scholarly journals Preparation and Thermogravimetric and Antimicrobial Investigation of Cd (II) and Sn (II) Adducts of Mercaptopyridine, Amino Triazole Derivatives, and Mercaptothiazoline Organic Ligand Moieties

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ahmed Gaber ◽  
Walaa F. Alsanie ◽  
Robson F. de Farias ◽  
Moamen S. Refat

The solid adducts of SnCl2.(3amt).H2O, SnCl2.2(3amt).H2O, CdCl2.(3amt), CdCl2.2(3amt), SnCl2.(2mct).0.5H2O, SnCl2.2(2mct), CdCl2.(2mct), CdCl2.2(2mct).H2O, SnCl2.(2mcp).1.5H2O, >2.2(2mcp).4H2O, CdCl2.(2mcp), CdCl2.2(2mcp), SnCl2.(4amt).4H2O, SnCl2.2(4amt).1.5H2O, CdCl2.(4amt).H2O, and CdCl2.2(4amt) (where the 3amt, 4amt, 2mct, and 2mcp represent 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 2-mercaptothiazoline, and 2-mercaptopyridine simple organic chelates, respectively) were prepared using a solid-state route and investigated by CHN elemental analysis and infrared spectroscopy. Additionally, we investigated the thermogravimetric characterization and antimicrobial proprieties. It is verified that for 3amt and 4amt adducts, the coordination occurs through nitrogen atom. For 2mct compounds, the coordination occurs through nitrogen (Sn) or sulfur (Cd). For 2mcp adducts, both coordination sites nitrogen and sulfur are involved. By examination of TG curves, it is confirmed that for each hydrated compounds, the first mass loss step is linked with the release of water molecules followed by the release of ligand molecules and sublimation of the metal chloride. Furthermore, it is verified that, considering only the release of ligand molecules (3amp, 4amp, 2mct, or 2mcp), the cadmium adducts are always more stable than the correspondent tin adducts probably due to the formation of cross-linking bonds in these compounds. Finally, of these 16 adducts, 14 showed antimicrobial activities against different bacterial and fungal strains.

2006 ◽  
Vol 71 (12) ◽  
pp. 1289-1300 ◽  
Author(s):  
Moamen Refat ◽  
Farias de

The adducts CuCl2?(3amt), CuCl2?2(3amt)?2H2O, CuCl2?3(3amt), CuCl2?(4amt), CuCl2?2(4amt), CuCl2?3(4amt)?2H2O, CuCl2?(2mct)?H2O, CuCl2?2(2mct)?2.5H2O, CuCl2?3(2mct)?2H2O, CuCl2?(2mcp) and CuCl2?2(2mcp)?H2O, where 3-amino-1,2,4-triazole = 3amt, 4-amino-1,2,4-triazole = 4amt, 2-mercaptothiazoline = 2mct and 2-mercaptopyridine = 2mcp, were synthesized by a solid state route and characterized by CHN elemental analysis and infrared spectroscopy. A thermogravimetric study was also performed. It was verified that 4amp is a molecule with a higher ability to act as a bridging ligand in comparison with 3amp. It was also found that, for all compounds, the mono adducts were the most thermally stable ones. Such a fact is in agreement with a higher ionic and covalent character of the metal-ligand bond in surch compounds. .


1988 ◽  
Vol 66 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Camille Chapados ◽  
Denis Girard ◽  
Michel Ringuet

