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193 results on '"Cuin, Alexandre"'

1. Antibacterial profile and antiproliferative activities over human tumor cells of new silver(I) complexes containing two distinct trifluoromethyl uracil isomers

Author

de Menezes Pereira, Gabriele, Bormio Nunes, Julia H., Macedo, Vinicius Souza, Pereira, Douglas Henrique, Buglio, Kaio Eduardo, Affonso, Daniele D., Ruiz, Ana Lucia T.G., de Carvalho, João Ernesto, Frajácomo, Silmara Cristina L., Lustri, Wilton R., Lima, Carmen Silvia Passos, Bergamini, Fernando R.G., Cuin, Alexandre, Masciocchi, Norberto, and Corbi, Pedro Paulo

Published
2025
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11. Pulsed‐Laser‐Driven CO2 Reduction Reaction for the Control of the Photoluminescence Quantum Yield of Organometallic Gold Nanocomposites.

Author

Tahir, Concas, Guilherme C., Gisbert, Mariana, Cremona, Marco, Lazaro, Fernando, Maia da Costa, Marcelo Eduardo H., De Barros, Suellen D. T., Aucélio, Ricardo Q., Pierre, Tatiana Saint, Godoy, José Marcus, Mendes, Diogo, Mariotto, Gino, Daldosso, Nicola, Enrichi, Francesco, Cuin, Alexandre, Ferreira, Aldebarã F., de Azevedo, Walter M., Perez, Geronimo, SantAnna, Celso, and Archanjo, Braulio Soares

Subjects
COLLOIDAL gold, SOLID-state lasers, PHOTOLUMINESCENCE, NANOCOMPOSITE materials, PULSED lasers, PHOTOLUMINESCENT polymers
Abstract

Over the last decade, the CO2 reduction reaction (CO2RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO2 fixation in nanoparticle systems have been demonstrated. Herein, CO2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO2 derivatives in alkaline water environment leads to C2 and C3 coupling with the production of carboxylic acids as a typical CO2RR fingerprint. While laser processing of preformed gold colloids is selective for C2 coupling, both C2 and C3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale. [ABSTRACT FROM AUTHOR]

Published
2024
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35. Correction to "Pulsed‐Laser‐Driven CO2 Reduction Reaction for the Control of the Photoluminescence Quantum Yield of Organometallic Gold Nanocomposites".

Author

Tahir, Concas, Guilherme C., Gisbert, Mariana, Cremona, Marco, Lazaro, Fernando, Maia da Costa, Marcelo Eduardo H., Barros, Suellen D. T. De, Aucélio, Ricardo Q., Pierre, Tatiana Saint, Godoy, José Marcus, Mendes, Diogo, Mariotto, Gino, Daldosso, Nicola, Enrichi, Francesco, Cuin, Alexandre, Ferreira, Aldebarã F., Azevedo, Walter M. de, Perez, Geronimo, SantAnna, Celso, and Archanjo, Braulio Soares

Subjects
PULSED lasers, LASER ablation, DEIONIZATION of water, ION exchange chromatography, GOLD nanoparticles
Abstract

The article "Correction to 'Pulsed-Laser-Driven CO2 Reduction Reaction for the Control of the Photoluminescence Quantum Yield of Organometallic Gold Nanocomposites'" in Small Science addresses errors in the Supporting Information section related to the Pulsed Laser Ablation process and ion chromatography. The correction clarifies the procedures for the PLAL and fragmentation processes, as well as the average TC values for the samples. The authors, a diverse group of researchers, apologize for the inaccuracies in the original text. [Extracted from the article]

Published
2025
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36. MII (M = Mn, Fe, Co, Ni and Cu) complexes with a chromone-derived neutral ligand: synthesis, structural characterization, photocatalytic and mycobacterial activity studies

Author

Camargo, Mariana Leticia Munin, primary, Schwalm, Cristiane Storck, additional, Bortolotto, Tanize, additional, de Freitas Daudt, Natália, additional, Rossi, Grazielle Guidolin, additional, Anraku de Campos, Marli Matiko, additional, D’Oliveira, Kaique Alexandre, additional, Cuin, Alexandre, additional, and Schwade, Vânia Denise, additional

Published
2022
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37. Competition between humic substances and a-amino acids by metal species

Author

Santos Ademir dos, Bellin Iramaia C., Corbi Pedro Paulo, Cuin Alexandre, Rosa André Henrique, Rezende Maria Olimpia de O., Rocha Julio Cesar, and Melnikov Petr

Subjects
humic substances, soils, metals, alpha-amino acids, Chemistry, QD1-999
Abstract

The aim of the present work was to carry out experimental comparison between humic substances (HS) and representative alpha-amino acids (methionine, methionine sulfoxide and cysteine hydrochloride) in relation to the complexation of biologically active trace elements (Al, Cu, Pb, Mn, Zn, Cd and Ni). A mobile time-controlled tangential-flow UF technique was applied to differentiate between HS-metal and alpha-aminoacids-metal complexes. Metal determinations were conventionally carried out using a ICP-OES. The results showed that HS may be considered as a selective complexing agents with higher metal bonding capability in relation to Al, Cu and Pb, the fact that may be clinically important.

