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Wyszukujesz frazę "Hammett correlations" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
NMR Spectral correlations in some Tröger’s bases
Autorzy:
Thirunarayanan, G
Suresh, M.
Powiązania:
https://bibliotekanauki.pl/articles/412650.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
tröger’s bases
NMR spectra
hammett correlations
substituent effects
Opis:
Some Tröger’s bases have been synthesised from substituted anilines and paraformaldehyde in presence of Lewis acid catalyst such as anhydrous AlCl3, through electrophilic substitution reaction. The purities of these Tröger’s bases have been checked by their physical constants and spectroscopic data published earlier in the literature. The NMR chemical shift (δ, ppm) of methylene protons and carbon were assigned. The assigned methylene protons and carbon chemical shifts (δ, ppm) of synthesised Tröger’s bases have been correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituent on methylene protons and carbon were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 1-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectral correlation studies of some substituted (E)-1-Benzylidene-2-(diphenylmethylene) hydrazines
Autorzy:
Arulkumaran, R.
Manikandan, V.
Christuraj, P.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1182844.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
(e)-1-benzylidene-2-(diphenylmethylene) hydrazine
ir and nmr spectra
hammett correlations
Opis:
About ten substituted (E)-1-Benzylidene-2-(diphenylmethylene) hydrazine compounds have been synthesized. They are characterized by their analytical, ultraviolet, infrared and NMR spectral data. From infrared spectra, the CN and N+N vibrational frequencies (cm-1) of the hydrazines have been assigned. From NMR spectra, the chemical shifts (, ppm) of CH proton and C(C6H5)2 carbons of the hydrazines have been assigned. These data are correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the spectral data have been discussed.
Źródło:
World Scientific News; 2017, 62; 93-110
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral LFER in some aryl azine derivatives
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1191375.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Aryl hydrazines
Hammett correlations
IR spectra
NMR spectra
Swain-Lupton’s parameters
Opis:
About ten (Z)-1-(1-(substitutedphenyl)ethylidene)-2-(diphenylmethylene)hydrazines were prepared and their purities were examined by literature method. The infrared and NMR spectra of these hydrazines were recorded. The characteristics C=N and N-N stretches (ν, cm-1) and the chemical shifts (δ, ppm) of methyl protons and carbons were assigned. These spectral have been correlated with Hammett substituent constants, F, R and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses, the effects of substituent on the spectral data have been studied.
Źródło:
World Scientific News; 2016, 33; 79-95
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of substituents on 4-(substituted phenyl sulfonamide)benzoic acids by IR and NMR spectra
Autorzy:
Muthuvel, I.
Thirunarayanan, G.
Dineshkumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/1059444.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
4-(substituted phenyl sulfonamide) benzoic acids
Hammett correlations
IR and NMR spectra
Regression analysis
Opis:
About nine 4-(substituted phenyl sulfonamide) benzoic acid derivatives were synthesized by ultrasound irradiation method. The synthesized sulfonamides were characterized by their physical constants and spectroscopic data. The characteristic infrared SOsym, SOasym, NH and CO vibrations (ν, cm-1), the chemical shifts (δ, ppm) of NH and CO of sulfonamides were assigned and correlated with various Hammett substituent constants and Swain-Lupton parameters using single and multi-regression analysis. From the results of the statistical analysis, the effects of substituents on the spectral frequencies were discussed.
Źródło:
World Scientific News; 2019, 128, 2; 216-233
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectral studies of some N-[(E)-phenylmethylidene]benzenesulfonamides
Autorzy:
Sekar, K. G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412358.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
N-[(E)-phenylmethylidene]benzenesulfonamides
SiO2-H3PO4
Greener synthesis
Hammett correlations
Opis:
A series of some N-[(E)-phenylmethylidene]benzenesulfonamide derivatives have been synthesised using solid SiO2-H3PO4 catalyst under solvent free conditions in microwave irradiation. The synthesised E-N-benzene sulfonilimines purities have been verified by their physical constants and spectroscopic data. The spectral frequencies are correlated with Hammett substituent constants, F and R parameters using linear regression analysis. From the results of statistical analysis the effect of substituents on the group frequencies will be discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 8, 3; 249-258
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectral correlation study of some 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones
Autorzy:
Thirunarayanan, G.
Ravi, K.
Powiązania:
https://bibliotekanauki.pl/articles/412390.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solvent-free cyclization cum acetylation
N-acetyl pyrazoles
IR spectra
NMR spectra
Hammett correlations
Opis:
Some N-acetyl pyrazoles including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones including substituted styryl 3,4-dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: H2SO4 catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75 %. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νC=N and C=O (cm-1) frequencies, NMR chemical shifts (δ, ppm) of Ha, Hb, Hc, CH3 protons, C=N, C=O and CH3 carbons of 1-(3-(3,4-dichlorophenyl)-5-(substitutedphenyl)-4,5-dihydro-1H-pyrazole-1-yl) ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 14; 44-57
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral LFER studies in some N-(substituted phenyl) formamides
Autorzy:
Thirunarayanan, Ganesamoorthy
Muthuvel, Inasekaran
Sathiyendiran, Vasudevan
Powiązania:
https://bibliotekanauki.pl/articles/764126.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
N-(Substituted phenyl)formamides
Sulphated titania(TiO2-SO4–-)
IR and NMR spectra
Anilines
Hammett correlations.
