Synthesis of 3,4-Disubstituted Poly(thiophene)s via Substitution of Poly(3-alkylthiophene)

2001 ◽  
Vol 665 ◽  
Author(s):  
Yuning Li ◽  
George Vamvounis ◽  
Steven Holdcroft
Keyword(s):  
Electrophilic Substitution ◽  
Room Temperature ◽  
Bromine Atom ◽  
Side Chain ◽  
Hydrogen Atoms ◽  
H Nmr ◽  
Regioregular Poly ◽  
Fuming Nitric Acid ◽  
Preliminary Study ◽  
C Nmr

ABSTRACTThe electrophilic substitution of regioregular poly(3-hexylthiophene) (P3HT) at the 4- position was investigated to produce structurally well defined 3,4-disubstituted poly(thiophene)s. When P3HT was treated with N-bromosuccinimide (NBS) in chloroform at 25 to 50 °C, the 4-hydrogen atom in P3HT is completely substituted by bromine, as indicated by the 1H NMR, 13C NMR and elemental analysis. Similarly, the chlorinated product was obtained using N- chlorosuccinimide (NCS) at room temperature. However, only 85% of the 4-hydrogen atoms were replaced by chlorine and ∼15% of the α-hydrogen atoms on the hexyl side chain were chlorinated. P3HT readily reacts with fuming nitric acid in chloroform at 0 °C to generate a nitrated product with almost 100% substitution at the 4-position. Our preliminary study on the futher functionalizaton of these polymers was conducted on the brominated product. Our results showed that the bromine atom in this polymer could be further substituted with other groups.

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.

scholarly journals New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst

2016 ◽  
Vol 11 (2) ◽  
pp. 151 ◽  
Author(s):  
Lahouaria Medjdoub ◽  
Belbachir Mohammed
Keyword(s):  
Nucleophilic Substitution ◽  
Room Temperature ◽  
Montmorillonite Clay ◽  
New Method ◽  
Solid Catalyst ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Crystalline Product ◽  
First Time ◽  
C Nmr

<p>Nucleophilic substitution on hexachlorocyclotriphosphazene (HCCTP) with allylamine in order to give hexa(allylamino)cyclotriphosphazene (HACTP)  is performed for the first time under mild conditions by using diethylether as solvent to replace benzene which is very toxic. The reaction time is reduced to half and also performed at room temperature but especially in the presence of an eco-catalyst called Maghnite-H<sup>+</sup>. This catalyst has a significant role in the industrial scale. In fact, the use of Maghnite is preferred for its many advantages: a very low purchase price compared to other catalysts, the easy removal of the reaction mixture. Then, Maghnite-H<sup>+</sup> is became an excellent catalyst for many chemical reactions. The structure of HACTP synthesized in the presence of Maghnite-H<sup>+</sup> to 5% by weight is confirmed by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, <sup>31</sup>P-NMR (Nuclear magnetic resonance) and FTIR (Fourier Transform Infrared spectroscopy). MALDI-TOF (Matrix-Assisted Laser Desorption/Ionisation-time-of-flight mass spectrometry) is used to establish the molecular weight of HACTP which is 471 g/mol. DSC (Differential Scanning Calorimetery) and TGA (Thermogravimetric Analysis) show that HACTP is a crystalline product with a melting point of 88 °C. It is reactive after melting but is degraded from 230 °C. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 28<sup>th</sup> September 2015; Revised: 5<sup>th</sup> December 2015; Accepted: 4<sup>th</sup> January 2016</em></p><p><strong>How to Cite</strong>: Medjdoub, L., Mohammed, B. (2016). New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 151-160 (doi:10.9767/bcrec.11.2.541.151-160)</p><p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.541.151-160</p>

Metall-π-Komplexe yon Benzolderivaten, XIII Bis(methylthio-η-beiizol)chrom(0) Darstellung und Einsatz als zweizähniger Chelatligand/ Metal-π Complexes of Benzene Derivatives, XIII Bis(methylthio-η-benzene)chromium(0) Preparation and Function as a Bidentate Chelating Ligand

