31p Nmr
Mostrando 1-12 de 352 artigos, teses e dissertações.
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1. Synthesis, Spectroscopic Characterization, DFT Calculations and Preliminary Antifungal Activity of New Piperine Derivatives
Four new piperine derivatives, PC1-PC4, were synthesized, and their structures were fully characterized by infrared (IR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopies. Quantum chemical calculations were performed using density functional theory (DFT) with the B3LYP-D3/6-31G(d,p) and 6-311+G(2d,p) basis sets. Electronic properties, such as th
J. Braz. Chem. Soc.. Publicado em: 2021-03
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2. An Efficient and Recyclable Sn-Based Phosphotungstic Acid with Tunable Brønsted/Lewis Acidity for Selective Oxidation of Benzyl Alcohol
A series of metal ion (M = Sn2+, Fe3+, Ni2+, Co2+, Ag+, Cu2+) exchanged tungstophosphoric acid (H3PW12O40; TPA) catalysts with tunable Brønsted/Lewis acidity were synthesized and exploited for the oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using hydrogen peroxide (H2O2) as oxidant. The structure of these M-TPA composite salts was also characte
J. Braz. Chem. Soc.. Publicado em: 2021-01
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3. Should kidney transplants during the COVID-19 pandemic be canceled or maintained?
The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (d
Rev. Assoc. Med. Bras.. Publicado em: 2020-07
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4. New Heteroleptic RuII/Diphosphine Complexes with Cytotoxicity against Human Breast and Murine Ascitic Sarcoma 180 Tumor Cells
The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (d
J. Braz. Chem. Soc.. Publicado em: 2020-07
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5. Crystal Structure and 1H NMR Experimental and Theoretical Study of Conformers of 5-Methyl-1-(4’-methylphenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester and 5-Methyl-1-(phenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester
We reported experimental and theoretical investigation of conformers of 1,2,3-triazole derivatives, substances of exclusively synthetic origin, subject of extensive studies, because of several biological properties, such as antiviral, antimicrobial and antileishmaniasis. We reported molecular/supramolecular X-ray structures of antiophidian compounds I and II
J. Braz. Chem. Soc.. Publicado em: 2020-05
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6. Acid-Catalyzed Z-E Isomerization of γ-Alkylidenebutenolides: An Experimental and DFT Study
The Z-E isomerization of γ-alkylidenebutenolide analogues to natural nostoclides and other natural butenolides was investigated using 1H nuclear magnetic resonance (NMR) and high performance liquid chromatography (HPLC) data as well as density functional theory (DFT) calculations at the wB97x-D/6-31G(d,p) level, including solvent effects with the polarizabl
J. Braz. Chem. Soc.. Publicado em: 2020-01
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7. Structure/Activity of PtII/N,N-Disubstituted-N'-acylthiourea Complexes: Anti-Tumor and Anti-Mycobacterium tuberculosis Activities
The syntheses, characterization, cytotoxicity against tumor cells and anti-Mycobacterium tuberculosis activity assays of PtII/PPh3/N,N-disubstituted-N'-acylthioureas complexes with general formulae [Pt(PPh3)2(L)]PF6, PPh3 = triphenylphosphine; L = N,N-disubstituted-N'-acylthiourea, are here reported. The complexes were characterized by elemental analysis, mo
J. Braz. Chem. Soc.. Publicado em: 2018-06
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8. Synthesis of New Conjugates 1H-Pyrazolo[3,4-b]pyridine-phosphoramidate and Evaluation against Leishmania amazonensis
In this research three series of substituted 1H-pyrazolo[3,4-b]pyridine phosphoramidates were synthesized and characterized by infrared, 1H, 13C, and 31P nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. The products were obtained in good yields (67-83%) under mild conditions by nucleophilic aromatic substitution reaction o
J. Braz. Chem. Soc.. Publicado em: 2018-01
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9. Conformational Analysis, Experimental and GIAO-DFT 13C NMR Chemical Shift Calculation on 2’-Hydroxy-3,4,5-trimethoxy-chalcone
In this paper we investigated the ability of the GIAO-mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level of theory to predict the 13C nuclear magnetic resonance (NMR) chemical shifts of the 2’-hydroxy-3,4,5-trimethoxy-chalcone molecule. Two different approaches were used. First: the absolute shieldings σ for all carbon atoms in each geometrically optimized confor
J. Braz. Chem. Soc.. Publicado em: 2017-11
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10. Polypyridyl Ruthenium Complexes: Novel DNA-Intercalating Agents against Human Breast Tumor
This paper describes a new series of four DNA-intercalating agents with promising anticancer activities, based on ruthenium(II) with the planar ligand dpqQX (dpqQX = dipyrido[3,2-a:2',3'-c]quinoxaline[2,3-b]quinoxaline). The complexes identified as trans-[RuCl2(dppb)(dpqQX)], cis-[RuCl2(dppb)(dpqQX)], ct-[RuCl(CO)(dppb)(dpqQX)]PF6 and ct-[RuCl2(PPh3)2(dpqQX)
J. Braz. Chem. Soc.. Publicado em: 2017-10
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11. Decomposition Dynamics of Typha angustifolia under Aerobic Conditions
The study of the Typha species has gained attention in tropical areas due to their rapid growth, nutrient release, and contribution to detritus in lakes. Analysis of the degradation of Typha angustifolia has shown that the first stage of decomposition is marked primarily by the release of soluble compounds, indicating that microorganisms have a minor influen
J. Braz. Chem. Soc.. Publicado em: 2016-09
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12. SYNTHESIS OF PROPYLENE FROM ETHANOL USING PHOSPHORUS-MODIFIED HZSM-5
Abstract Effects of phosphorus addition to HZSM-5 on ethanol conversion to propylene were evaluated. Catalysts were characterized by XRF, XRD, nitrogen adsorption, 27Al and 31P MAS NMR, n-propylamine and ammonia TPD. Increasing P content decreased the strength and density of acid total sites. Ethanol dehydration was carried out in a fixed bed reactor operati
Braz. J. Chem. Eng.. Publicado em: 2016-09