scholarly journals Kinetics of radical telomerization of acrylic acid in the presence of 1-octadecanethiol

2018 ◽  
Vol 90 (11) ◽  
pp. 1743-1754 ◽  
Author(s):  
Yaroslav O. Mezhuev ◽  
Oksana Y. Sizova ◽  
Yuri V. Korshak ◽  
Anna L. Luss ◽  
Ivan V. Plyushchii ◽  
...  
Keyword(s):  
Critical Micelle Concentration ◽  
Acrylic Acid ◽  
Monomer Concentration ◽  
Atom Economy ◽  
Exponential Factor ◽  
H Nmr ◽  
Radical Telomerization ◽  
Kinetics Of ◽  
End Group ◽  
C Nmr

AbstractThe oligomer of acrylic acid with a thiooctadecyl end-group was obtained by using octadecyl mercaptan as the chain-transfer agent. The resulting oligomer was characterized by 1H NMR and 13C NMR spectroscopy and critical micelle concentration was determined in aqueous solution. The order with respect to the initiator concentration was 0.5 and 1.6 with respect to the monomer concentration. The abnormal reaction order with respect to the monomer concentration was explained by participation in the chain propagation of unassociated and associated forms of acrylic acid, which were stabilized by formation of hydrogen bonds. The kinetic parameters of telomerization were determined. Telomerization with acrylic acid in the non-associated form had lower activation energy and lower pre-exponential factor than in the case of associated forms. The synthesis of the acrylic acid oligomer with a thiooctadecyl end-group having a low critical micelle concentration in water was carried out in one stage and corresponds to the concept of atom economy.

scholarly journals Kinetics of Free Radical Polymerization of N-Substituted Amides and Their Structural Implications

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Anca Aldea ◽  
Ana-Maria Albu ◽  
Alina Nicolescu ◽  
Victorita Tecuceanu
Keyword(s):  
Hydrogen Bonding ◽  
Free Radical ◽  
Nitrogen Atom ◽  
Steric Hindrance ◽  
Solvent Polarity ◽  
Hydrogen Bonding Interaction ◽  
H Nmr ◽  
Bonding Interaction ◽  
Kinetics Of ◽  
C Nmr

Two N-substituted amides (N-acryloyl morpholine and N-methyl-N-vinylacetamide) were polymerized in different solvents using radical initiator. The tacticity of obtained polymers was determined by 400 MHz1H-NMR and13C-NMR. At a given temperature, the syndiotacticity increased with increasing the solvent polarity. This solvent effect may be related to the hydrogen bonding interaction among solvent, monomer, and/or growing species. A peculiar aspect regards the steric hindrance at the nitrogen atom.

α- and β-Cyclodextrin [2]rotaxanes with (diethylenetriamine)platinum(II) stoppers

2005 ◽  
Vol 83 (12) ◽  
pp. 2091-2097 ◽  
Author(s):  
Victor X Jin ◽  
Donal H Macartney ◽  
Erwin Buncel
Keyword(s):  
Self Assembly ◽  
Electrospray Mass Spectrometry ◽  
Platinum Complexes ◽  
H Nmr ◽  
Bridging Ligand ◽  
Dinuclear Platinum ◽  
End Groups ◽  
Group A ◽  
Kinetics Of ◽  
End Group

A series of dinuclear platinum(II) complexes, [(dien)Pt(NH2(CH2)nNH2)Pt(dien)]Cl4 (dien = diethylenetriamine, n = 8, 9, 10, and 12) and their corresponding [2]rotaxanes with α-cyclodextrin (α-CD), [(dien)Pt{NH2(CH2)nNH2·α-CD}Pt(dien)]Cl4, have been synthesized and characterized by 1H, 13C, and 195Pt NMR spectroscopy and electrospray mass spectrometry. The rotaxanes were prepared by reacting the {NH2(CH2)nNH2·α-CD} pseudorotaxanes with [Pt(dien)]Cl, to stopper the included linear α,ω-diaminoalkane chains with the inert Pt(II) end groups. The kinetics of the self-assembly and dissociation of the β-CD rotaxane, [(dien)Pt{NH2(CH2)10NH2·β-CD}Pt(dien)]4+, were investigated by using 1H NMR and are indicative of a slippage mechanism, owing to the comparable sizes of the β-CD cavity and the [Pt(dien)]+ end group. A relatively weak inclusion of the end group in the β-CD cavity precedes a thermally promoted passage of the β-CD over the [Pt(dien)]+ end group onto the hydrophobic polymethylene chain of the bridging ligand of the thread. Key words: rotaxanes, pseudorotaxanes, cyclodextrin, platinum complexes, slippage mechanism.

scholarly journals Novel silane based cross-linkers for preparation of methyl methacrylate gels