1981 ◽  
Vol 36 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Helmut Burdorf ◽  
Christoph Eischenbroich
Keyword(s):  
Nmr Spectra ◽  
Room Temperature ◽  
Radical Cations ◽  
Esr Spectra ◽  
Benzene Derivatives ◽  
Consecutive Reaction ◽  
H Nmr ◽  
Chelating Ligand ◽  
And Function ◽  
C Nmr

Abstract The thioanisole-π-complexes (methylthio-η-benzene)-(η-benzene)-chromium (2) and bis(methylthio-η-benzene)chromium (3) have been prepared via lithiation of bis(η-benzene)-chromium and consecutive reaction with dimethyldisulfide. 1H NMR and 13C NMR spectra of 2 and 3 as well as ESR-spectra of the corresponding radical cations 2.+ and 3.+ were recorded and analyzed. In contrast to C(η-arene)-Si and C(η-arene)-P bonds, C(y-arene)-S bonds are stable to solvolysis. With (norbornadiene)tetracarbonylmolybdenum, 3 readily forms [bis(methylthio-η-benzene)chromium]tetracarbonylmolybdenum (6) wherein 3 functions as a chelating ligand. 1H and 13C NMR evidence suggests, that at room temperature 6 undergoes rapid conformational interconversions.

Polar effects on 13C NMR chemical shifts and rotational barriers of amides. A dual substituent parameters analysis of N,N-dimethyl-3-(5-substituted-2-furyl)-acrylamides

1987 ◽  
Vol 52 (2) ◽  
pp. 409-424 ◽  
Author(s):  
Zdeněk Friedl ◽  
Stanislav Böhm ◽  
Igor Goljer ◽  
Anna Piklerová ◽  
Daniela Poórová ◽  
...  
Keyword(s):  
Substituent Effect ◽  
Chemical Shifts ◽  
Polar Effect ◽  
Dominant Factor ◽  
Side Chain ◽  
Nmr Chemical Shifts ◽  
Resonance Effects ◽  
H Nmr ◽  
Reverse Substituent Effect ◽  
C Nmr

13C NMR chemical shifts were measured for sixteen N,N-dimethyl-3-(5-substituted-2-furyl)-acrylamides in CDCl3 at 21 °C; the barriers of rotation about the C-N bond ΔGc° were determined by using the 1H NMR coalescence method, and the positions of the IR bands of the ν(C=O) stretching vibrations were measured. The dual substituent parameters (DSP) analysis of the 13C NMR chemical shifts for atoms of the vinylcarboxamide side chain -C(3)H=C(2)H-C(1)=O(-N) gives evidence that the chemical shifts for the C-1 and C-3 atoms are controlled primarily by polar effects (δ(C-3) = -3.12σI - 1.03σR0; λ = ρI/ρR = 3.0), which exert a reverse substituent effect on these atoms. Similarly, the DSP analysis of the ΔGc° and ν(C=O) data shows that the dominant factor of the total substituent effect is the polar effect (λ = 1.95 and 1.70, respectively). A confrontation of the results of the DSP analysis with the CNDO/2 calculated electron densities at the corresponding atoms demonstrates that the reactivity of the entire vinylcarboxamide side chain can be well explained in terms of a combination of the polar effect (π-electron polarization) with resonance effects.

Steroids with the β-crotonate (2-butenoate) side chain

1986 ◽  
Vol 51 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Ivan Černý ◽  
Vladimír Pouzar ◽  
Pavel Drašar ◽  
František Tureček ◽  
Miroslav Havel
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
Lithium Salt ◽  
Side Chain ◽  
H Nmr ◽  
C Nmr

Ethyl (20E)-3β-methoxymethoxy-24-nor-5,20(22)-choladien-23-oate (Va) and analogous derivatives with 5α,5β and Δ5,14 steroid moiety (Vb,Vc and Vd, respectively) were prepared by Wittig-Horner reaction of the corresponding ketones IIa-IId with diethyl ethoxycarbonylmethylphosphonate. In this case the reaction affords exclusively the (E)-isomers, in contrast with the Peterson reaction with lithium salt of ethyl 2-(trimethylsilyl)acetate which gives a mixture of (E)- and (Z)-isomers at the Δ20(22) double bond. The structure of the products was confirmed by 1H NMR and 13C NMR spectroscopy. The crotonates Va-Vd were further converted into the 3-O-succinyl derivatives VIIIa-VIIId.

