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Francois Diederich - One of the best experts on this subject based on the ideXlab platform.
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New reactivity of 6,6-bis-donor-substituted pentafulvenes: one-step synthesis of highly substituted [3]cumulene and dihydropentalene
Tetrahedron, 2015Co-Authors: Nicolas Kerisit, Aaron D. Finke, Nils Trapp, Yann R. Leroux, Jean-claude Guillemin, Yann Trolez, Francois DiederichAbstract:We report the preparation of a 6,6-bis[(4-N,N-dimethylanilino)ethynyl]pentafulvene from a 6,6-dibromopentafulvene and 4-ethynyl-N,N-Dimethylaniline under Sonogashira cross-coupling conditions. A push–pull [3]cumulene was formed unexpectedly during this reaction in moderate yield. The 6,6-bis[(4-N,N-dimethylanilino)ethynyl]pentafulvene was reacted with tetracyanoethylene, and an unprecedented 1,2-dihydropentalene was obtained in high yield as the exclusive product. The structures of the new compounds are supported by X-ray analysis, and a reasonable mechanism for their formation is proposed. We also report their interesting opto-electronic properties, as studied by UV/vis spectroscopy and cyclic voltammetry (CV).
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expanding the chemical structure space of opto electronic molecular materials unprecedented push pull chromophores by reaction of a donor substituted tetracyanofulvene with electron rich alkynes
Journal of the American Chemical Society, 2013Co-Authors: Govindasamy Jayamurugan, Jeanpaul Gisselbrecht, Corinne Boudon, Bernd W Schweizer, Bruno Bernet, Oliver Dumele, Francois DiederichAbstract:The reaction of a 3,5-bis(N,N-dimethylanilino)-substituted 2,4,6,6-tetracyanopentafulvene (TCPF) with mono- and bis(N,N-dimethylanilino)acetylene provides facile access to push–pull chromophores with diverse new scaffolds. The starting TCPF reacts with bis(N,N-dimethylanilino)acetylene in a formal [2+2] cycloaddition at the exocyclic double bond, followed by retroelectrocyclization, to yield an ethenylene-extended push–pull pentafulvene. The transformation with 4-ethynyl-N,N-Dimethylaniline also yields a similar extended pentafulvene as well as two other products that required X-ray analysis for their structure elucidation. One features an 8,8-dicyanoheptafulvene core formed by formal [2+2] cycloaddition, followed by ring opening via fragmentation. The second is a chiral cyclobutenylated tetrahydropentalene, resulting from a cascade of formal [6+2] and [2+2] cycloadditions. All new nonplanar push–pull chromophores display amphoteric redox behavior with both strong electron-donating and -accepting potency....
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expanding the chemical space for push pull chromophores by non concerted 2 2 and 4 2 cycloadditions access to a highly functionalised 6 6 dicyanopentafulvene with an intense low energy charge transfer band
Chemical Communications, 2011Co-Authors: Govindasamy Jayamurugan, Jeanpaul Gisselbrecht, Corinne Boudon, Franziska Schoenebeck, Bernd W Schweizer, Bruno Bernet, Francois DiederichAbstract:Non-concerted [2+2] and [4+2] cycloadditions between N,N-dimethylanilino-substituted 1,1,2,4,4-pentacyanobuta-1,3-diene and 4-ethynyl-N,N-Dimethylaniline are controlled by solvent polarity and provide access to a highly functionalised 6,6-dicyanopentafulvene featuring an intense, low-energy charge-transfer band and to an unusual spirocyclic zwitterion, characterised by X-ray analysis.
Chavalit Ratanatamskul - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of 2,6-Dimethylaniline oxidation by various Fenton processes.
Journal of hazardous materials, 2011Co-Authors: Nalinrut Masomboon, Chavalit RatanatamskulAbstract:Abstract The kinetics of 2,6-Dimethylaniline degradation by Fenton process, electro-Fenton process and photoelectro-Fenton process was investigated. This study attempted to eliminate the potential interferences from intermediates by making a kinetics comparison of Fenton, electro-Fenton and photoelectro-Fenton methods through use initial rate techniques during the first 10 min of the reaction. Exactly how the initial concentration of 2,6-Dimethylaniline, ferrous ions and hydrogen peroxide affects 2,6-Dimethylaniline degradation was also examined. Experimental results indicate that the 2,6-Dimethylaniline degradation in the photoelectro-Fenton process is superior to the ordinary Fenton and electro-Fenton processes. Additionally, for 100% removal of 1 mM 2,6-Dimethylaniline, the supplementation of 1 mM of ferrous ion, 20 mM of hydrogen peroxide, current density at 15.89 A m −2 and 12 UVA lamps at pH 2 was necessary. The overall rate equations for 2,6-Dimethylaniline degradation by Fenton, electro-Fenton and photoelectro-Fenton processes were proposed as well.
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Effect of carrier composition on 2,6-Dimethylaniline degradation in aqueous solution by fluidized-bed Fenton process.
Environmental technology, 2011Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:The fluidized-bed Fenton process is an alternative process that decreases iron sludge from the Fenton reaction by using carriers to crystallize iron on to the surface of the carrier. In this study, the target compound is 2,6-Dimethylaniline, which is a carcinogen and difficult to degrade. This study examined the effect of different carriers on the degradation of 2,6-Dimethylaniline by a fluidized-bed Fenton process. The six carriers were alumina dioxide (Al2O3), silica dioxide (SiO2), and black, white, brown and coloured gravels. The results revealed that differences in the composition of elements and the structures of each carrier have different effects on the oxidation of 2,6-Dimethylaniline. The carriers containing Ca were not suitable for use in the fluidized-bed Fenton process. In contrast, Al2O3 and SiO2 were more efficient at removing 2,6-Dimethylaniline, and the pH value was almost stable. Moreover, 2,6-dimethylanililne removal efficiency of Al2O3 was higher compared with the other carriers. Therefore, in this study, Al2O3 was an optimum carrier for the oxidation of 2,6-Dimethylaniline.
