13C NMR Characterization of Polychloroprene Microstructure I. Spectral Assignments

1977 ◽  
Vol 50 (1) ◽  
pp. 49-62 ◽  
Author(s):  
M. M. Coleman ◽  
D. L. Tabb ◽  
E. G. Brame
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Quantitative Data ◽  
Nmr Relaxation ◽  
13C Nmr Spectroscopy ◽  
Nmr Characterization ◽  
Relaxation Studies ◽  
Structural Irregularities ◽  
Near Future

Abstract 13C NMR spectroscopy has proved to be a very powerful tool for the characterization of polychloroprene microstructure. We have identified and assigned the lines associated with diad and triad sequences involving the predominant trans-1,4 placement, together with other lines associated with cis-1,4, 1,2, isomerized 1,2, and 3,4 structural irregularities. Currently, we are performing 13C NMR, relaxation studies on the chloroprene polymers and will be presenting quantitative data in the near future.

scholarly journals CARBOXYMETHYLATION OF POLYSACCHARIDES – A COMPARATIVE STUDY

2020 ◽  
Vol 54 (9-10) ◽  
pp. 835-844
Author(s):  
GABRIEL LARS ◽  
ANTJE TIED ◽  
THOMAS HEINZE
Keyword(s):  
Nmr Spectroscopy ◽  
Caustic Soda ◽  
Comparative Study ◽  
13C Nmr ◽  
Reaction Medium ◽  
13C Nmr Spectroscopy ◽  
Water Soluble

The present study describes the heterogeneous carboxymethylation of xylan,α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose with sodium monochloracetate (SMCA) using iso-propanol as slurry medium in the presence of caustic soda. Using heteropolysaccharides for the carboxymethylation, higher DS values are obtained compared to the DS of homopolysaccharides. The influence of the amount caustic soda in the reaction medium is studied. The characterization of the products obtained is performed by means of 13C-NMR spectroscopy. Carboxymethylation transforms the investigated polysaccharides into water-soluble products.

Characterization of cellulose and cellulose derivatives in solution by high resolution 13C-NMR spectroscopy

1994 ◽  
Vol 19 (1) ◽  
pp. 29-78 ◽  
Author(s):  
Irene Nehls ◽  
Wolfgang Wagenknecht ◽  
Burkart Philipp ◽  
Dorothea Stscherbina
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Cellulose Derivatives

13C NMR Characterization of Polychloroprene Microstructure II. Relaxation, NOE, and Quantitative Measurements

1978 ◽  
Vol 51 (4) ◽  
pp. 668-676 ◽  
Author(s):  
M. M. Coleman ◽  
E. G. Brame
Keyword(s):  
Free Radical ◽  
Spin Relaxation ◽  
13C Nmr ◽  
Quantitative Measurements ◽  
Nmr Characterization ◽  
Infrared Studies ◽  
Excellent Method ◽  
Quantitative Results ◽  
Structural Irregularities

Abstract Spin relaxation, NOE, and quantitative measurements have been performed on chloroprene polymers prepared by free radical techniques in the range −150 to +90°C. 13C NMR has proved to be an excellent method for the characterization of polychloroprene microstructure. From our quantitative results it would appear that the concentration of cis-1,4 structural irregularities has been considerably overestimated in previous infrared studies. In addition, the relative amount of trans-1,4 inversions (HT) appears to be somewhat higher than previously reported.

scholarly journals Synthesis and Characterization of New Silver (I) N-Heterocyclic Ccarbene Ccomplex Dderived from Imidazol-2-ylidene salt

2018 ◽  
Vol 28 (2) ◽  
pp. 55
Author(s):  
Mohammedl Mujbe Hasson
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Room Temperature ◽  
13C Nmr Spectroscopy ◽  
Synthesis And Characterization ◽  
Imidazolium Salt ◽  
In Situ Method

A new N, N'-imidazolium salt 1-(2,6-diisopropylphenyl)-3- (4,6-dimorpholino -1,3,5-traizine-2-yl)-1H-imidazol-3-ium chloride) as a precursor of N - heterocyclic carbene ligand was prepared via the reaction of 1 - (2, 6 - diisopropyl phenyl - 1H - imidazole) with 1, 3, 5 - triazine derivative bearing morpholine substituent (2, 6 -dimorpholine - 6- chloro-1, 3, 5-triaziazine). Linear coordi-nated Ag (І) NHC complex was synthesised via deprotonation of the imidazolium salt and reac-tion with Ag2O in darkness at room temperature by in situ method. The complex was synthesised for using as transfer agent to prepare another transition metals complexes by transmetallation method in the future. The imidazolium salt and their silver complex have been characterized by 1 H and 13C NMR spectroscopy as well as mass spectrometry.

Sign in / Sign up

Export Citation Format

Share Document