Opis:
A series of N-(substituted phenyl) formamides were synthesised by sulphated titania (TiO2-SO4 2-) catalyzed formylation of substituted anilines and formic acid in acetonitrile medium at room temperature. The synthesised formamide derivatives are characterized by their spectral data. The infrared νNH, CO (cm-1) stretches, chemical shifts(δ, ppm) of NH, COH and ipso carbons(Ar-C-NH) were assigned and correlated with Hammett substituent constants using single and multi-regression analysis. From the results of statistical analyses, the effect of substituents on the spectral data have been studied.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2015, 70, 2
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hammett spectral LFER of some antioxidant substituted benzylidene hydrazines
Autorzy:
Thirunarayanan, G.
Manikandan, V.
Arulkumaran, R.
Rajarajan, M.
Sathiyendiran, V.
Powiązania:
https://bibliotekanauki.pl/articles/1182556.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
(E)-(2
5-dinitrophenyl)-2-(substituted benzylidene)hydrazines
Hammett correlations
IR spectra
NMR spectra
antioxidant activity
hydroxy apatite
Opis:
About nine (E)-(2,5-dinitrophenyl)-2-(substituted benzylidene)hydrazines have been synthesized by hydroxy apatite catalyzed condensation of 2,4-dinitrophenyl hydrazine and substituted benzaldehydes under microwave irradiation conditions. The obtained yields of these hydrazines are more than 85%. The purities of synthesized hydrazines are examined by the analytical and spectroscopic data reported earlier. The infrared spectral C=N, NH frequencies (v, cm-1) and the NMR spectral chemical shifts of CH, NH protons and carbons are assigned and are correlated with Hammett substituent constants, F and R parameter using single and multi-regression analysis. From the results of statistical analysis the effects of substituent on the group frequencies have been discussed. The antioxidant activities of these synthesized hydrazines were measured using DPPH radical scavenging method. The hydroxy- and methoxy- substituted hydrazines shows significant antioxidant activity.
Źródło:
World Scientific News; 2017, 69; 201-219
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solvent-free synthesis and spectral linearity of some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H cyclopenta[b]thiophene-3-carboxamides
Autorzy:
Thirunarayanan, G.
Sekar, K. G.
Powiązania:
https://bibliotekanauki.pl/articles/412418.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solvent-free condensation
SiO2-H3PO4
Imine-carboximido derivatives
IR and NMR spectra
Hammett correlations
Opis:
Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamide derivatives have been synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of 2-amino-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta [b]thiophene-3-carboxamide and various substituted benzaldehydes in microwave irradiation. The yield of the imine-carboximido derivatives has been found to be more than 85 %. The purity of all imine-carboximido derivatives has been checked using their physical constants and spectral data. The spectral data of the imine-carboximido derivatives such as infrared ? (cm-1) of CO, NH, C-N, C-Cl, C-F, C=N, and the NMR chemical shifts (?, ppm) of NH, CH, CO and C=N have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis, the effects of substituent on the above spectral group absorptions have been discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 8, 2; 160-174
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preheated fly-ash catalyzed cyclization ofchalcones: Synthesis of some substituted pyrazole-1-carbothioamides and spectral correlations in 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1 carbothioamides
Autorzy:
Thirunarayanan, G.
Sekar, K. G.
Powiązania:
https://bibliotekanauki.pl/articles/412612.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Pre-heated fly-ash
solvent-free synthesis
Hammett correlations
3-(3, 4-dichlorophenyl)-5-(substituted phenyl)-4
5-dihydro-1H-pyrazole-1-carbothioamides
Opis:
Some substituted 1-thiocarbomyl pyrazolines including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides using solvent-free preheated fly-ash catalyzed cyclization between chalcones and thiosemicarbazide microwave irradiation. The yields of these thiocarbomyl pyrazolines are more than 80 %. The purities of these synthesised pyrazoline derivatives are checked by their physical constants and spectral data earlier reported in the literature The spectral data of these 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides had been correlated, using single and multi-linear regression analysis.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 1; 18-34
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microwave assisted synthesis, spectral studies and antimicrobial activities of some 2′,4′-difluorophenyl chalcones
Autorzy:
Vijayakumar, S.
Arulkumaran, R.
Sundararajan, R.
Sakthinathan, S. P.
Suresh, R.
Kamalakkannan, D.
Ranganathan, K.
Sathiyamoorthy, K.
Mala, V.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412217.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Microwave irradiation
Aldol condensation
Hydroxyapatite
Spectral correlations
Hammett σ constants
antimicrobial activities
Opis:
Some 2′,4′-difluorophenyl chalcones have been synthesized under microwave irradiation using aldol condensation between 2,4-difluoroacetophenone and substituted benzaldehydes using catalytic amount of hydroxyapatite. The yields of the chalcones are more than 85 %. The purities of these synthesized chalcones were examined by their physical constants and spectroscopic data. The UV absorption maxima (λmax, nm), infrared stretches (ν, cm-1) of CO, fingerprint region of CHip/op, CH=CHop, C=Cop modes, NMR chemical shifts (δ, ppm) of vinyl proton, carbon and carbonyl carbons have been assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the statistical analysis the effect of substituent on the above spectral frequencies can be discussed. The antimicrobial activities of these synthesized chalcones have been screened using Bauer-Kirby method.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 1; 68-86
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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