scholarly journals Synthesis of Soluble Novel Polyacetylenes Containing Carbamate and Eugenol Moieties

2020 ◽  
Vol 20 (4) ◽  
pp. 818
Author(s):  
Erwin Abdul Rahim
Keyword(s):  
Molecular Weight ◽  
Organic Solvents ◽  
Helical Structure ◽  
High Yield

This study was aimed to synthesize a series of novel polyacetylenes containing carbamate and eugenol moieties. The polymerization of 1-(3,4-dimethoxyphenyl) propane-2-yl prop-2-ynylcarbamate (1), 1-(3,4-dimethoxyphenyl)propane-2-yl 3-ethynyl phenylcarbamate (2), 1-(3,4-dimethoxyphenyl)propane-2-yl 4-ethynylphenylcarbamate (3), (2S)-1-(3,4-dimethoxyphenyl)propane-2-yl 2-((prop-2ynyloxy)carbonylamino)propanoate (4) in the presence of (nbd)Rh+[ɳ6-C6H5B–(C6H5)3] as catalyst have successfully produced corresponding polyacetylenes [poly(1)–poly(4)] in high yield. The molecular weight of the synthesized polyacetylenes ranged between 13,900–18,400 g/mol. In particular, the molecular weight of poly(1) could be increased by the addition of menthol. Practically, these polymers were found to have a stable helical structure and soluble in common organic solvents.

scholarly journals [Rh(L-alaninate)(1,5-Cyclooctadiene)] Catalyzed Helix-Sense-Selective Polymerizations of Achiral Phenylacetylenes

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1223 ◽  
Author(s):  
Qingyu Wang ◽  
Hongge Jia ◽  
Yongqiang Shi ◽  
Liqun Ma ◽  
Guoxing Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Main Chain ◽  
Helical Structure ◽  
Active Species ◽  
Rhodium Complex ◽  
High Yield ◽  
Hydroxyl Groups ◽  
High Catalytic Activity ◽  
Chiral Amine ◽  
Polymer Main Chain

The [Rh(L-alaninate)(cod)] (cod = 1,5-Cyclooctadiene) complex was synthesized and characterized. Asymmetric polymerizations of achiral phenylacetylene with two hydroxyl groups and a dodecyl group (DoDHPA) were performed by using the rhodium complex as the catalyst to provide polymers with a higher molecular weight (>105) than the polymers obtained using the [Rh(cod)Cl]2 initiator systems. The resulting polymers showed circular dichroism (CD) signals at approximately 310 and 470 nm, indicating that they have a preferential one-handed helical structure. The helix sense in the polymer main chain was controlled by the sign of the catalyst chirality. These findings suggest that the rhodium complex with a chiral amine is the true active species for the helix-sense-selective polymerization of DoDHPA. The [Rh(L-alaninate)(cod)] complex also exhibits high catalytic activity in the polymerization of phenylacetylene (PA) to give a high yield and molecular weight. All these results demonstrate that this Rh complex is an excellent catalyst for the polymerization of phenylacetylene monomers.

Effects of the Molecular Weight of PCz on Selective Extraction of Large-Diameter Semiconducting Single-Walled Carbon Nanotubes