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Javaherian Naghash Hamid ◽  
Mir Garshasb
Keyword(s):  
Methyl Methacrylate ◽  
Structural Characteristics ◽  
Monomer Concentration ◽  
Weight Fraction ◽  
Gel Point ◽  
H Nmr ◽  
Total Monomer Concentration ◽  
Type C ◽  
Cross Linker ◽  
C Nmr

Abstract(2,2'-(Dimethylsilanediyl)bis(oxy)bis(ethane-1,2-diyl)bis(2-methylacrylate) (Type A cross-linker), (2,2'-(methyl) (phenyl) silanediyl)bis(oxy) bis (ethane-1,2- diyl)bis(2-methylacrylate)) (Type B cross-linker), and (2,2'-(diphenylsilanediyl)bis (oxy)bis(ethane-1,2-diyl)bis(2-methylacrylate)) (Type C cross-linker) three novel cross-linkers, (divinyl monomers), containing silanes and two methacrylates group (Si-DVM) were prepared by the condensation of 2-hydroxyethyl methacrylate (HEMA) with dichlorodimethyl, (DCDM) dichloromethyl phenyl (DCMP) and dichlorodiphenyl silane (DCDPS) in the presence of triethylamine (TEA). With these cross-linkers, methyl methacrylate, (MMA) can copolymerize by free-radical cross-linking copolymerization in toluene at a total monomer concentration of 3 molL-1 and at 70 °C. The experimental results show that increasing of Si-DVM concentration resulted in a decrease in gel point and swelling degree and an increase in conversion percent and weight fraction of the gels. The obtained crosslinkers were characterized by 1H-NMR and 13C-NMR spectroscopy and structural characteristics of the gels were examined by using equilibrium swelling in toluene solvent, gel fraction and Fourier-transform infrared (FTIR) analysis. The morphology of the copolymers was also investigated by Scanning electron microscopy (SEM).

scholarly journals Effect of transfer agent, temperature and initial monomer concentration on branching in poly(acrylic acid): A study by 13 C NMR spectroscopy and capillary electrophoresis

Polymer ◽  
2017 ◽  
Vol 114 ◽  
pp. 209-220 ◽  
Author(s):  
Jean-Baptiste Lena ◽  
Alexander K. Goroncy ◽  
Joel J. Thevarajah ◽  
Alison R. Maniego ◽  
Gregory T. Russell ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Nmr Spectroscopy ◽  
Acrylic Acid ◽  
Monomer Concentration ◽  
Initial Monomer Concentration ◽  
Initial Monomer ◽  
C Nmr ◽  
Poly Acrylic Acid

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.

Synthesis of 2-amino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-thiazines

1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč
Keyword(s):  
Spectral Data ◽  
Chlorine Atom ◽  
Mass Spectra ◽  
High Reactivity ◽  
Secondary Amines ◽  
Dimroth Rearrangement ◽  
H Nmr ◽  
New Synthesis ◽  
C Nmr

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.

Oxynemorensine, an alkaloid from Senecio nemorensis L., var. subdecurrens GRISEB

1980 ◽  
Vol 45 (2) ◽  
pp. 548-558 ◽  
Author(s):  
Antonín Klásek ◽  
Petr Sedmera ◽  
Jindřich Vokoun ◽  
Anna Boeva ◽  
Svatava Dvoráčková ◽  
...  
Keyword(s):  
Unsaturated Acid ◽  
Mass Spectra ◽  
H Nmr ◽  
C Nmr

From S. nemorensis L., var. subdecurrens GRISEB. there were isolated the previously obtained alkaloids nemorensine (I), retroisosenine (II), bulgarsenine (III) and, in addition, the alkaloid oxynemorensine which was assigned the structure VIII on the basis of the interpretation of the 1H-NMR, 13C-NMR, mass spectra, and on that of the identification of the products of hydrolysis and reduction. Furthermore, the isolation of the cis-nemorensic acid (V) as well as that of the unsaturated acid IV, and the transformation of bulgarsenine (III) to nemorensine (I) were described.

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

Synthesis and Structure Assignment of 2-(4-Methoxybenzyl)cyclohexyl β-D-Glucopyranoside Enantiomers

2006 ◽  
Vol 71 (10) ◽  
pp. 1470-1483 ◽  
Author(s):  
David Šaman ◽  
Pavel Kratina ◽  
Jitka Moravcová ◽  
Martina Wimmerová ◽  
Zdeněk Wimmer
Keyword(s):  
Analytical Data ◽  
Chiral Hplc ◽  
Nmr Analysis ◽  
Target Structure ◽  
Enantiomerically Pure ◽  
Whole Cells ◽  
H Nmr ◽  
Structure Assignment ◽  
Related Compounds ◽  
C Nmr

Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.

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