Synthesis of a New Hyperbranched Pyridylphenylene Polymer Based on an АB2 Monomer and a Pair of АB/АB2 Monomers

INEOS OPEN ◽  
2020 ◽  
Author(s):  
A. S. Torozova ◽  
◽  
E. S. Serkova ◽  
I. Yu. Krasnova ◽  
A. A. Korolkova ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Functional Groups ◽  
Intramolecular Cyclization ◽  
Reaction System ◽  
Average Molecular Mass ◽  
Triple Bonds ◽  
Limited Degree ◽  
First Time

A hyperbranched pyridylphenylene polymer with the weight average molecular mass of 56000 Da is synthesized for the first time from an AB2 monomer bearing one diene and two internal triple bonds. The introduction of a linear AB comonomer into the reaction system leads to an increase in the yield of the polymer which has the weight average molecular mass of 21400 Da. Due to the limited degree of intramolecular cyclization, the high content of functional groups facilitates the formation of defect-free structures and provides an opportunity to modify the resulting polymers.

Extraction of polyethylene glycols with dicarbolide solutions in nitrobenzene

1990 ◽  
Vol 55 (8) ◽  
pp. 1959-1967 ◽  
Author(s):  
Petr Vaňura ◽  
Pavel Selucký
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Mass ◽  
Extraction Constant ◽  
Metal Extraction ◽  
Polyethylene Glycols ◽  
Relative Molecular Mass ◽  
Published Data ◽  
Average Molecular Mass ◽  
Peg 400 ◽  
Extraction Constants

The extraction of polyethylene glycol of average molecular mass 400 (PEG 400) with dicarbolide solution in nitrobenzene and of longer-chain polyethylene glycol, of average molecular mass 1 500 (PEG 1 500), with chlorinated dicarbolide solution in nitrobenzene was studied. During the extraction of PEG 400, the polyethylene glycol solvates the Horg+ ion in the organic phase giving rise to the HLorg+ species (L is polyethylene glycol). The obtained value of the extraction constant Kex(HLorg+) = 933 is consistent with published data of metal extraction. Extraction of PEG 1 500 was treated applying the simplified assumption that the thermodynamic behaviour of PEG 1 500 is the same as that of n molecules of polyethylene glycol with relative molecular mass 1 500/n, each solvating one cation. For this model, the value of n = 3.2 ± 1.1 and the values of the extraction constants of the HL1/n,org+ and HL2/n,org+ species were obtained by using the adapted program LETAGROP. This value of n is consistent with published extraction data in the presence of polyethylene glycol with a relative molecular mass from 200 to 1 000.

scholarly journals Nanomechanical Molecular Mass Sensing Using Suspended Microchannel Resonators

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3337
Author(s):  
Alberto Martín-Pérez ◽  
Daniel Ramos ◽  
Javier Tamayo ◽  
Montserrat Calleja
Keyword(s):  
Molecular Mass ◽  
Mass Density ◽  
Applied Pressure ◽  
Atomic Mass ◽  
Liquid Sample ◽  
Mass Sensing ◽  
Average Molecular Mass ◽  
Fluid Properties ◽  
Molecular Masses ◽  
Microchannel Resonators

In this work we study the different phenomena taking place when a hydrostatic pressure is applied in the inner fluid of a suspended microchannel resonator. Additionally to pressure-induced stiffness terms, we have theoretically predicted and experimentally demonstrated that the pressure also induces mass effects which depend on both the applied pressure and the fluid properties. We have used these phenomena to characterize the frequency response of the device as a function of the fluid compressibility and molecular masses of different fluids ranging from liquids to gases. The proposed device in this work can measure the mass density of an unknown liquid sample with a resolution of 0.7 µg/mL and perform gas mixtures characterization by measuring its average molecular mass with a resolution of 0.01 atomic mass units.

Aureobasidium pullulans Gene from Egypt

2021 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Hani Moubasher ◽  
Salwa S Wahsh ◽  
Nabil Abo El-Kassem ◽  
Refaat Ali
Keyword(s):  
Molecular Mass ◽  
Genomic Dna ◽  
Aureobasidium Pullulans ◽  
Hypothetical Protein ◽  
Significant Alignment ◽  
First Time

Sequancing of pullulanase from the fungus Aureobasidium pullulans isolated from Egypt soil; Genomic DNA of pullulanase was determined for the first time using PCR, according to Baser program, Pullulanase nucleotide collection from Aureobasidium pullulans was blasted which showed similarity using NCBI significant alignment with Aureobasidium namibiae CBS 147.97 hypothetical protein partial mRNA and 46 % with Aureobasidium pullulans JQ624241 and AF470619; Identified sequenced fragment was 2051 bp. and G+C content is 50.5% with molecular mass 63 KDa.

scholarly journals Correlation between Yield and Reduced Mass of Raw Materials in Intermolecular and Intramolecular Cyclization Reactions

2020 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Intramolecular Cyclization ◽  
Raw Materials ◽  
Reaction System ◽  
Diels Alder ◽  
Regression Equation ◽  
Reaction Site ◽  
Coupling Reactions ◽  
Cyclization Reactions ◽  
Intermolecular Reaction ◽  
Intermolecular Reactions