Complexation of water by chlorophyll molecules in natural photosynthetic processes is a matter of great interest. In the present work the influence of water on a model porphyrin, magnesium 2,7,12,17-tetrahexyl-3,8,13,18-tetramethyl porphin (MgTHTMP) has been studied by infrared spectroscopy. A CCl4 (spectroscopic grade) solution of MgTHTMP showed two small bands in the 3600 cm−1 infrared region. These bands are assigned to ν3 and ν1 vibrations of water coordinated to the Mg atom. For MgTHTMP in the solid state, either deposited on an infrared plate or suspended in a Nujol film, none of the OH bands is observed. An elemental analysis confirmed that the solid porphyrin was anhydrous. This evidence indicates that while no water is complexed with MgTHTMP in the solid state, this porphyrin is highly hygroscopic in a CCl4 solution and will easily complex with the few water molecules (less than 0.01%) present in the spectro grade solvent by forming a coordinate bond between the central magnesium atom and the oxygen of water. Several other metallic porphyrins in CCl4 solutions have been studied for comparison with the Mg porphyrin. The spectra of these substances did not show any complexed water. A model of the H2O–MgTHTMP interaction is given and the implication of this model on the aggregation states of chlorophyll will be discussed.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Toshinari Ezawa ◽  
Yutaka Inoue ◽  
Isamu Murata ◽  
Koichi Takao ◽  
Yoshiaki Sugita ◽  
...  

The purpose of this study was to evaluate the physicochemical properties of piperine (PP) in ground mixtures (GMs) of PP with α-, β-, or γ-cyclodextrin (CD) under conditions of humidity, heat, and humidity-heat. In solid-state fluorescence measurements, the fluorescence maxima for GM (PP/αCD = 1/2), GM (PP/βCD = 1/1), and GM (PP/γCD = 1/1) were observed at 463, 472, and 469 nm, respectively. On the other hand, the humidified GMs exhibited maxima at 454, 460, and 465 nm, while the humidified-heated samples displayed fluorescence maxima at 455, 455, and 469 nm, respectively. Therefore, the molecular behavior of PP with α, β, and γCD was concluded to vary upon the coordination of water molecules. NIR and solid-state fluorescence measurements revealed that the molecular behavior of PP inside the α, β, and γCD cavity changed by water and heat factors depends on the mobility of the methylenedioxyphenyl group.


1997 ◽  
Vol 52 (11) ◽  
pp. 1325-1330 ◽  
Author(s):  
M. C. Apella ◽  
A. Terron ◽  
J. J. Fiol ◽  
V. Moreno ◽  
E. Molins

The interaction between Ni(II) and amino acids with an aromatic residue (such as tyrosine and tryptophan) and either 9 substituted bases or nucleosides has been studied. Ternary derivatives obtained in solid state were characterised by, among other techniques, elemental analysis, thermogravimetry, electronic and infrared spectroscopy. The following complexes have been obtained: 1: [Ni (tyr)2(9EtAde)2] × 4H2O; 2: [Ni (tyr)2(9EtGua)2] × 5H2O; 3: [Ni (tyr)(guo) × 5H2O];4: [Ni (tyr)(ino) × 5H2O];5: [Ni (trp)2(9EtGua)(H2O)] × 2H2O, where tyr is tyrosinate, trp tryptophanate, ino inosinate and guo guanosinate. Thermogrammes are in agreement with the number of water molecules and nickel content (calculated as NiO), together with the ternary nature of these complexes. The binary compounds Ni(tyr)2 × 3H2O and Ni(trp)2 × 3.5H2O were also obtained and the corresponding thermogrammes were registered for comparison purposes. Compounds 1, 2 and5 are water soluble; besides, 1 is fairly soluble in methanol. Compounds 3 and 4 seem to be polymeric. Infrared spectra clearly show the presence of bands either from the amino acid or the base suggesting nickel octahedral coordination through the carboxylic and amino acids groups and a nitrogen from the purine base. These compounds were obtained in water at pH close to 7.0. With other bases such as cytosine and uracil, or their corresponding nucleosides, the same synthesis failed to yield ternary compounds [1,2].


2020 ◽  
Vol 15 ◽  
Author(s):  
Ashish Katoch ◽  
Manju Nagpal ◽  
Malkiet Kaur ◽  
Manjinder Singh ◽  
Geeta Aggarwal ◽  
...  

