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

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

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.

Reactions of Sodium N,N-Diethyldithiocarbamate with the Chlorides and Bromides of Niobium(V), Tantalum(V), and Protactinium(V)

1971 ◽  
Vol 49 (8) ◽  
pp. 1151-1160 ◽  
Author(s):  
P. R. Heckley ◽  
D. G. Holah ◽  
D. Brown
Keyword(s):  
Electrical Conductivity ◽  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Organic Solvents ◽  
Conductivity Measurements ◽  
Nuclear Magnetic

Reactions between niobium(V), tantalum(V), and protactinium(V) chlorides and bromides and sodium N,N-diethyldithiocarbamate (Nadtc) have been examined in non-aqueous, non-oxygenated organic solvents. Complexes obtained are of the types Mdtc4X, Mdtc3X2, Mdtc3S, Mdtc2X3, and Mdtc2X3.nC6H6 (n = 0.7–1.0); not all complexes have been isolated for each metal. Within each group the niobium(V) and tantalum(V) complexes are isostructural; possible structures are discussed in the light of results from infrared (i.r.) and nuclear magnetic resonance (n.m.r.) spectra, molecular weight, and electrical conductivity measurements.

Synthesis, Characterization and Properties of Conjugated Poly(1-Alkyl-2,5-Pyrrylene Vinylene)

1997 ◽  
Vol 488 ◽  
Author(s):  
In Tae Kim ◽  
Ronald L. Elsenbaumer
Keyword(s):  
Molecular Weight ◽  
Conjugated Polymers ◽  
Band Gap ◽  
Organic Solvents ◽  
Optical Band Gap ◽  
Vis Spectroscopy ◽  
Electrical Conductivities ◽  
C Nmr

AbstractA series of poly(N-alkylpyrrylene vinylenes)( alkyl = methyl(l), hexyl(2), dodecyl(3)) have been synthesized from the monomer, N-alkyl-2,5-bis(thiophenylmethylene)pyrrole, by base induced elimination and polymerization. The resulting deep purple conjugated polymers (2, 3) were soluble in a variety organic solvents. The electrical conductivities of the polymers lie in the range, 10−2 to 2.5 S/cm. The highest yield was obtained when the polymers were synthesized in refluxing THF with a monomer/ base mole ratio of 1/4. The optical band gap of the undoped polymers were 1.89 eV(1), 1.69 eV(2) and 1.65 eV(3). Characterization of the polymers includes IR, CV, 1H and 13C NMR, UV-vis spectroscopy, TGA and molecular weight studies.

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