Direct preparation of polysilicic acid flocculant by using pickling waste liquor of metal plate

2020 ◽  
Vol 36 ◽  
pp. 101267 ◽  
Author(s):  
Xuesong Huang ◽  
Yingjie Zhang ◽  
Xue Li ◽  
Jianguo Duan ◽  
Bin Xu ◽  
...  
2013 ◽  
Vol 51 (7) ◽  
pp. 535-545 ◽  
Author(s):  
Kwang-Seok Lee ◽  
Su-Eun Lee ◽  
Jung Su Kim ◽  
Min Jung Kim ◽  
Dong Hyun Bae ◽  
...  

2020 ◽  
Author(s):  
Aidan Kelly ◽  
Peng-Jui (Ruby) Chen ◽  
Jenna Klubnick ◽  
Daniel J. Blair ◽  
Martin D. Burke

<div> <div> <div> <p>Existing methods for making MIDA boronates require harsh conditions and complex procedures to achieve dehydration. Here we disclose that a pre-dried form of MIDA, MIDA anhydride, acts as both a source of the MIDA ligand and an in situ desiccant to enable a mild and simple MIDA boronate synthesis procedure. This method expands the range of sensitive boronic acids that can be converted into their MIDA boronate counterparts. Further utilizing unique properties of MIDA boronates, we have developed a MIDA Boronate Maker Kit which enables the direct preparation and purification of MIDA boronates from boronic acids using only heating and centrifuge equipment that is widely available in labs that do not specialize in organic synthesis. </p> </div> </div> </div>


2020 ◽  
Vol 7 (2) ◽  
pp. 226-238
Author(s):  
Petro P. Ony`sko ◽  
Tetyana I. Chudakova ◽  
Vladimir V. Pirozhenko ◽  
Alexandr B. Rozhenko

The potentialities of condensation of α-ketophosphonates with primary amines for direct synthesis of α-iminophosphonates have been revealed. Diesters of α-ketophosphonic acids react with the primary amines by two competitive pathways: with a formation of α-iminophosphonates or a C-P bond cleavage resulting in a hydrogen phosphonate and an acylated amine. In many cases, the latter undesirable pathway is dominant, especially for more nucleophilic alkyl amines. Using metallic salts of α-ketophosphonates avoids the C-P bond cleavage, allowing direct preparation of α-phosphorylated imines by the reaction with primary amines. This strategy provides an atom economy single-stage synthesis of iminophosphonates – precursors of bio relevant phosphorus analogs of α-amino acids. Methyl sodium iminophosphonates, bearing aryl or heteryl substituents at the imino carbon atom exist in solutions at room temperature as an equilibrium mixture of Z- and E-isomers. A configuration of the C=N bond can be controlled by the solvent: changing the aprotic dipolar solvent DMSO-d6 by water or alcohols leads to the change from a predominant Z-isomer to almost an exclusive E-form. In contrast, diesters of the respective iminophosphonates exist in non-protic solvents predominantly in Econfiguration. The solvent effect on E-Z stereochemistry is demonstrated by DFT calculations.


Sugar Tech ◽  
2021 ◽  
Author(s):  
Arkadiusz Artyszak ◽  
Małgorzata Kondracka ◽  
Dariusz Gozdowski ◽  
Alicja Siuda ◽  
Magda Litwińczuk-Bis

AbstractThe effect of marine calcite, a mixture of ortho- and polysilicic acid as well as orthosilicic acid applied as a foliar spray on the chemical composition of sugar beet leaves in the critical phase of nutrient supply (beginning of July) but also leaves and roots during harvest time in 2015–2016, was studied. The content of silicon in the leaves ranged from 1.24 to 2.36 g kg−1 d.m. at the beginning of July, 3.85–5.34 g kg−1 d.m. during harvest and 2.91–4.20 g kg−1 d.m. in the roots. The foliar application of silicon caused a significant increase in the content of magnesium and calcium in leaves (in July) as compared to the control. The sugar beet consumes approx. 75 kg Si ha−1, which is almost 3.5 times more than P and 20% more than Mg thus proving its importance for its species. About 70% of the silicon taken up by sugar beet is stored in roots and 30% in leaves. The pure sugar yield is most favorably influenced by two- and threefold foliar application of the product containing silicon in the form of orthosilicic acid stabilized with choline, and a threefold mixture of ortho- and polysilicic acid. The increase in the pure sugar yield is not the result of a change in the chemical composition of sugar beet plants, but their more efficient functioning after foliar application of silicon under stress conditions caused by water shortage.


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