; http://lattes.cnpq.br/1362891438631386; Duarte, Gabriela Rodrigues Mendes; http://lattes.cnpq.br/9005971441891787; Alonso, Antônio; http://lattes.cnpq.br/5013069863616789; Franchi, Leandro Pereira; http://lattes.cnpq.br/8068976548504815
Porphyrins are stable tetrapyrrole macrocycles with strong absorption in the visible region and high singlet oxygen generation efficiency, well established as photosensitizing agents in Photodynamic Therapy (PDT). Their monocationic derivatives often exhibit interactions with biological targets, although their interactions with albumins are not yet fully understood. In this work, a complete photophysical characterization of a set of monocationic porphyrins (H₂MPyP) and their Pd(II), Pt(II), and Ru(II) complexes was performed. For this purpose, spectroscopic techniques such as UV-vis, Laser Flash Photolysis, and fluorescence and phosphorescence emission were employed, from which parameters such as molar absorption coefficient, quantum yields of triplet state formation, fluorescence, and singlet oxygen were obtained. Furthermore, their interactions with bovine serum albumin (BSA) were investigated, including binding constant and its photo-oxidation under irradiation with a halogen lamp. Compared to tetracationic analogs, the monocationic porphyrins were more efficient in populating the triplet state and generating singlet oxygen. Among them, H₂MPyP, PdMPyP, and PtMPyP exhibited high triplet quantum yields (ΦT ≈ 0.85), with H₂MPyP showing the highest singlet oxygen yield (ΦΔ = 0.70). All compounds promoted BSA photo-oxidation, with the overall efficiency following the order PtMPyP > PdMPyP > H₂MPyP > RuMPyP; notably, PtMPyP exhibited the highest photodegradation rate constant (kpd = 0.286 min⁻¹). Molecular docking localized all porphyrins in site III (subdomain IB), stabilized by hydrophobic and π–cation interactions. No single descriptor (ΦΔ, lipophilicity, or affinity) alone explained the reactivity, supporting the concept of an "exposure–affinity window": effective protein photo-oxidation requires sufficient binding for colocalization with BSA, but also adequate exposure to O₂ near oxidizable residues. These findings demonstrate that metal coordination finely tunes both excited state deactivation and protein oxidation, offering practical guidelines for designing next-generation PDT photosensitizers with enhanced efficiency and selectivity.
Avaliação da eficácia de adsorventes na purificação de biodiesel
(Universidade Federal de Goiás, 2015-12-17) Silva, Marcos Alexandro Abreu e; Antoniosi Filho, Nelson Roberto; http://lattes.cnpq.br/5982964870999454; Nelson Roberto Antoniosi Filho, Nelson Roberto Antoniosi Filho; http://lattes.cnpq.br/5982964870999454; Cavalcanti, Eduardo Homem de Siqueira; http://lattes.cnpq.br/5116658627669572; Prados, Carolina Porto; http://lattes.cnpq.br/8593600765457692; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Leles, Maria Inês Gonçalves; http://lattes.cnpq.br/1614912440064013
Embargada.
SpectraFP e SpectraFP1H: novos descritores espectrais para aplicações em quimioinformática, caracterização molecular e algoritmos de busca
(Universidade Federal de Goiás, 2025-09-12) Silva, Jefferson Richard Dias da; Queiroz Júnior, Luis Henrique Keng; http://lattes.cnpq.br/5071272851467384; Queiroz Júnior, Luiz Henrique Keng; Ferri, Pedro Henrique; Colnago, Luiz Alberto; Vianna, Pollyana Ferreira da Silva; Silva, Alisson Moraes e
Embargado
Desenvolvimento de sensores eletroquímicos/colorimétricos e metodologias analíticas automatizadas em plataforma de microfluídica digital para aplicações em química bioanalítica
(Universidade Federal de Goiás, 2025-02-25) Rocha, Danielly Santos; Coltro, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213; Wendell Karlos Tomazelli; Coltro, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213; Silva, Cecília de Carvalho Castro e; http://lattes.cnpq.br/6889517148629242; Sartori, Elen Julciléia Romão; http://lattes.cnpq.br/4436300782833384; Santhiago, Murilo; http://lattes.cnpq.br/8347859369190075; Santos, Wallans Torres Pio dos; http://lattes.cnpq.br/2088519063183145
Embargada.
