scholarly journals Structural differences between humic fractions from different soil types as determined by FT-IR and 13 C-NMR studies

1989 ◽  
Vol 81-82 ◽  
pp. 187-194 ◽  
Author(s):  
R. Fründ ◽  
H.-D. Lüdemann ◽  
F.J. Gonzalez-Vila ◽  
G. Almendros ◽  
J.C. del Rio ◽  
...  
1999 ◽  
Vol 23 (3) ◽  
pp. 202-203
Author(s):  
Daniel A. Fletcher ◽  
Brian G. Gowenlock ◽  
Keith G. Orrell ◽  
David C. Apperley ◽  
Michael B. Hursthouse ◽  
...  

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Harshita Sachdeva ◽  
Diksha Dwivedi ◽  
Rekha Saroj

Alum (KAl(SO4)2·12H2O) is an inexpensive, efficient, and nontoxic catalyst used for the synthesis of 2-[3-amino-5-methyl-5-(pyridin-3-yl)-1,5-dihydro-4H-1,2,4-triazol-4-yl]propanoic acid derivatives in aqueous media by the reaction of 3-acetyl pyridine(1), amino acids(2)/(6), and thiosemicarbazide(4)at 80°C. This methodology offers significant improvements for the synthesis of products with regards to the yield of products, simplicity in operation, and green aspects by avoiding toxic catalysts which uphold the motto of green chemistry. Synthesized compounds have been characterized by FT-IR,13C NMR, and1HNMR spectroscopy.


Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


2000 ◽  
Vol 78 (3) ◽  
pp. 316-321
Author(s):  
G W Buchanan ◽  
A B Driega ◽  
G PA Yap

The title complex is asymmetric in the crystal due to the spatial orientation of the NCS function. The space group has been determined to be P21 with a = 9.496(3), b = 8.736(3), c = 9.676(3) Å, β = 117.859(5)°, and Z = 2. The solid state 13C NMR spectrum is consistent with the lack of symmetry in the crystal and there is little evidence for large amplitude motion in the macrocycle as determined from the dipolar dephased spectrum.Key words: macrocyclic crown ether, lithium complex.


Author(s):  
Marta K. Jamróz ◽  
Michał H. Jamróz ◽  
Jan Cz. Dobrowolski ◽  
Jan A. Gliński ◽  
Michał Gleńsk

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hooshang Hamidian

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, andN,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a–5f) showed the most potent mushroom tyrosinase inhibition (IC50values in the range of 4.39 ± 0.76–1.71 ± 0.49 µM), comparable to the kojic acid, as reference standard inhibitor. All the novel compounds were characterized by FT-IR,1H NMR,13C NMR, and elemental analysis.


2020 ◽  
Vol 5 (1) ◽  
pp. 54
Author(s):  
Erwin Indriyanti ◽  
Masitoh Suryaning Prahasiwi

<p>Cinnamic acid plays a vital role in the synthesis of other important compounds and as a precursor for the synthesis of commercial cinnamon esters used in perfumery, cosmetics, and pharmaceutical industries. The aim of this research is to synthesize cinnamic acid using sonochemical methods. Cinnamic acid was synthesized using Perkin reaction by reacting 0.05 mole of benzaldehyde with 0.073 mole of acetic acid anhydride and 0.03 mole of sodium acetate as a catalyst in the Erlenmeyer flask and then the mixture was put in a sonicator for 60 minutes at 70 <sup>o</sup>C. The synthesized compound was tested organoleptic properties, and the melting point was measured. The chemical structure was elucidated using FT-IR, H-NMR, and <sup>13</sup>C-NMR. The photoprotective activity was examined from its antioxidant and SPF values. The synthesized compound was found in the form of a shiny white fine crystal which had distinctive odor with a yield of 4.98% and the melting point was found at 133<sup> o</sup>C. In the structure elucidation using FT-IR (the aromatic ring absorption at the wave number 1580 cm<sup>-1</sup> -1600 cm<sup>-1</sup>. The wave number 1625 cm<sup>-1</sup>is an aromatic conjugated alkene group, while wave  number 1689.4 cm<sup>-1 </sup>is a carbonyl group. The wave number 2500 cm<sup>-1 </sup>– 3250 cm<sup>-1 </sup>is an OH carboxylic acid group) , H-NMR (7.410 (<em>m</em>, 5H, Ar-H); 7.425(<em>t</em>, 1H); 7.572 (<em>d</em>, 1H); 8.057 (d, 1H,C=CH) and <sup>13</sup>C-NMR (129.309 ppm; 130.998 ppm; 134.58 ppm; 170.017 ppm) showed that when compared with the standard compound as the reference, the synthesized compound was confirmed to be cinnamic acid. The antioxidant activity test showed that at the concentration of 20 ppm the synthesized compound was able to reduce free radicals by 46.69%. This finding showed that  the synthesized compound had antioxidant activity.</p>


1987 ◽  
Vol 109 (12) ◽  
pp. 3596-3602 ◽  
Author(s):  
L. Steven Hollis ◽  
Eric W. Stern ◽  
Alan R. Amundsen ◽  
Arthur V. Miller ◽  
Sheryl L. Doran

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