Influence of Br Modification on Collecting Property of Dodecanoic Acid

2013 ◽  
Vol 826 ◽  
pp. 68-74
Author(s):  
Yi Min Zhu ◽  
Bin Bin Luo ◽  
Jin Yue Mi
Keyword(s):  
Active Sites ◽  
Iron Ore ◽  
Room Temperature ◽  
Bromine Atom ◽  
Dodecanoic Acid ◽  
Mechanism Analysis ◽  
Quartz Surface ◽  
H Nmr ◽  
New Type ◽  
Ft Ir

Bromine atom with strong electronegativity was introduced to a position of dodecanoic acid as a new type collector DZF-3 in iron ore flotation. The structure of DZF-3 synthesized in the paper is verified by FT-IR and 1H-NMR. And the collecting performances of DZF-3 are also presented through a series of flotation experiments of single minerals. Results show that DZF-3 is a kind of efficient collector especially used in room temperature in reverse flotation. Moreover, DZF-3 can collect quartz particles without activated by CaCl2. Mechanism analysis shows that electronegativity and collecting performance of the collecting group-COO- are increased by bromine atom. The enhancement of electronegative of dodecanoic acid by Br substituted in a position results in the competitive adsorption among active sites of Br atom and O atoms of carboxyl group with hydroxyl of quartz surface, then there occurs a chemical reaction between the Sin+(n= 0-4) in quartz surface and active sites in DZF-3 molecules.

Electronic structure of five- and six-coordinate iron(III) tetraazaporphyrin complexes: pyrrole-Cαchemical shift as a useful probe

2008 ◽  
Vol 12 (09) ◽  
pp. 1041-1049 ◽  
Author(s):  
Takahisa Ikeue ◽  
Satoshi Kurahashi ◽  
Makoto Handa ◽  
Tamotu Sugimori ◽  
Mikio Nakamura
Keyword(s):  
Electronic Structure ◽  
Spin State ◽  
Electron Configuration ◽  
Hydrogen Atoms ◽  
Nmr Studies ◽  
Chloride Complexes ◽  
H Nmr ◽  
Intermediate Spin ◽  
Intermediate Spin State ◽  
C Nmr

Electronic structure of a series of five-coordinate Fe ( OArTAzP ) X ( OAr = octaaryltetraazaporphyrin , X = Cl-, Br-, I-; Ar = 4-tert-butylphenyl) have been examined on the basis of1H NMR,13C NMR, and EPR spectroscopy as well as SQUID magnetometry. These complexes adopt the intermediate-spin state as in the case of analogous complexes reported by Fitzgerald et al. (Inorg. Chem. 1992; 31: 2006-2013) and Stuzhin et al. (Inorg. Chim. Acta 1995; 236: 131-139). The13C NMR studies using13C -enriched complexes at the pyrrole α positions have revealed that the pyrrole- Cαsignals appear at extraordinary upfield positions, i.e. -130 to -250 ppm at 273 K, due to the dz2-a2 uand dπ-3 eginteractions. The Curie plots of the pyrrole- Cαsignals have further revealed that the iodide complex adopts a much purer intermediate-spin state than the bromide and chloride complexes. In contrast to the case of Fe ( OArTAzP ) X , six-coordinate [ Fe ( OArTAzP )( CN )2]-showed the pyrrole- Cαsignal at 47 ppm at 273 K, which indicates that the complex adopts the low-spin state with the ( dxy)2( dxz, dyz)3electron configuration. Thus, the13C NMR chemical shift of the pyrrole- Cαsignal turns out to be quite a good probe to elucidate the spin state and electron configuration of iron(III) tetraazaporphyrins, where the1H NMR spectroscopy is less useful because of the absence of the hydrogen atoms as well as the alkyl or aryl groups directly attached to the meso positions.