Development of quantum methods for invisible catalysts: external electric fields and solvation effects in Hurd–Claisen rearrangements
(Universidade Federal de Goiás, 2025-07-09) Barbosa, Mateus Rodrigues; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Oliveira, Heibbe Cristhian Benedito de; Camargo, Lilian Tatiane Ferreira de Melo; Barbosa, Martin Schwellberger; Pontes, Renato Borges; Paterno, Leonardo Giordano
This work presents the development of computational protocols to investigate the catalytic effects of oriented external electric fields and solvation on the Hurd-Claisen rearrangement. The study integrates density functional theory calculations with sequential Quantum Mechanics / Molecular Mechanics simulations, incorporating the average electrostatic configuration approximation of the solvent together with the free energy gradient approximation. These computational protocols allow for accurate modeling of solvent interactions and fieldinduced perturbations, providing insights into reaction kinetics and stereoselectivity. A key innovation of this research is the Python module MoleKing, developed to automate computational workflows, including molecular geometry manipulation, rotation, and alignment with electric fields. Written in C++, MoleKing streamlines the preparation of quantum chemical calculations by automatically reorienting molecules along the reaction or molecular axes, facilitating the efficient application of electric fields. Furthermore, the module handles input/output file processing for software such as Gaussian and PSI4, significantly reducing manual intervention and computational errors. The developed methodology was applied to a series of Hurd-Claisen rearrangements with different substituents, given the well-known sensitivity of this reaction to electrostatic interactions, systematically evaluating the influence of oriented external electric fields along the reaction and molecular axes. Solvation effects were modeled using ethyl vinyl ether within the Quantum Mechanics / Molecular Mechanics Sequential framework, revealing the interaction between the solvent and external fields in modulating dipole moments and transition state geometries. Computational simulations demonstrate that external fields can significantly alter stereoselectivity by selectively stabilizing specific transition states, while solvation introduces non-negligible polarization effects that influence activation barriers. These findings highlight the potential of invisible catalysis as a precise tool for stereochemical control.
Fixação química de CO2 em epóxidos para a produção de carbonatos cíclicos utilizando-se catalisadores metaloporfirínicos
(Universidade Federal de Goiás, 2024-06-27) Mata, Álvaro Farias Arruda da; Martins, Dayse Carvalho da Silva; http://lattes.cnpq.br/3157693434749669; Rafael Pavão Das Chagas, Rafael Pavão Das Chagas; http://lattes.cnpq.br/9712618482518275; Chagas, Rafael Pavão das; http://lattes.cnpq.br/9712618482518275; Oliveira, Cecília Maria Alves de; http://lattes.cnpq.br/3152041311943092; Batista, Alzir Azevedo; http://lattes.cnpq.br/6469642481998660; Silva Filho, Juvenal Carolino da; http://lattes.cnpq.br/1223323473808888; Andrade, Fabiano Molinos de; http://lattes.cnpq.br/8880807687863294
Growing concern over significant increases in anthropogenic carbon dioxide (CO2) levels in the atmosphere, along with the dependence on finite fossil carbon resources for the production of high-value-added molecules, has driven research into the catalytic conversion of CO2. CO2 data from the Mauna Loa Observatory, an atmospheric reference station located in Hawaii, show rising monthly concentrations, reaching about 421 ppm in 2023, with projections of 450 ppm by 2030 and 540-970 ppm in the next century. Although CO2 is used in various sectors of the chemical industry, its application in fine chemistry is limited, indicating the need to explore technologies for its sustainable utilization. CO2 is considered a promising carbon source due to its abundance, renewability, and economic accessibility. Recent research has focused on its conversion into high-value-added products such as alcohols, amines, carboxylic acids, and carbonates. Replacing phosgene with CO2 in the synthesis of organic carbonates represents a significant advance, not only economically but also environmentally. The