Correlation between yield and reduced mass of raw materials in intramolecular C-N, C-C, C-O coupling reactions and intramolecular/intermolecular Diels-Alder reactions was revealed. The regression equation was found to be the same as that of intermolecular reactions; yield = -0.1861<i>M</i><sub>AB</sub>/(<i>n</i><sub>A</sub><i>n</i><sub>B</sub><i>n</i><sub>I</sub>)+100.0, where <i>M</i><sub>AB</sub> is the reduced mass per mole and <i>n</i><sub>A</sub> and <i>n</i><sub>B</sub> are the total number of each reaction site in molecular A and molecular B in the reaction system, and <i>n</i><sub>I</sub> is the number to distinguish whether it is a intramolecular reaction or intermolecular reaction.

scholarly journals Levan-Producing Leuconostoc citreum Strain BD1707 and Its Growth in Tomato Juice Supplemented with Sucrose

2015 ◽  
Vol 82 (5) ◽  
pp. 1383-1390 ◽  
Author(s):  
Jin Han ◽  
Xiaofen Xu ◽  
Caixia Gao ◽  
Zhenmin Liu ◽  
Zhengjun Wu
Keyword(s):  
Molecular Mass ◽  
Sugar Content ◽  
Carbon Sources ◽  
Viable Cell ◽  
Monosaccharide Composition ◽  
Tomato Juice ◽  
Average Molecular Mass ◽  
Content Type ◽  
Leuconostoc Citreum ◽  
Sucrose Medium

ABSTRACTA levan-producing strain, BD1707, was isolated from Tibetan kefir and identified asLeuconostoc citreum. The effects of carbon sources on the growth ofL. citreumBD1707 and levan production in tomato juice were measured. The changes in pH, viable cell count, sugar content, and levan yield in the cultured tomato juice supplemented with 15% (wt/vol) sucrose were also assayed.L. citreumBD1707 could synthesize more than 28 g/liter of levan in the tomato juice-sucrose medium when cultured at 30°C for 96 h. Based on the monosaccharide composition, molecular mass distribution, Fourier transform infrared (FTIR) spectra, and nuclear magnetic resonance (NMR) spectra, the levan synthesized byL. citreumBD1707 was composed of a linear backbone consisting of consecutive β-(2→6) linkedd-fructofuranosyl units, with an estimated average molecular mass of 4.3 × 106Da.

A phenanthroline-based porous organic polymer for the iridium-catalyzed hydrogenation of carbon dioxide to formate

2019 ◽  
Vol 7 (23) ◽  
pp. 14019-14026 ◽  
Author(s):  
Gunniya Hariyanandam Gunasekar ◽  
Sungho Yoon
Keyword(s):  
Carbon Dioxide ◽  
Functional Groups ◽  
Single Site ◽  
Organic Polymer ◽  
Selective Catalyst ◽  
Porous Organic Polymer ◽  
Highly Active ◽  
First Time ◽  
Hydrogenation Of Carbon Dioxide ◽  
Hydrogenation Of Co

A novel phenanthroline-functionalized porous organic polymer (phen-POP) has been designed, and prepared for the first time without other reactive functional groups in the polymer skeleton. Post-synthetic metalation of phen-POP with IrCl3 afforded a single-site, highly active and selective catalyst for the hydrogenation of CO2 to formate.

Electrochemical Synthesis of 2-Hydroxy-para-terphenyls by Dehydrogenative Anodic C–C Cross-Coupling Reaction

Synlett ◽  
2019 ◽  
Vol 30 (10) ◽  
pp. 1174-1177 ◽  
Author(s):  
Sebastian Lips ◽  
Robert Franke ◽  
Siegfried R. Waldvogel
Keyword(s):  
Functional Groups ◽  
Electrochemical Synthesis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Wide Range ◽  
Broad Variety ◽  
First Time ◽  
Fast Access

The anodic C–C cross-coupling reaction provides fast access to a wide range of bi- and terarylic scaffolds by electrochemically mediated arylation reactions. Herein, a metal- and reagent-free electrosynthetic protocol for the synthesis of nonsymmetrical 2-hydroxy-para-teraryl derivatives is presented for the first time. It is scalable, easy to conduct, and allows the use of a broad variety of different functional groups.

Darstellung von Peroxotantalaten durch Perhydrolyse von Tantal(V)-äthanolat / Preparation of Peroxotantalates by Perhydrolysis of Tantalum(V)ethoxide

1973 ◽  
Vol 28 (9-10) ◽  
pp. 590-594 ◽  
Author(s):  
J. Fuchs ◽  
D. Lubkoll
Keyword(s):  
Petroleum Ether ◽  
Molecular Mass ◽  
Water Soluble ◽  
Organic Cations ◽  
Water Soluble Compound ◽  
Soluble Compound ◽  
First Time

Tetraperoxotantalates with organic cations as well as an oligomeric peroxopolytantalate were prepared for the first time by perhydrolysis of tantalum(V)ethoxide, Ta(OC2H5)5, in the presence of bases. Guanidinium, tert-butylammonium and cyclohexylammonium salts of tetraperoxotantalic acid crystallize from ethanol as relatively stable compounds. The cell constants of these compounds are determined. By perhydrolysis of the ester in petroleum ether the tert-butylammonium salt of a peroxododecantalic acid was obtained. The molecular mass of this water soluble compound was determined with the ultracentrifuge.

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