scholarly journals Synthesis and properties of novel ammonium-based room-temperature gemini ionic liquids

RSC Advances ◽  
2018 ◽  
Vol 8 (46) ◽  
pp. 26255-26265 ◽  
Author(s):  
Xuzhao Yang ◽  
Yun Fang
Keyword(s):  
Ionic Liquids ◽  
Room Temperature ◽  
H Nmr ◽  
C Nmr

Ammonium-based asymmetrical gemini ionic liquids, 1-trimethylammonium-3-(pyridinium)propane bisdicyanamide and 1-trimethylammonium-3-(1-methylpiperidinium)propane bisdicyanamide were respectively synthesized and characterized by 1H NMR and 13C NMR.

Artificial granule suspensions of long side chain poly(3-hydroxyalkanoate)

1995 ◽  
Vol 41 (13) ◽  
pp. 138-142 ◽  
Author(s):  
R. H. Marchessault ◽  
F. G. Morin ◽  
S. Wong ◽  
I. Saracovan
Keyword(s):  
Enzymatic Degradation ◽  
Room Temperature ◽  
Aqueous Suspension ◽  
Side Chain ◽  
Nmr Studies ◽  
Continuous Film ◽  
Enzyme Model ◽  
C Nmr

In vitro preparation of long side chain poly(3-hydroxyalkanoate) artificial granule suspensions that mimic the "as biosynthesized" inclusions in vivo is reported. Elastomeric poly(3-hydroxyalkanoate) can be made into an aqueous suspension of noncrystalline, submicron-sized particles. Light-scattering measurements on these suspensions showed polymer particles in the range of 90–200 nm in diameter. High-resolution 13C-NMR studies demonstrated the noncrystalline character of the in vitro artificial granules. Upon drying at room temperature, the suspensions yielded a continuous film resulting from the coalescence of these polymers with a low glass transition temperature and low Young's modulus. Aqueous suspensions of poly(3-hydroxyoctanoate) are ideal substrates for enzymatic degradation studies because of their stability and purity, since they are self-stabilized. The range of poly(3-hydroxyalkanoates) that can be converted to artificial granules and the methods of preparation are described.Key words: poly(3-hydroxyalkanoate), artificial granules, in vitro bacterial inclusions, enzyme model substrates, poly(3-hydroxyoctanoate).

scholarly journals Experimentelle und semi-empirische Protonen-Hyperfein- kopplungen von 1.3-Benzodioxol-Radikal-Kationen und ihre Korrelation mit Reaktivitäten in elektrophilen Substitutionen

1982 ◽  
Vol 37 (7) ◽  
pp. 680-687 ◽  
Author(s):  
Jörg Fleischhauer ◽  
Sun Ma ◽  
Wolfgang Schleker ◽  
Klaus Gersonde ◽  
Hans Twilfer
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Hyperfine Splitting ◽  
Electrophilic Substitution ◽  
Room Temperature ◽  
Hydrogen Atoms ◽  
Substitution Reactions ◽  
X Band ◽  
Band Spectra ◽  
Good Agreement

Abstract The solution ESR X-band spectra of 1.3-benzodioxole (methylenedioxybenzene) (1), benzo- [1.2-d:4.5-d']bis[1.3]dioxole (2), benzo[1.2-d:3.4-d']bis[1.3]dioxole (3) and benzotris[1.3]dioxole (4) have been measured at room temperature. Hyperfine splitting constants of the aromatic ring protons of the compounds 1 - 3 have been determined. They have been correlated with the HOMO orbital densities of the adjacent carbon atoms and exhibit sufficient correspondence with the reactivities of these compounds in electrophilic substitution reactions. The splitting constants of all protons of the compounds 1 - 4 have been calculated by the INDO and HMO methods and have been compared with the experimental hyperfine values. By perturbation theory applied to the interactions between the π-MO'S of benzene and the dioxole fragment one can explain and understand the magnitudes of the experimental hyperfine splitting constants of the hydrogen atoms of these compounds. In particular, the hyperfine values of the methylene protons calculated by the HMO method are in good agreement with the experimental data.

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