Copolymerization of 5-norbornene-2-metheneoxy-trimethylsilyl with methyl 5-norbornene-2-carboxylate catalyzed by a novel Ni(benzocyclohexan-ketonaphthylimino)2/B(C6F5)3) system

2012 ◽  
Vol 32 (6-7) ◽  
pp. 415-423
Author(s):  
Xiaofeng Wang ◽  
Xiaohui He ◽  
Defu Chen ◽  
Yiwang Chen
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Nmr Spectra ◽  
Catalyst System ◽  
Narrow Molecular Weight Distribution ◽  
Complex Catalyst ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Catalyst Systems ◽  
C Nmr

Abstract Copolymerization of 5-norbornene-2-metheneoxy-trimethylsilyl [NB-CH2OSi(CH3)3] with norbornene (NB) or methyl 5-norbornene-2-carboxylate (NB-COOCH3) was carried out in toluene by using novel nickel(II) complex catalyst systems, Ni(benzocyclohexan-ketonaphthylimino)2/B(C6F5)3 [Ni(bchkni)2/B(C6F5)3]. The catalyst system showed high activity on the copolymerization of NB-CH2OSi(CH3)3 with NB (2.3–3.3×104 gpolymer/molNi·h) and NB-CH2OSi(CH3)3 with NB-COOCH3(0.5–3.0×104 gpolymer/molNi·h). However, the solubility of copolymers of NB-CH2OSi(CH3)3 with NB and NB-CH2OSi(CH3)3 with NB-COOCH3, which contain 18.7–86.7 mol% of NB-CH2OSi(CH3)3, was too poor to characterize. The achieved copolymers were confirmed to be vinyl-addition copolymers through the analysis of FTIR, 1H NMR, and 13C NMR spectra. The incorporation rate was 8.7–86.7 mol% at a content of 10–90 mol% of the NB-CH2OSi(CH3)3 in the monomer feeds ratios. The obtained ester functionalized NB copolymer containing 8.7–18.7 mol% of NB-CH2OSi(CH3)3 showed a moderate molecular weight (Mw=1.6–6.0×104 g/mol) and relative narrow molecular weight distribution (Mw/Mn=1.6–2.2). Thermogravimetry (TGA) analyses results showed that the copolymers exhibited good thermal stability (Td=330–350°C) and were noncrystalline by WAXD analyses results.

scholarly journals A novel hyperbranched polyester based on 2,2-bis(hydro xylmethyl)butyric acid: synthesis and characterization

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Michelina Soccio ◽  
Lara Finelli ◽  
Nadia Lotti ◽  
Paola Marchese ◽  
Valentina Siracusa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Butyric Acid ◽  
Room Temperature ◽  
Cyanuric Acid ◽  
Acid Synthesis ◽  
Hyperbranched Polyester ◽  
Degree Of Branching ◽  
Good Thermal Stability ◽  
H Nmr ◽  
C Nmr

AbstractA novel hyperbranched polyester was synthesized in bulk from 2,2- bis(hydroxymethyl)butyric acid and two different core molecules (1,1,1-tris- (hydroxylmethyl)propane and 1,3,5-tris(2-hydroxyethyl)cyanuric acid), using ptoluensolfonic acid, scandium trifluoromethanesulfonate, titanium tetrabutoxide and dibutyltin oxide as catalysts and varied reaction temperature and time. At room temperature the samples obtained appeared as glassy, slightly yellow solids, with Mn (calculated by 1H-NMR spectra) in the range 500 - 2000. The degree of branching of the polyesters was determined by 13C-NMR spectroscopy and was found in the range 0.32 - 0.53. The introduction of the monomer in various steps seems to influence slightly the degree of branching, but has no effect on the molecular weight of these polymers. The polyesters exhibited a good thermal stability, as revealed by TGA technique, and the glass transition temperature, determined by DSC, was found to depend on the molecular weight and the kind of catalyst employed.

Synthesis and Optical Properties of Dipolar Thiazole Derivatives Incorporating Nitro and Amino Substituents

2018 ◽  
Vol 773 ◽  
pp. 157-161
Author(s):  
Ahmad Shah Noor Aisyah ◽  
Nur Farahin Pairan ◽  
Noor Azilah Mohd Kasim ◽  
Bohari Mohd Yamin
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Electron Acceptor ◽  
Decomposition Temperature ◽  
Amino Group ◽  
Thiazole Derivatives ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Ft Ir ◽  
C Nmr

We report the synthesis of two dipolar thiazole derivatives functionalized with nitro group as electron acceptor and amino group as electron donor, in order to study their optical properties in the UV-vis range. Their structures were verified by 1H NMR, 13C NMR, HRMS and FT-IR. The resulted thiazole derivatives have good thermal stability with decomposition temperature, Td of 320.20 °C and 284 °C for compounds 1 and 2 respectively. The absorbance bands of compound 2 in the UV-vis range are more red-shifted than that of compound 1 which made compound 2 could have high potential as a great organic NLO material.