2021 ◽  
Vol 69 ◽  
pp. 11-21
Author(s):  
Ping Zhang ◽  
Wen Hui Yi ◽  
Bai Lei ◽  
Jin Feng Zhou ◽  
Yi Long Tian ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Weight ◽  
Arc Discharge ◽  
Large Diameter ◽  
Single Walled Carbon Nanotubes ◽  
Selective Extraction ◽  
High Yield ◽  
Extraction Technology ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Due to the difficulty in the selective synthesis of semiconductor (s-) and metal (m-) single-walled carbon nanotubes (SWCNTs), we still need to explore the selective extraction technology of s-SWCNTs. Using Poly[9-(1-octylonoyl)-9H-carbazole-2,7-diyl] (PCz) extraction of s-SWCNTs has attracted extensive attention in recent years, because it can selective extraction of large-diameter s-SWCNTs with high purity. However, influence of the molecular weight of this polymer on the s-SWCNTs selective extraction properties remains unclear. In this study, we used PCz with different average molecular weights to study the ability of selective extraction s-SWCNTs from pristine arc discharge carbon nanotubes. Spectra studies indicate that compared to the PCz with lower molecular weight, the PCz with higher molecular weight has better selective extraction ability, and can help to obtain s-SWCNTs with higher purity (>99%) and high yield. FETs devices have been prepared by s-SWCNTs obtained via PCz with higher molecular weight exhibit higher on/off ratio, lower off current and lower subthreshold swing. This work offers a reference of the design and synthesis of PCz polymer that performs sufficient selective ability in extracting s-SWCNTs with promising applications.

Pteridine derivatives: novel low-molecular-weight organogelators and their piezofluorochromism

2020 ◽  
Vol 44 (8) ◽  
pp. 3382-3391
Author(s):  
Shenzheng Xu ◽  
Xiaoyu Jia ◽  
Jiaxin Lu ◽  
Lianyou Zheng ◽  
Kuo Lv ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Solvents ◽  
Low Molecular Weight ◽  
Self Assembling ◽  
Conjugated Compounds ◽  
Low Molecular Weight Organogelators ◽  
Pteridine Derivatives

Here, π-conjugated compounds based on pteridine derivatives were synthesized and their self-assembling behaviors in a variety of organic solvents and piezofluorochromism were studied.

Isolation of the virus inhibitor from the root extract of Boerhaavia diffusa inducing systemic resistance in plants

1979 ◽  
Vol 57 (11) ◽  
pp. 1214-1217 ◽  
Author(s):  
H. N. Verma ◽  
L. P. Awasthi ◽  
K. C. Saxena
Keyword(s):  
Molecular Weight ◽  
Organic Solvents ◽  
Preliminary Analysis ◽  
Antiviral Agent ◽  
Systemic Resistance ◽  
Partial Purification ◽  
Root Extract ◽  
Virus Inhibitor ◽  
Boerhaavia Diffusa

An antiviral agent, active against spherical and tubular viruses in hypersensitive and systemic hosts, has been isolated from the roots of Boerhaavia diffusa. Partial purification of inhibitor by organic solvents, Sephadex gel, and protein precipitants has been achieved. Preliminary analysis indicates that the inhibitor may be a glycoprotein with a molecular weight of 16 000–20 000 daltons.

scholarly journals Isolation of High-Molecular-Weight DNA Using Organic Solvents

2017 ◽  
Vol 2017 (4) ◽  
pp. pdb.prot093450 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
High Molecular Weight Dna

scholarly journals Two-step affinity-chromatographic purification of cathepsin D from pig myometrium with high yield

1981 ◽  
Vol 197 (2) ◽  
pp. 519-522 ◽  
Author(s):  
E G Afting ◽  
M L Recker
Keyword(s):  
Molecular Weight ◽  
Concanavalin A ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Cathepsin D ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Yield ◽  
Acid Proteinase ◽  
Chromatographic Purification

Cathepsin D was purified by two-step affinity chromatography on concanavalin A- and pepstatin-Sepharose. The main purification was achieved by washing the enzyme bound to the pepstatin-Sepharose column with buffered 6 M-urea. This step separated cathepsin D from all low- and high-molecular-weight impurities. Although the 1700-fold purified acid proteinase was homogeneous on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, it still showed microheterogeneity.

Measurement of Molecular Weight in Organic Solvents

1951 ◽  
Vol 23 (7) ◽  
pp. 947-949 ◽  
Author(s):  
G. B. Taylor ◽  
M. B. Hall
Keyword(s):  
Molecular Weight ◽  
Organic Solvents
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