Published
2004

42. MII (M = Mn, Fe, Co, Ni and Cu) complexes with a chromone-derived neutral ligand: synthesis, structural characterization, photocatalytic and mycobacterial activity studies.

Author

Camargo, Mariana Leticia Munin, Schwalm, Cristiane Storck, Bortolotto, Tanize, de Freitas Daudt, Natália, Rossi, Grazielle Guidolin, Anraku de Campos, Marli Matiko, D'Oliveira, Kaique Alexandre, Cuin, Alexandre, and Schwade, VÃnia Denise

Subjects
PHOTOCATALYSTS, X-ray powder diffraction, TRANSITION metal complexes, BAND gaps, SOLID solutions, HYDROGEN production, COORDINATION compounds, REFLECTANCE spectroscopy
Abstract

The reaction of 2-(2-furyl)-3-hydroxychromone and nicotinoyl chloride produces a neutral ligand (L), which has nitrogen and oxygen donor atoms. Evidence of L polymorphism is discussed. The new molecule showed fluorescence emission in solution and in the solid state (intense emission at 556 nm [λexc 392 nm] in the solid state). Ligand L and coordination compounds [MCl2(L)2]n (M = Mn (1), Fe (2), Co (3), Ni (4) and Cu (5)) and [Cu(NCS)2(L)2]n (6) were characterized using spectroscopic techniques. The crystal structures were determined via single-crystal X-ray diffraction and powder X-ray diffraction. Biological tests with mycobacterial strains were conducted for compounds 1–5. The optical band gap energies of these compounds, which ranged from 3.29 to 3.39 eV, were estimated from diffuse reflectance spectroscopy data. Mesoporous TiO2-based photocatalysts were prepared and tested for hydrogen production. The m-TiO2-5 photocatalyst produced hydrogen at a 1052.5 μmol g−1 h−1 rate under irradiation using a 300 W Hg/Xe lamp. [ABSTRACT FROM AUTHOR]

Published
2022
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45. A Silver Complex with Cycloserine: Synthesis, Spectroscopic Characterization, Crystal Structure and In Vitro Biological Studies

Author

Ciol, Mariana Rosolen, primary, Manzano, Carlos Marrote, additional, Cuin, Alexandre, additional, Pavan, Fernando Rogério, additional, Ribeiro, Camila Maríngolo, additional, Ruiz, Ana Lúcia Tasca Gois, additional, de Oliveira, Ellen Cristina S., additional, Lustri, Wilton Rogério, additional, Fregonezi, Nathália Ferreira, additional, Nogueira, Flávia Aparecida Resende, additional, and Corbi, Pedro P., additional

Published
2018
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47. New Class of Organic Hole-Transporting Materials Based on Xanthene Derivatives for Organic Electronic Applications

Author

Martins, Jefferson S., primary, Bartolomeu, Aloisio A., additional, dos Santos, Willian Henrique, additional, da Silva Filho, Luiz Carlos, additional, de Oliveira, Eliezer Fernando, additional, Lavarda, Francisco Carlos, additional, Cuin, Alexandre, additional, Legnani, Cristiano, additional, Maciel, Indhira O., additional, Fragneaud, Benjamin, additional, and Quirino, Welber G., additional

Published
2017
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50. Síntese, estrutura e propriedades de complexos de molibdênio, prata e chumbo com ácido 'alfa'-hidroxicarboxílicos

Author

Cuin, Alexandre [UNESP], Universidade Estadual Paulista (Unesp), and Massabni, Antonio Carlos [UNESP]

Subjects
Molybdenum, Silver, Bioinorgânica, Prata, Plumb, Chumbo, Química inorgânica
Abstract

