Synthesis and properties of biobased copolyamides based on polyamide 10T and polyamide 56 through one-pot polymerization

2021 ◽  
Author(s):  
TianHao Ai ◽  
Guangji Zou ◽  
Wutong Feng ◽  
Zhonglai Ren ◽  
Fei Li ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Melting Behavior ◽  
Wide Angle ◽  
Polycondensation Reaction ◽  
One Pot

A series new biobased polyamide 10T-co-56 are synthesized with various comonomer composition by one-pot polycondensation reaction and investigated their structures, crystalline and melting behavior by using 1H-NMR spectroscopy, wide angle...

A Three Component Metalloporphyrin Assembly

2004 ◽  
Vol 57 (1) ◽  
pp. 29 ◽  
Author(s):  
Steven J. Langford ◽  
Vei-Lin Lau
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Self Assembly ◽  
1H Nmr Spectroscopy ◽  
Structural Motif ◽  
One Pot ◽  
Pyridyl Group ◽  
Component System

A novel dialkylammonium salt 1 · PF6, bearing a pyridyl group, has been employed as a structural motif for the efficient one-pot self-assembly of a three-component system comprising dibenzo-[24]crown-8, 1 · PF6, and zinc(II) 5,10,15,20-tetraphenylporphyrin. The resulting metalloporphyrin assembly has been characterized in solution by 1H NMR spectroscopy and ESIMS and serves as a model to more elaborate multichromophoric systems.

scholarly journals Synthesis of ester-siloxane multiblock copolymers

2004 ◽  
Vol 58 (11) ◽  
pp. 499-504
Author(s):  
Vesna Antic ◽  
Marija Vuckovic ◽  
Milutin Govedarica
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Multiblock Copolymers ◽  
Polycondensation Reaction ◽  
Two Stage ◽  
End Groups

It was shown that the two-stage transesterification/polycondensation reaction in the melt, can successfully be applied for the preparation of poly(butylene terephtalate-dimethylsiloxane) multiblock copolymers. Three series of co-polymers were synthesized, using poly(dimethylsiloxanes) bearing ester (two series) and hydroxy -end groups as reactants. The structure and composition of the obtained copolymers were determined by 1H NMR spectroscopy A mechanism, i.e. an order of reaction steps, involved in the preparation of the copolymers, was suggested.

Asymetrical Dimer - allyl-palladiu Complexes II. Data from Infrared Spectra and Chemical Behaviour

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Maria Maganu ◽  
Filip Chiraleu ◽  
Constantin Draghici ◽  
Gheorghe Mihai
Keyword(s):  
Carbon Monoxide ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Infrared Spectra ◽  
Analytical Methods ◽  
1H Nmr Spectroscopy ◽  
Chemical Behaviour ◽  
The Asymmetry ◽  
Pd Complexes

The previous data obtained by 1H-NMR spectroscopy established the existence of an asymmetry of the bond between Pd and p-allylic groups, even in the p-allyl-Pd complexes dimers which are considered usually symmetric dimers. The asymmetry of the bond depends by the substitutes of the allylic group. Other analytical methods were investigated for additional proof of the obtained results. Thus, this paper discusses how this asymmetry would be reflected in the infrared spectra and in the reaction of the complexes with carbon monoxide.

Diastereoselective Reduction of Selected α-substituted β-keto Esters and the Assignment of the Relative Configuration by 1H-NMR Spectroscopy

2020 ◽  
Vol 07 ◽  
Author(s):  
Christian Trapp ◽  
Corinna Schuster ◽  
Chris Drewniok ◽  
Dieter Greif ◽  
Martin Hofrichter
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Selective Reduction ◽  
Reducing Agents ◽  
Relative Configuration ◽  
Curtius Rearrangement ◽  
Keto Esters ◽  
Hydroxy Esters ◽  
Diastereoselective Reduction

Background:: Chiral β-hydroxy esters and α-substituted β-hydroxy esters represent versatile building blocks for pheromones, β-lactam antibiotics and 1,2- or 1,3-aminoalcohols. Objective:: Synthesis of versatile α-substituted β-keto esters and their diastereoselective reduction to the corresponding syn- or anti-α-substituted β-hydroxy esters. Assignment of the relative configuration by NMR-spectroscopy after a CURTIUS rearrangement of α-substituted β-keto esters to 4-substituted 5-methyloxazolidin-2-ones. Method:: Diastereoselective reduction was achieved by using different LEWIS acids (zinc, titanium and cerium) in combination with complex borohydrides as reducing agents. Assignment of the relative configuration was verified by 1H-NMR spectroscopy after CURTIUS-rearrangement of α-substituted β-hydroxy esters to 4-substituted 5-methyloxazolidin-2-ones. Results:: For the syn-selective reduction, titanium tetrachloride (TiCl4) in combination with a pyridine-borane complex (py BH3) led to diastereoselectivities up to 99% dr. High anti-selective reduction was achieved by using cerium trichloride (CeCl3) and steric hindered reducing agents such as lithium triethylborohydride (LiEt3BH). After CURTIUS-rearrangement of each α-substituted β-hydroxy ester to the corresponding 4-substituted 5-methyloxazolidin-2-one, the relative configuration was confirmed by 1H NMR-spectroscopy. Conclusion:: We have expanded the procedure of LEWIS acid-mediated diastereoselective reduction to bulky α-substituents such as the isopropyl group and the electron withdrawing phenyl ring.

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

Detecting and Differentiating Monosaccharide Enantiomers by 1H NMR Spectroscopy

2021 ◽  
Author(s):  
Masanori Inagaki ◽  
Risa Iwakuma ◽  
Susumu Kawakami ◽  
Hideaki Otsuka ◽  
Harinantenaina L. Rakotondraibe
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy
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