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

1995 ◽  
Vol 60 (4) ◽  
pp. 619-635 ◽  
Author(s):  
Václav Křeček ◽  
Stanislav Hilgard ◽  
Miloš Buděšínský ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Coupling Constants ◽  
Side Chain ◽  
Oxidation Reactions ◽  
H Nmr ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Intramolecular Association ◽  
C Nmr

A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1H NMR, 13C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1H and 13C NMR spectra are discussed.

THE EXTRACTION OF ORGANIC MATTER FROM SELECTED SOILS AND PARTICLE SIZE FRACTIONS WITH 0.5 M NaOH AND 0.1 M Na4P2O7 SOLUTIONS

1989 ◽  
Vol 69 (2) ◽  
pp. 253-262 ◽  
Author(s):  
M. SCHNITZER ◽  
P. SCHUPPLI
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acids ◽  
Nmr Spectra ◽  
Attractive Alternative ◽  
Particle Size Fractions ◽  
Molecular Weights ◽  
Naoh Solution ◽  
C Nmr ◽  
Medium Silt

Organic matter (OM) in the Bainsville and Melfort soils, and in coarse clay and medium silt fractions separated from these soils, was extracted under N2 with 0.5 M NaOH and unadjusted 0.1 M Na4P2O7 solutions. pH ranges of the soils and fractions in contact for 24 h with 0.5 M NaOH and 0.1 M Na4P2O7 solutions extended from 12.2 to 12.6 and 9.0 to 9.4, respectively. Slightly greater proportions of the soil-carbon were extracted by 0.5 M NaOH than by 0.1 M Na4P2O7 solution. The differences, however, did not appear to be significant and may vary from soil to soil. The efficiency of extraction and the characteristics of the extracted materials were assessed on humic acids (HAs), which were isolated from the extracts. From the Bainsville soil and fractions, 0.1 M Na4P2O7 solution extracted more high-molecular weight and more deeply colored HAs than did 0.5 M NaOH solution. But HAs extracted from the Melfort soil and fractions had similar molecular weights and colours. 13C NMR spectra showed that HAs extracted by 0.1 M Na4P2O7 solution tended to be more aromatic than HAs extracted by 0.5 M NaOH solution. Well defined solid-state 13C NMR spectra of HAs, containing up to 69.0% ash, could be recorded. Unadjusted 0.1 M Na4P2O7 solution under N2 was found to be an attractive alternative to 0.5 M NaOH solution as an extractant for soil OM. Key words: Humic acids, E4:E6 ratios, IR spectra, 13C NMR spectra, aromaticity

Semi-bio-based aromatic polyamides from 2,5-furandicarboxylic acid: toward high-performance polymers from renewable resources

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87013-87020 ◽  
Author(s):  
Kaiju Luo ◽  
Yan Wang ◽  
Junrong Yu ◽  
Jing Zhu ◽  
Zuming Hu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Renewable Resources ◽  
High Performance ◽  
Good Thermal Stability ◽  
Aromatic Polyamides ◽  
High Performance Polymers ◽  
Furandicarboxylic Acid

Aromatic furanic polyamides with relatively high molecular weight were synthesized, and good thermal stability and mechanical properties were demonstrated.

scholarly journals A Natural Triglyceride from the Methanol Root Extract of Cyphostemma Adenocaule (Steud. Ex A. Rich.) Wild & R.B.Drumm

2020 ◽  
Author(s):  
Abdulbasit Haliru Yakubu ◽  
Iliya Ibrahim ◽  
Abdulqadir bukar bababe ◽  
Hassan Yesufu ◽  
mohammed Garba Tom
Keyword(s):  
Mobile Phase ◽  
Nmr Spectra ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Solvent System ◽  
Root Extract ◽  
H Nmr ◽  
Signal Peak ◽  
Methylene Group ◽  
C Nmr