Made available in DSpace on 2014-06-11T19:35:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-10-22Bitstream added on 2014-06-13T19:44:56Z : No. of bitstreams: 1 cuin_a_dr_araiq.pdf: 4874246 bytes, checksum: d2682f8e4635d9604b952790ce19f2ee (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O presente trabalho tem como objetivo o estudo de complexos obtidos a partir da interação de ácidos a-hidroxicarboxílicos ou de seus respectivos sais, com óxidos de molibdênio e de chumbo e com o nitrato de prata. Os ácidos a-hidroxicarboxílicos utilizados foram os ácidos glicólico (C2H4O3), málico (C4H6O5), tartárico (C4H6O6) e mandélico (C8H8O3). Foram sintetizados treze compostos, sendo seis com o íon Mo(VI), quatro com o íon Ag(I) e três com o íon Pb(II). Além destes compostos, foram repreparados três compostos, (NH4)2[MoO2(C2H2O3)2]H2O, (NH4)2[MoO2(C8H6O3)2] e (NH4)2[MoO3(C4H4O6)] H2O. A partir destes três complexos foram obtidos óxidos (MoO3) com áreas superficiais entre 1,0 e 3,0 m2/g. Cinco compostos da série M2[MoO2(C2H2O3)2]nH2O, onde M = Li+, Na+, K+, Rb+ e Cs+; C2H2O3 2- = glicolato2- e n = 1 ou u, foram preparados a partir da adição de MoO3(s) em solução do sal alcalino desejado do ácido glicólico na proporção molar metal:ligante 1:2. Os compostos no estado sólido foram separados da solução por filtração após concentração e adição de etanol absoluto. Os compostos foram caracterizados por análise elementar, espectroscopia IV e difratometria de raios X. Foi realizado um estudo complementar de espectroscopia de RMN de 1H e de 13C para os compostos K2[MoO2(C2H2O3)2]H2O, K2[MoO2(C8H6O3)2] e K2[MoO3(C4H4O6)]H2O. Os compostos da série M2[MoO2(C2H2O3)2]nH2O são fotossensíveis à radiação UV, sendo o complexo K2[MoO2(C2H2O3)2]H2O, o que apresenta maior fotossensibilidade. O composto Na2[MoO2(C4H4O5)2]uH2O foi obtido a partir de MoO3 e ácido málico utilizando-se a metodologia descrita para os compostos da série M2[MoO2(C2H2O3)2]nH2O. O complexo obtido foi caracterizado por análise elementar, espectroscopia IV e difração de raios X. Com AgNO3 foram obtidos os complexos glicolato, malato, tartarato e mandelato de prata... The aim of this work is study of solid complexes prepared by the reaction of a-hydroxycarboxilic acids or the respectives salts with molybdenum or lead oxides and silver nitrate. Glycolic (C2H4O3), malic (C4H6O5), tartaric (C4H6O6) and mandelic (C8H8O3) acids were the a-hydroxycarboxilic acids used in this work. Thirteen complexes were obtained: six complexes with Mo(VI), four complexes with Ag(I) and three complexes with Pb(II). The complexes (NH4)2[MoO2(C2H2O3)2]H2O, (NH4)2[MoO2(C8H6O3)2] and (NH4)2[MoO3(C4H4O6)] H2O were prepared again in order to measure specific area of the respective oxides after calcination. These three compounds led to the formation of MoO3 with superficial area ranging from 1.0 to 3.0 m2/g. The compounds of the series M2[MoO2(C2H2O3)2]nH2O, where M = Li+, Na+, K+, Rb+ and Cs+, C2H2O3 2- = glicolate2- and n = 1 or u, were synthesized in aqueous medium by the reaction of the respective salt of the glycolic acid with molybdenum trioxide. Molar ratio of 1:2 metal:ligand was used. The solution was concentrated until the formation of a viscous product. The solid complexes were obtained by addition of ethanol. The complexes were characterized by elemental analysis (C, H and O), thermal analysis (TG/DTA), infrared spectroscopy and X-ray diffractometry (powder method). An additional study using nuclear magnetic resonance spectroscopy (1H and 13C) was performed with K2[MoO2(C2H2O3)2]H2O, K2[MoO2(C8H6O3)2] and K2[MoO3(C4H4O6)]H2O. These compounds showed to be photosensitive to the UV radiation. The complex K2[MoO2(C2H2O3)2]H2O was the most photosensitive. The complex Na2[MoO2(C4H4O5)2]uH2O was obtained from MoO3 with malic acid by the use of the same methodology of synthesis of the complexes of type M2[MoO2(C2H2O3)2]nH2O. This complex was characterized by elemental analysis, infrared spectroscopy and X-ray diffractometry... (Complete abstract, click electronic address below)

Published
2004

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