Well-defined phosphino-phenolate neutral nickel(ii) catalysts for efficient (co)polymerization of norbornene and ethylene

2015 ◽  
Vol 44 (16) ◽  
pp. 7382-7394 ◽  
Author(s):  
Yan-Ping Zhang ◽  
Wei-Wei Li ◽  
Bai-Xiang Li ◽  
Hong-Liang Mu ◽  
Yue-Sheng Li
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Nickel Catalysts ◽  
Good Solubility ◽  
Highly Efficient

With B(C6F5)3as a singular cocatalyst, a series of phosphino-phenolate neutral nickel catalysts were found to be highly efficient for norbornene (co)polymerization. High molecular weight (co)polymers with good solubility in common organic solvents were obtained.

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

Synthesis and Properties of a High-Molecular-Weight Polyimide Based on 4, 4'-(hexafluoroisopropylidene) Diphthalic Anhydride

2012 ◽  
Vol 550-553 ◽  
pp. 742-746
Author(s):  
Hui Wen Wu ◽  
Hua Li ◽  
He Zhou Liu
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Membrane Separation ◽  
Amic Acid ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Synthesis Parameters ◽  
Soluble Polyimide

A soluble polyimide with high molecular weight was synthesized from 4, 4'-(hexafluoroiso propylidene) diphthalic anhydride (6FDA) and 2, 2’-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (BAPAF) via two-step polycondesation procedure involving the preparation of poly(amic acid) (PAA) followed by chemical imidization. Effect of synthesis parameters on polyimide molecular weight involving material ratio, imidization temperature and imidization catalyst were studied. Synthesized PI was analyzed with respect to their molecular weights, chemical structures and solubility through GPC, FTIR, XRD and solubility tests respectively. The results showed that a high-molecular-weight PI was successfully synthesized from 4, 4'-(hexafluoroisopropylidene) diphthalic anhydride and 2, 2’-bis (3-amino-4-hydroxyphenyl) hexafluoropropane with imidization at 80°C for 3h, material ratio of n(BAPAF):n(6FDA) equal to 1:1 and catalyst of n(triethylamine):n (pyridine) less than1:3. The obtained PI showed excellent solubility in polar aprotic organic solvents such as NMP, DMAc, DMSO, THF and Acetone. Poly(6FDA-BAPAF) PI, with high molecular weight and excellent solubility, which was synthesized under lower imidization temperature that was equal to 80°C,could be easily obtained and convenient to process, thus it is a potential material for membrane separation.

A silole copolymer containing a ladder-type heptacylic arene and naphthobisoxadiazole moieties for highly efficient polymer solar cells

2015 ◽  
Vol 8 (2) ◽  
pp. 552-557 ◽  
Author(s):  
Zhiyun Zhang ◽  
Francis Lin ◽  
Hsieh-Chih Chen ◽  
Hung-Chin Wu ◽  
Chin-Lung Chung ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solar Cells ◽  
High Molecular Weight ◽  
Polymer Solar Cells ◽  
Highly Efficient

We present a silole ladder-type copolymer, PSiNO, with a high molecular weight that affords a remarkable PCE of 8.37%.

scholarly journals The Origin of Chlororganic Compounds in Crude Oil and Oil Fractions

2020 ◽  
Vol 131 (6) ◽  
pp. 3-10
Author(s):  
V. K. Miller ◽  
◽  
D. V. Marochkin ◽  
Yu. G. Noskov ◽  
G. A. Korneeva ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrochloric Acid ◽  
Crude Oil ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Oil Production ◽  
Organochlorine Compounds ◽  
Oil Fractions ◽  
Acid Acid

In this review, published information on the nature and molecular compositions of organochlorine compounds (OCCs), which are found in crude oil and in its refined products, is systematized. The native and added OCCs are reviewed. The formers are concentrated predominantly in high molecular weight resinous-asphaltene substances of crude oil, the latter’s, referred to as light organochlorine compounds, are present in the gasoline fractions. The following chemicals that are used for oil production are regarded as possible sources of OCCs: inhibited hydrochloric acid, acid compounds; organic solvents of asphalt-resin-paraffin deposits, organic solvents served for oil production stimulation, and possible products of a mutual solvent chlorination with hydrochloric acid.

Chloride-promoted Pd-catalyzed direct C–H arylation for highly efficient phosphine-free synthesis of π-conjugated polymers

2015 ◽  
Vol 6 (28) ◽  
pp. 5036-5039 ◽  
Author(s):  
Shotaro Hayashi ◽  
Toshio Koizumi
Keyword(s):  
Molecular Weight ◽  
Conjugated Polymers ◽  
High Molecular Weight ◽  
Efficient Synthesis ◽  
Highly Efficient

We have successfully demonstrated a chloride-promoted Pd-catalyzed phosphine-free direct C–H arylation for highly efficient synthesis of high molecular weight π-conjugated polymers.

Synthesis of high molecular weight polyethylene using iminopyridyl nickel catalysts

2016 ◽  
Vol 52 (58) ◽  
pp. 9113-9116 ◽  
Author(s):  
Shengyu Dai ◽  
Xuelin Sui ◽  
Changle Chen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Nickel Catalysts

Polyethylene with a molecular weight of more than one million could be generated using iminopyridyl nickel catalysts.

scholarly journals Sweetening Pharmaceutical Radiochemistry by18F-Fluoroglycosylation: A Short Review

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Simone Maschauer ◽  
Olaf Prante
Keyword(s):  
Molecular Weight ◽  
Nuclear Medicine ◽  
High Molecular Weight ◽  
Pet Imaging ◽  
Short Review ◽  
Imaging Studies ◽  
Highly Efficient ◽  
High Molecular Weight Proteins

At the time when the highly efficient [18F]FDG synthesis was discovered by the use of the effective precursor 1,3,4,6-tetra-O-acetyl-2-O-trifluoromethanesulfonyl-β-D-mannopyranose (mannose triflate) for nucleophilic18F-substitution, the field of PET in nuclear medicine experienced a long-term boom. Thirty years later, various strategies for chemoselective18F-labeling of biomolecules have been developed, trying to keep up with the emerging field of radiopharmaceutical sciences. Among the new radiochemical strategies, chemoselective18F-fluoroglycosylation methods aim at the sweetening of pharmaceutical radiochemistry by providing a powerful and highly valuable tool for the design of18F-glycoconjugates with suitablein vivoproperties for PET imaging studies. This paper provides a short review (reflecting the literature not older than 8 years) on the different18F-fluoroglycosylation reactions that have been applied to the development of various18F-glycoconjugate tracers, including not only peptides, but also nonpeptidic tracers and high-molecular-weight proteins.

scholarly journals Polymerization of Phenylacetylene-Based Monodendrons with Alkoxy Peripheral Groups and Oxygen/Nitrogen Permeation Behavior of Their Membranes

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Kaneko ◽  
Kazuaki Sato ◽  
Yoshihiko Uchiya ◽  
Masahiro Teraguchi ◽  
Toshiki Aoki
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Focal Point ◽  
Rhodium Catalyst ◽  
Terminal Acetylene ◽  
Permselective Membrane

Monodendron monomers with alkoxy peripheral groups were synthesized, and the focal point of monodendrons, terminal acetylene, was polymerized with rhodium catalyst to yield corresponding polydendrons with a high molecular weight. The polydendrons were soluble in common organic solvents and readily formed membranes. Oxygen permselectivity was improved in the polydendrons with a space-persistent dendritic crowd. It was found that the well-defined dendritic and rod-like structure of the polydendrons was useful for permselective membrane.

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