cycloaddition reaction between CO2 and epoxides to form cyclic carbonates is a process of interest, with various industrial applications. Metal catalysts with porphyrinic ligands have demonstrated efficiency in this process, standing out due to their high activity and selectivity. Macrocyclic ligands, such as porphyrins, have been widely investigated due to their versatility and robustness, proving promising for this application. In this study, the synthesis of six metalloporphyrin complexes and the selective production of cyclic carbonates through cycloaddition reactions between CO2 and epoxides are presented. A theoretical kinetic study was conducted, enabling the determination of an activation energy of 39.76 KJ mol-1 and the thermodynamic parameters in the intermediate states of the cycloaddition reaction of CO2 and styrene oxide. High-resolution mass spectrometry allowed the determination of the activation intermediate of the CO2 cycloaddition, where two styrene oxide molecules are simultaneously activated by one catalyst molecule. Catalysts based on porphyrins, coordinated with metals such as zinc, manganese, and copper, showed efficacy in this process. The continuous development of efficient catalysts and IV the understanding of the mechanisms involved are essential to advance the catalytic conversion of CO2 into high-value-added products
Peptideos antimicrobianos IDR 1002 e TS-MAP1: Ressonância Magnética Nuclear para determinação das estruturas tridimensionais
(Universidade Federal de Goiás, 2024-12-17) Mundim, Higor de Moraes; Lião, Luciano Morais; http://lattes.cnpq.br/2647529909397336; Lião, Luciano Morais; http://lattes.cnpq.br/2647529909397336; Bataus, Luiz Artur Mendes; http://lattes.cnpq.br/5637230378599476; Campos, Ivan Torres Nicolau de; http://lattes.cnpq.br/5450204304438682; Apparecido, Rafael do Prado; http://lattes.cnpq.br/8919390126756314; Santos Neto, José Sebastião dos; http://lattes.cnpq.br/5538841038654451
Embargado
Compostos de coordenação com um ligante do tipo oxamato derivado do ácido 4-aminobenzóico: Síntese, Caracterização e estudo das propriedades ópticas e magnéticas
(Universidade Federal de Goiás, 2024-12-01) Maciel, Jhonny Willians de Oliveira; Gomes, Danielle Cangussu de Castro; http://lattes.cnpq.br/5709288358367849; Gomes, Danielle Cangussu de Castro; Silva, Hermínia Veridiana dos Santos Pessoni e; Ferreira, Leonildo Alves; Gonçalves, Pablo José; Simão, Tatiana Renata Gomes
In this work, we present the syntheses, characterizations, and studies of the optical and magnetic properties of various novel coordination compounds. We obtained supramolecular systems based on complexes with the ligand Sodium 4- (carboxylatoformamido)benzoate (Na2Hpcpa) and the heavy metal ions Cd2+ and Pb2+, as well as a series of isostructural complexes containing the rare earth metal ions Y3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, and Yb3+. The studies of the optical properties of the Cd2+ and Pb2+ compounds show a shift in the emission band position towards white light when compared to the matrix's emission. The Eu3+ and Tb3+ compounds exhibit red and green emissions, respectively, with high thermal stability over the entire temperature range studied, between 16 and 300 K. The external quantum yield for the Tb3+ compound was considerably improved compared to compounds containing oxamate-type ligands reported in the literature, indicating that the ligand Hpcpa2- may be an efficient sensitizer for energy transfer through the so-called antenna effect to Tb3+ ions. Magnetic properties studies of the Eu3+, Gd3+ , Tb3+, and Er3+ compounds were conducted, and ac susceptibility measurements reveal that the Gd3+, Tb3+, and Er3+ compounds exhibit slow relaxation of magnetization induced by the magnetic field, thus representing new examples of field-induced single-molecule magnets (SMMs). Despite the Y3+, Eu3+, Ho3+, Er3+, and Yb3+ compounds not having well-defined single-crystal X-ray diffraction structures, other structural characterizations indicate that all rare earth Ln3+ compounds obtained in this work are isostructural to the Eu3+, Gd3+, and Tb3+ compounds with defined structures. Therefore, among the compounds obtained in this work, the Tb3+ compound can be classified as multifunctional with possible dual technological applications, optical and magnetic.