<p><i>Cyphostemma adenocaule </i>(Steud. ex A. Rich.) is one of the specie plant that belongs to the family vitacea. In this study, Trilinolein was isolated and characterized from the methanol root extract of the plant. Column chromatography over silica gel granules as the stationary phase and eluted with a mobile phase mixture of n-Hex-EtA; EtA-CHCL3 and CHCL<sub>3</sub>-MeOH with gradient increasing polarity, followed by a second column using saphadex-LH20 and 100% MeOH as stationary and mobile phase vehicle respectively. TLC was developed with EtA 15: CHCL3<sub> </sub>8: MeOH 4: H<sub>2</sub>O 1 as solvent system; sprayed with 10% H<sub>2</sub>SO<sub>4 </sub>,Vanillin-sulphuric acid, and/ or Polyethylene glycol PEG and heat for spot detection and confirmation of bioactive principles. Compound CA1 was obtained and purified with CHCL3 to give a yellow semi-solid compound (0.23g). The <sup>1</sup>H-NMR spectra showed 9 different signals; a signal peak of a glycerol (-C<b>H<sub>2</sub></b>OCOR-) moiety on the first α-C chain and on the third αʹ-C at 4.143-4.187ppm and 4.296-4.325ppm respectively, while that of a β glycerol (-C<b>H</b>COR-) at 5.286ppm. Signals of an allylic methylene group at 2.023-2.035ppm, Olefenic hydrogen group at signal peak of 5.362ppm and a diallylic methylene group at signal 2.790ppm were also observed. In the <sup>13</sup>C NMR spectra of compound CA1, 57 carbon atoms where observed, multiple signals overlapping at a range of 14.13-34.21ppm corresponding to the aliphatic CH3 (<b>C18</b>), CH2 (<b>C2, C3, C4, C5, C6, C7, C15, C16, and C17</b>) and allylic (<b>C8, C14</b>) carbon atoms. Signals at 127.90-130.24ppm were assigned to the olefienic C atoms (<b>C9, C10, C12</b>, and <b>C13</b>) while signal of 172.87ppm and 173.32ppm were assigned to the carbonyl (<b>C</b>=O) carbon atoms (<b>C1 </b>and<b> C2</b>) respectively (Table 2). </p> <p>Analysis with DEPT-135, H-H COSY, HMBC and HSQC assignments of CA1 augments assignment of signals made for CA1 from <sup>1</sup>H-NMR and <sup>13</sup>C-NMR and corresponded to that of Trilinolein <u>(<a href="https://pubchem.ncbi.nlm.nih.gov/#query=C57H98O6">C<sub>57</sub>H<sub>98</sub>O<sub>6</sub></a>, </u>MW 879.4 g/mol). The isolated compound was positive for the acrolein test for triglycerides; fat & oil and had an IC<sub>50</sub> of 46.08µg/ml radical scavenging activity.</p>

scholarly journals Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

2018 ◽  
Vol 14 ◽  
pp. 3011-3017
Author(s):  
Akın Sağırlı ◽  
Yaşar Dürüst
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Synthetic Route ◽  
X Ray ◽  
H Nmr ◽  
2D Nmr Spectra ◽  
Tof Ms ◽  
C Nmr

The present work describes an unfamiliar reaction of 5-(chloromethyl)-3-substituted-phenyl-1,2,4-oxadiazoles with KCN affording trisubstituted 1,2,4-oxadiazol-5-ylacetonitriles and their parent alkanes, namely, 1,2,3-trisubstituted-1,2,4-oxadiazol-5-ylpropanes. To the best of our knowledge, the current synthetic route leading to decyanated products will be the first in terms of a decyanation process which allows the transformation of trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title compounds were identified by means of IR, 1H NMR, 13C NMR, 2D NMR spectra, TOF–MS and X-ray measurements.

Synthesis and Characterization of Low Content of Structural Defects of Aryl-Substituted Electroluminescent Poly(p-phenylenevinylene)s

2001 ◽  
Vol 665 ◽  
Author(s):  
Zhi-Kuan Chen ◽  
Nancy Hoi Sim Lee ◽  
Wei Huang
Keyword(s):  
Thermal Stability ◽  
Quantum Efficiency ◽  
Defect Structure ◽  
Main Chain ◽  
Structural Defects ◽  
Synthesis And Characterization ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Polymer Main Chain

ABSTRACTWe report the synthesis and characterization of a novel series of aryl-substituted PPVs, which have shown excellent processability, good thermal stability, high photoluminescence quantum efficiency and low content of structural defects. The substituents of the polymers were designed with different degree of hindrance effect on the main chain. 1H NMR measurement indicates that the defect structure in the polymer main chain can be effectively depressed by introducing bulk and hindrance substituents.

scholarly journals New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

2007 ◽  
Vol 62 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Stephan W. Kohl ◽  
Katharina Kuse ◽  
Markus Hummert ◽  
Herbert Schumann ◽  
Clemens Mügge ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Nmr Spectra ◽  
Acid Ethyl Ester ◽  
Affinity Tags ◽  
X Ray ◽  
H Nmr ◽  
Synthetic Routes ◽  
New Compounds ◽  
C Nmr

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.

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