Background: Controlled oral dosage forms have always been preferred for drugs with variable absorption, and short biological half life and frequent dosing. The prime goal with sustained release systems is to maintain uniform therapeutic blood levels for longer periods of time. Interpenetrating networks (IPNs) have been evidenced as uniform sustained release systems. In current study, polyvinyl alcohol (PVA) and locust bean gum (LBG) based IPNs were developed for the oral sustained release drug delivery of gliclazide (shows variable absorption). Method: The IPNs were synthesized by emulsion cross-linking method using glutaraldehyde (GA) as a cross linking agent. Gliclazide is a potential second generation, short-acting sulfonylurea oral hypoglycemic agent is having a short biological half-life (2-4 h), variable absorption and poor oral bioavailability. Various batches of IPNs were formulated by varying LBG: PVA ratio and evaluated for percentage yield, drug entrapment efficiency (DEE), swelling properties and in vitro drug release studies. Further characterizations were done by Fourier Transform Infrared Spectroscopy (FTIR), C13 Solid state NMR, X-Ray diffraction study (XRD), Scanning electron microscopy (SEM), and Differential scanning microscopy (DSC) studies. Results: The percentage yield, drug entrapment and equilibrium swelling was observed to be dependent on PVA-LBG ratio and GA amount. Sustained release of drug was observed in all IPN formulations (approx 59 - 86% in 8 h in various batches) with variable release kinetics. SEM studies revealed the regular structures of IPNs. FTIR, XRD, C13 Solid state NMR and DSC studies proposed that drug was successfully incorporated into the formed IPNs. Conclusion: IPNs of LBG and PVA can be used as a promising carrier with uniform sustained release characteristics.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1320
Author(s):  
Shaik Gouse Peera ◽  
Ravindranadh Koutavarapu ◽  
Chao Liu ◽  
Gaddam Rajeshkhanna ◽  
Arunchander Asokan ◽  
...  

Electrochemical water splitting is considered a promising way of producing hydrogen and oxygen for various electrochemical energy devices. An efficient single, bi-functional electrocatalyst that can perform hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) is highly essential. In this work, Co@NC core-shell nanoparticles were synthesized via a simple, eco-friendly, solid-state synthesis process, using cobalt nitrate and with pyrazole as the N and C source. The morphological analysis of the resulting Co@NC nanoparticles was performed with a scanning and transmission electron microscope, which showed Co nanoparticles as the core and the pyrolysis of pyrazole organic ligand N-doped carbon derived shell structure. The unique Co@NC nanostructures had excellent redox sites for electrocatalysis, wherein the N-doped carbon shell exhibited superior electronic conductivity in the Co@NC catalyst. The resulting Co@NC nanocatalyst showed considerable HER and OER activity in an alkaline medium. The Co@NC catalyst exhibited HERs overpotentials of 243 and 170 mV at 10 mA∙cm−2 on glassy carbon and Ni foam electrodes, respectively, whereas OERs were exhibited overpotentials of 450 and 452 mV at a current density of 10 and 50 mA∙cm−2 on glassy carbon electrode and Ni foam, respectively. Moreover, the Co@NC catalyst also showed admirable durability for OERs in an alkaline medium.


RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3346-3353
Author(s):  
Iman Khaldari ◽  
Mohammad Reza Naghavi ◽  
Elaheh Motamedi

Among the conventional methods in synthesizing nanoparticles, the methods that use biological resources, as reducing and stabilizing agents, can be considered eco-friendly methods.


2007 ◽  
Vol 336-338 ◽  
pp. 377-380 ◽  
Author(s):  
Jian Hong Shen ◽  
Ji Zhou ◽  
Xue Min Cui ◽  
Yue Hui Wang

A series of ferrroelectric-ferromagnetic composites were synthesized from BaTiO3 and NiFe2O4 ferrite by conventional solid-state route. XRD studies indicated that the composites comprised of only two phases, BaTiO3 phase with perovskite structure and NiFe2O4 phase with spinel structure. Frequency dependence of permittivity and permeability were also measured. Experimental results showed that the dielectric constant and initial permeability of these composites could be tunable by varying the composition of composites. Thus, these composites can be used for multilayer chips EMI filters.


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