Estudos da síntese e crescimento de carbonatos de cálcio e magnésio sintéticos
(Universidade Federal de Goiás, 2024-11-29) Pimentel, Hannah Larissa Siqueira Matos; Oliveira, Cecilia Maria Alves de; Carvalho, Jesiel Freitas; http://lattes.cnpq.br/5841291496427516; Carvalho; Martins, Felipe Terra; Leles, Maria Inês Gonçalves; Buifaçal, Leandro Felix de Souza; Neto, Jose de Araujo Nogueira
Embargado.
Uso de terapia fotodinâmica antimicrobiana para o tratamento de Klebsiella pneumoniae produtora de carbapenemase (KPC-Kp)
(Universidade Federal de Goiás, 2025-03-28) Freitas, Alysson Benite de; Souza, Guilherme Rocha Lino de; http://lattes.cnpq.br/1127532567066692; Gonçalves, Pablo José; http://lattes.cnpq.br/0515343409614452; Gonçalves, Pablo José; Bailão, Elisa Flávia Luiz Cardoso; Chagas, Rafael Pavão das; Iglesias, Bernardo Almeida; Chaves, Andréa Rodrigues
Embargado
Síntese de selanil-(hetero)arenos via selenilação da ligação C(sp2)-H promovida por Ácido Tricloroisocianúrico (TCCA)
(Universidade Federal de Goiás, 2025-02-03) Granja, Isis Juliane Arantes; Saba, Sumbal; http://lattes.cnpq.br/0113770075520231; Saba, Sumbal; Silva, Fabiana Ourique da; Barbosa, Martin Schwellberger; Alisson Rodrigues Rosário, Alisson Rodrigues Rosário; Goncalves, Pablo Jose
This thesis proposes a sustainable and efficient methodology for the direct selenylation of (hetero)arenes via selective C(sp2)-H bond functionalization, usmg trichloroisocyanuric acid (TCCA) as an oxidizing agent. The goal was to develop a synthetic strategy that eliminates the need for metal catalysts and toxic solvents, aligning with Green Chemistry principies. The methodology involved mild reaction conditions, employing TCCA as the oxidant and ethanol as a green solvent. Various reaction conditions were explored to optimize the selective introduction of organoselenium groups into N-heteroarenes such as imidazo[l,2-a]pyridine, imidazo[2, 1-b ]thiazole, and indole. The experiments yielded impressive results, ranging from 39% to 97%, with an average of 75%. Mechanistic investigations revealed two main pathways for functionalization, with the electrophilic activation of diselenides proving to be the most efficient. The results highlight the methodology's high selectivity and broad functional group tolerance, setting it apart from traditional approaches. Additionally, this strategy enables efficient functionalization of aromatic and heterocyclic substrates without the need for directing groups or metal catalysts, expanding its synthetic scope. The versatility of this approach opens new possibilities for future research in organic chemistry, including the selective modification of 1tconjugated systems and the construction of novel molecular structures. Overall, the findings reinforce the importance of sustainable chemistry in the synthesis of organochalcogen compounds, providing an efficient and environmentally friendly method for obtaining selenylated derivatives with potential applications across various fields of organic chemistry.
