The oscillatory Belousov–Zhabotinsky reaction with flavones in batch systems using aqueous–DMF mixed medium

1994 ◽  
Vol 72 (6) ◽  
pp. 1537-1540 ◽  
Author(s):  
G. Maya ◽  
P.V. Lalitha ◽  
R. Ramaswamy

Oscillatory systems of the Belousov–Zhabotinsky type with flavones as substrates are described for the first time. Since quercetin and morin are water insoluble, a mixed medium containing DMF and water was used with one of the three catalysts Ce(III), ferroin, or Mn(II). The oscillatory behaviour of a water-soluble substrate (gallic acid) was studied in nine different aqueous–organic mixed media as well as in pure aqueous medium in the bromate–Ce(III) system. The results obtained from a catalyzed system with quercetin or morin as the substrate in an aqueous–organic mixed medium are in agreement with the accepted (FKN) mechanism for an aqueous system.

1992 ◽  
Vol 57 (11) ◽  
pp. 2235-2240 ◽  
Author(s):  
Punchayil Velayudhan Nair Lalitha ◽  
Renganathan Ramaswamy

The Briggs-Rauscher reaction with substrates containing acidic hydrogen such as malonic acid, acetonyl acetone has been studied. The employment of mixed media involving an organic solvent and water enabled the study of water-insoluble substrates. The present communication reports the oscillatory behaviour of malonic acid in the iodate system in different mixed media (5 vol.% of the organic solvent) as well as the oscillatory behaviour of seven substrates in acetonitrile-water mixed medium of which two are new substrates hitherto unreported in any of the oscillatory systems.


Author(s):  
Ole V. Petersen ◽  
Alexander P. Khomyakov ◽  
Henning Sørensen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Petersen, O. V., Khomyakov, A. P., & Henning. (2001). Natrophosphate from the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 139-141. https://doi.org/10.34194/ggub.v190.5184 _______________ The rare mineral natrophosphate has been identified for the first time in the Ilímaussaq alkaline complex in a drill core from the Kvanefjeld area. It occurs sparsely in zoned veinlets with cores of natrophosphate and borders of fibrous trona. The natrophosphate is more or less smoky, transparent and unaltered. The refractive index n = 1.448 ± 0.005 is low compared to that given for the material from the type locality, Khibina alkaline complex, Kola Peninsula; the unit cell parameter a = 27.76 ± 0.05 Å is in excellent agreement with that given for the material from the type locality. The veins occur in hyper-agpaitic naujakasite lujavrite; villiaumite is an associated mineral. Only a few water-soluble minerals have so far been found in the Ilímaussaq alkaline complex compared to the wealth of such minerals in the Khibina and Lovozero alkaline complexes. This is possibly at least partly due to lack of necessary precautions during sampling.


2016 ◽  
Vol 7 (45) ◽  
pp. 6895-6900 ◽  
Author(s):  
Biswajit Saha ◽  
Kamal Bauri ◽  
Arijit Bag ◽  
Pradip K. Ghorai ◽  
Priyadarsi De

Herein, we have designed and synthesized a novel traditional fluorophore-free water-soluble fluorescent copolymer based on a poly(maleimide-alt-styrene) skeleton, which responds to both pH and temperature in aqueous medium.


2016 ◽  
Vol 40 (5) ◽  
pp. 4756-4760 ◽  
Author(s):  
Bin Hua ◽  
Li Shao ◽  
Jiong Zhou ◽  
Guocan Yu

A water-soluble hybrid[4]arene was synthesized for the first time and its pH-responsive host–guest complexation with paraquat in water was investigated. This new host–guest recognition motif was further applied in the construction of a supra-amphiphile.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.


The Analyst ◽  
2018 ◽  
Vol 143 (1) ◽  
pp. 250-257 ◽  
Author(s):  
Soham Samanta ◽  
Senjuti Halder ◽  
Poulomi Dey ◽  
Utsab Manna ◽  
Aiyagari Ramesh ◽  
...  

A new water soluble and fluorogenic probe (L) that can demonstrate the specific ratiometric detection of a SO2derivative (SO32−) in 100% aqueous medium and live cells has been designed and synthesized.


2019 ◽  
Vol 43 (34) ◽  
pp. 13371-13380 ◽  
Author(s):  
Sheikdawood Parveen ◽  
Thathan Premkumar ◽  
Hung Huy Nguyen ◽  
Subbiah Govindarajan

For the first time, a new hydrazone Schiff base ligand and its Co(ii), Ni(ii), and Cu(ii) complexes were synthesised and characterised. Their antioxidant and binding activities towards CT-DNA and BSA were evaluated.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2702
Author(s):  
Ivy L. Librando ◽  
Abdallah G. Mahmoud ◽  
Sónia A. C. Carabineiro ◽  
M. Fátima C. Guedes da Silva ◽  
Carlos F. G. C. Geraldes ◽  
...  

The N-alkylation of 1,3,5-triaza-7-phosphaadamantane (PTA) with ortho-, meta- and para-substituted nitrobenzyl bromide under mild conditions afforded three hydrophilic PTA ammonium salts, which were used to obtain a new set of seven water-soluble copper(I) complexes. The new compounds were fully characterized and their catalytic activity was investigated for the low power microwave assisted one-pot azide–alkyne cycloaddition reaction in homogeneous aqueous medium to obtain disubstituted 1,2,3-triazoles. The most active catalysts were immobilized on activated carbon (AC), multi-walled carbon nanotubes (CNT), as well as surface functionalized AC and CNT, with the most efficient support being the CNT treated with nitric acid and NaOH. In the presence of the immobilized catalyst, several 1,4-disubstituted-1,2,3-triazoles were obtained from the reaction of terminal alkynes, organic halides and sodium azide in moderate yields up to 80%. Furthermore, the catalyzed reaction of terminal alkynes, formaldehyde and sodium azide afforded 2-hydroxymethyl-2H-1,2,3-triazoles in high yields up to 99%. The immobilized catalyst can be recovered and recycled through simple workup steps and reused up to five consecutive cycles without a marked loss in activity. The described catalytic systems proceed with a broad substrate scope, under microwave irradiation in aqueous medium and according to “click rules”.


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