Development of disposable microfluidic devices for bioanalytical applications
(Universidade Federal de Goiás, 2024-11-21) Mendes, Geovana de Melo; Duarte, Gabriela Rodrigues Mendes; http://lattes.cnpq.br/9005971441891787; Varenne, Anne; Duarte, Doutora Gabriela Rodrigues Mendes; Coltro, Wendell Karlos Tomazelli; Silva, José Alberto Fracassi da; Varenne, Anne; Lunte, Susan
This thesis was conducted as part of a joint supervision between the Universidade Federal de Goiás (Goiânia, Brazil) and Chimie ParisTech PSL. Initiated in Brazil at the onset of the pandemic, the work developed during the Ph.D. at the Brazilian institution focused on developing LAMP-based methodologies for COVID-19 diagnosis. Loop-mediated isothermal amplification (RT-LAMP) was used to create a simple and low-cost test during the COVID-19 pandemic. This test was implemented at the point of care in an overwhelmed hospital where standard tests were not feasible, providing rapid and accurate diagnoses. Additionally, we proposed a non-invasive tracking method based on RNA extracted from the saliva of essential workers during the pandemic, which proved practical and effective for frequent testing. The preliminary transposition of this methodology to a paper-based platform showed promising results for realtime monitoring of infections, particularly SARS-CoV-2, at the point of care. Within the scope of the cotutella, subsequent work was carried out in the French laboratory to develop and optimize a paper-based platform for protein isoelectric focusing, aiming to integrate proteomic analysis steps into a microdevice. In this thesis, we developed diagnostic systems for biomolecules applied or applicable at the point of care. For protein analysis, isoelectric focusing on a paper-based platform allowed precise and reproducible protein separation, including in real samples, with acceptable resolution and efficiency. This system represents a significant step forward in a broader project aimed at integrating all proteomic steps into a single chip. The successful development of biomolecule analysis methods prioritizing cost-effectiveness, speed, and simplicity highlights the potential of paper as a platform for these diagnostic tests. Paper proved to be a suitable and accessible platform for conducting these tests, emphasizing its potential in resource-limited settings.
Dispositivos sob demanda: desenvolvimento de sistemas microfluídicos e sensores eletroquímicos por impressão 3D
(Universidade Federal de Goiás, 2020-11-30) Duarte, Lucas da Costa; Coltro, Wendell Karlos Tomazelli; http://lattes.cnpq.br/8302650734477213; Coltro, Wendell Karlos Tomazelli; Lago, Claudimir Lucio do; Muñoz, Rodrigo Alejandro Abarza; Bonacin, Juliano Alves; Vaz, Boniek Gontijo
3D printing technology has been widely explored as an alternative method of manufacturing analytical microdevices. This technology has been solving many limitations of conventional microfabrication techniques due to its ability to build microstructures with different materials and geometries in a simple, fast and low-cost way. In this sense, this thesis describes the use of 3D printing to manufacture analytical platforms for applications involving counting E. coli cells embedded in droplets based on contactless conductometric detection (C4D), online monitoring of chemical reactions by mass spectrometry (MS) and estradiol detection in electrochemical analysis. For C4D measurements, microfluidic devices were printed containing Tjunction microchannels and two electrodes integrated in the antiparallel arrangement. The droplets with incorporated cells were monitored in real time using the C4D system. The proposed approach demonstrated the ability to detect E. coli cells in the concentration range between 86.5 and 8650 CFU droplet-1 with a detection limit of 63.66 CFU droplet-1. For the development of the miniaturized reactor used in the monitoring of chemical reactions by MS, a microfluidic device was built containing a channel in the shape of a 3D serpentine and another one containing a channel in the Y-shaped. Both devices were evaluated for monitoring the Katritzky reaction, injecting simultaneously 2,4,6-triphenylpriryllium (TPP) and amino acid (glycine or alanine) solutions and the reaction product were monitored online by MS at different flow rates. The acquired spectra demonstrated that the relative abundances of the products obtained with the device containing the 3D serpentine channel had an order of magnitude up to three times greater than those obtained with the Y-shaped device. The device performance in 3D serpentine was also evaluated comparing with the traditional ESI(+)-MS technique. The 3D serpentine printed reactor promoted the reaction quickly and with a higher rate of product formation compared to the ESI(+)- MS technique. The electrochemical cell containing integrated electrodes was entirely manufactured by 3D printing. The electrochemical device was manufactured in a single step with a manufacturing time of 12 min and a cost of US$ 0.08. Preliminary tests for the detection of 17β - estradiol by DPV reached an LOD of 0.1 μmol L-1 and an analytical curve with a linear range of 0.19 to 25 μmol L-1. These results demonstrate the excellent versatility of 3D printing technology being applied in different areas of bioanalytical chemistry. The counting method of counting bacteria, the device for online monitoring of chemical reactions, as well as the electrochemical cell for detection of hormones offer instrumental simplicity, low cost, high sensitivity, allowing the opening of new application possibilities in different areas of chemistry.
As Licenciaturas em Química EaD nos IF e a Heutagogia como elemento basilar nos modelos de formação docente
(Universidade Federal de Goiás, 2024-08-27) Alves, Dylan Ávila; Mesquita , Nyuara Araújo da Silva; http://lattes.cnpq.br/6971106875143413; Mesquita , Nyuara Araújo da Silva; Cassiano, Karla Ferreira Dias; Lima, Daniela Da Costa Britto Pereira; Soares, Marlon Herbert Flora Barbosa; Silva Filho, Juvenal Carolino Da
This research aims to investigate the educational methodologies present in distance Chemistry Licentiate courses (LQ). It utilizes the theoretical perspectives of adult education in distance courses (Heutagogy) proposed by Stewart Hase and Chris Kenyon. The goal is to contribute to the discussion of the methodologies used in distance Chemistry courses at Federal Institutes (IF) that facilitate the learning process in these courses. The doctoral thesis was structured from chapters in the format of articles. For the conclusion of the thesis, three chapters/articles were developed titled: 1- Tensions in the Landscape of Chemistry Licentiate Programs in Brazil: Distance Education in Public and Private Spheres; 2- Heutagogy as a Methodology for Teacher Training at a Distance: An Overview of Brazilian Research; 3- An Analysis of Distance Chemistry Licentiate Programs in Federal Institutes from the Perspective of Heutagogical Learning Design Elements. Chapter 1 presents results from the survey of distance Chemistry Licentiate programs (LQ) in public and private higher education institutions (IES) in 2021, conducted through the e-MEC portal. A descriptive study with a quantitative-qualitative approach was used. The distance LQ programs represent a total of 20 courses in public institutions and 25 in private ones. The study highlights a trend towards teacher training through distance education, especially in private IES, but it also indicates the need for public institutions to investigate distance education training. Chapter 2 presents a survey of the main publications related to the Heutagogy theme in the Database of Theses and Dissertations (BDTD) from CAPES and in Portuguese journals. The research is configured as the "state of the art," divided into two moments: the first addresses the inventory of publications from 2010 to 2022, and the second identifies the trends in the publications regarding the theme. A total of 14 publications were surveyed, including five in the BDTD and nine in scientific articles. Initially, an analysis category was established as "Teacher Training," but two categories emerged: Distance Education and Heutagogy as a methodology. The study shows that there is no clear direction in research towards teacher training courses, but it presents Heutagogy as a potential theoretical reference in distance Licentiate courses. Chapter 3 analyzes the curricular proposals (PPC) of distance LQ courses in IF, based on the six learning elements proposed by Blaschke and Hase (2016). It was possible to reveal that the LQ programs present some learning elements in the documents, which can be evidenced in disciplines, evaluation criteria, supervised internships, curricular components, tutorial activities, among others.
Análise computacional da solvatação do diclofenaco e interações da melatonina com radical hidroxila: abordagens via dinâmica molecular e teoria do funcional da densidade
(Universidade Federal de Goiás, 2024-11-14) Rodrigues, Allane Catharina Carvalhaes; Oliveira, Heibbe Cristhian Benedito de; http://lattes.cnpq.br/5995553993631378; Oliveira, Heibbe Cristhian Benedito de; Perez, Caridad Noda; Borges, Leonardo Luiz; Gargano, Ricardo; Lima, Igo Torres
Computational chemistry represents an understanding of chemistry as the manifestation of the behavior of atoms and molecules. This active research field, spanning over a decade, employs mathematical techniques and algorithms to model and simulate chemical influences. The application of computational chemistry is crucial in material design, drug development, and the comprehension of biological processes. Analyzing solute-solvent interactions underscores the importance of physicochemical properties in chemical research, whereas the investigation of free radical elimination is essential for physiological balance. Within this context, the proposed study aims to comprehend the mechanisms of hydroxyl radical removal by melatonin and evaluate the aqueous solvation process of diclofenac through molecular modeling, employing Car-Parrinello and Born-Oppenheimer molecular dynamics, in addition to Density Functional Theory. Results from the dynamics of reactions between the •OH radical and melatonin provide a detailed understanding of various involved conditions, emphasizing the crucial influence of variables such as speed, temperature, and attack direction. The reaction with the hydrogen bonded to the nitrogen of the indole group (called H22) is the more favorable. Energy profiles and rate constants support H22 as the most likely path, providing comprehensive insights into the kinetic and thermodynamic characteristics of the interactions. Our findings regarding diclofenac solubility in water highlight the formation of important intermolecular hydrogen bonds between the atoms of diclofenac with water molecules (OH⋯Owater and CO⋯Hwater). The OH⋯Owater bond is exceptionally strong, similar a covalent bond. Additionally, we observe intramolecular hydrogen bonds in the diclofenac molecule (NH⋯OH e NH⋯Cl) and weaker interactions involving CH⋯Cl. Remarkably, diclofenac protonation contributes to molecular rigidity, hindering future hydrogen bonds with adjacent water molecules, directly impacting molecule solubility. Advancements in this field promise to enrich fundamental chemistry understanding and drive practical advancements in various areas, such as pharmacology, molecular biology, and industrial chemistry.
Aplicação da tecnologia supercrítica no tratamento de resíduos plásticos presentes em amostras de água
(Universidade Federal de Goiás, 2023-12-21) Viana , Júlio Cezar Vieira; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Alonso, Christian Gonçalves; Montel, Adão Lincon Bezerra; Silva, Donizete Xavier da; Oliveira, Heibbe Cristhian Benedito de; Brito, Nubia Natalia de
Phthalic acid esters (PAEs) and bisphenol A (BPA) are plastic waste classified as emerging organic contaminants that can harm biota and human health. These residues arise as a result of the fragmentation of plastics into their monomers or the leaching of compounds used as plasticizers, such as BPA and DEP. In addition to contaminants of emerging concern, these compounds are also classified as endocrine disruptors (EDCs), interacting with estrogen receptors and causing harm to human health and the environment. Even with the availability of physical and chemical wastewater treatment methods, classical treatment methods for these compounds have proven not to be efficient in removing these refractory compounds. Therefore, the objective of this work was to use supercritical water oxidation (OASC) technology to investigate the degradation of BPA and DEP plastic waste in aqueous samples. The variables flow rate, temperature, concentration of oxidizing agent (H2O2) and homogeneous and heterogeneous catalyst, such as Cu(NO3)2 and metallic copper wire, respectively were used as parameters for the tests. Metallic copper was also used in the form of a wire together with H2O2. After treatment using OASC Total organic carbon (TOC) removal efficiencies were found to increase linearly with increasing temperature in the range of 400°C to 700°C for all tests with BPA and DEP. For all tests carried out, the best efficiency in removing total organic carbon (TOC) for BPA was achieved at a temperature of 700°C, oxidant concentration of 60 mM and flow rate of 10 mL.min-1 , reaching 91% of removal. For DEP, the best removal efficiency was achieved at a temperature of 700°C, oxidant concentration of 23 mM and flow rate of 10 mL.min-1, achieving 85% removal. Gas chromatography analysis was carried out for the gaseous components and revealed the presence of hydrogen, carbon dioxide, ethane, ethylene, methane and carbon monoxide gases. The analysis of the liquid fraction for BPA samples in the best treatment condition was carried out using liquid chromatography coupled to mass spectrometry and revealed the presence of the intermediate 2-phenyl2-propanol as the main degradation product. The liquid fraction for DEP samples in the best treatment condition was performed by gas chromatography coupled to mass spectrometry and revealed the presence of aliphatic chain hydrocarbons, such as decosane, triacontane, tetracosane and eicosane as the main degradation products. Therefore, the use of supercritical technology proved to be an efficient method for treating aqueous samples containing BPA and DEP.

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