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Effect of carrier composition on 2,6-Dimethylaniline degradation in aqueous solution by fluidized-bed Fenton process.
Environmental Technology, 2011Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:The fluidized‐bed Fenton process is an alternative process that decreases iron sludge from the Fenton reaction by using carriers to crystallize iron on to the surface of the carrier. In this study, the target compound is 2,6‐Dimethylaniline, which is a carcinogen and difficult to degrade. This study examined the effect of different carriers on the degradation of 2,6‐Dimethylaniline by a fluidized‐bed Fenton process. The six carriers were alumina dioxide (Al2O3), silica dioxide (SiO2), and black, white, brown and coloured gravels. The results revealed that differences in the composition of elements and the structures of each carrier have different effects on the oxidation of 2,6‐Dimethylaniline. The carriers containing Ca were not suitable for use in the fluidized‐bed Fenton process. In contrast, Al2O3 and SiO2 were more efficient at removing 2,6‐Dimethylaniline, and the pH value was almost stable. Moreover, 2,6‐dimethylanililne removal efficiency of Al2O3 was higher compared with the other carriers. There...
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Oxidation of 2,6-Dimethylaniline by the fluidized-bed Fenton process
Reaction Kinetics Mechanisms and Catalysis, 2010Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:2,6-Dimethylaniline was oxidized using the fluidized-bed Fenton process. This study examined the effects of pH, ferrous ion, hydrogen peroxide and 2,6-Dimethylaniline concentrations. Results showed that the optimum pH for removing 2,6-Dimethylaniline was 3. Ferrous ion and hydrogen peroxide concentrations were the important parameters in 2,6-Dimethylaniline degradation. Increasing ferrous ion and hydrogen peroxide concentrations can enhance the degradation efficiency of 2,6-Dimethylaniline. However, excess amounts of ferrous ions and hydrogen peroxide can cause scavenging effects in the reaction, thus decreasing the 2,6-Dimethylaniline removal efficiency. The optimum concentrations of ferrous ion and hydrogen peroxide for degrading 1 mM of 2,6-Dimethylaniline were 2.5 mM and 10 mM, respectively. In addition, the fluidized-bed Fenton process was proven to have higher degradation ability than the conventional Fenton process.
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Mineralization of 2,6-Dimethylaniline by photoelectro-Fenton process
Applied Catalysis A-general, 2010Co-Authors: Nalinrut Masomboon, Chavalit RatanatamskulAbstract:A new approach to promoting ferric reduction efficiency using electrochemical, photoreduction and photo-assisted electrochemical processes has been developed. The use of UVA irradiation and electric current as electron donors can efficiently initiate a Fenton reaction called the photoelectro-Fenton process. 2,6-Dimethylaniline was the target compound in this study. Parameters including initial pH, ferrous ion dosage, hydrogen peroxide concentration, the electric current applied and the number of UVA lamps used were investigated to evaluate the performance of the photoelectro-Fenton process. The removal efficiencies of 2,6-Dimethylaniline, COD, TOC and initial degradation rate were determined in this study. The optimum condition for 1 mM of 2,6-Dimethylaniline degradation was achieved when using 1 mM of ferrous ions, 20 mM of hydrogen peroxide at pH 2 and 2 A of electric current applied with four UVA lamps used. The energy cost, reaction mechanism and intermediates identification of 2,6-Dimethylaniline degradation have also been determined in this study.
Nalinrut Masomboon - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of 2,6-Dimethylaniline oxidation by various Fenton processes.
Journal of hazardous materials, 2011Co-Authors: Nalinrut Masomboon, Chavalit RatanatamskulAbstract:Abstract The kinetics of 2,6-Dimethylaniline degradation by Fenton process, electro-Fenton process and photoelectro-Fenton process was investigated. This study attempted to eliminate the potential interferences from intermediates by making a kinetics comparison of Fenton, electro-Fenton and photoelectro-Fenton methods through use initial rate techniques during the first 10 min of the reaction. Exactly how the initial concentration of 2,6-Dimethylaniline, ferrous ions and hydrogen peroxide affects 2,6-Dimethylaniline degradation was also examined. Experimental results indicate that the 2,6-Dimethylaniline degradation in the photoelectro-Fenton process is superior to the ordinary Fenton and electro-Fenton processes. Additionally, for 100% removal of 1 mM 2,6-Dimethylaniline, the supplementation of 1 mM of ferrous ion, 20 mM of hydrogen peroxide, current density at 15.89 A m −2 and 12 UVA lamps at pH 2 was necessary. The overall rate equations for 2,6-Dimethylaniline degradation by Fenton, electro-Fenton and photoelectro-Fenton processes were proposed as well.
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Effect of carrier composition on 2,6-Dimethylaniline degradation in aqueous solution by fluidized-bed Fenton process.
Environmental technology, 2011Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:The fluidized-bed Fenton process is an alternative process that decreases iron sludge from the Fenton reaction by using carriers to crystallize iron on to the surface of the carrier. In this study, the target compound is 2,6-Dimethylaniline, which is a carcinogen and difficult to degrade. This study examined the effect of different carriers on the degradation of 2,6-Dimethylaniline by a fluidized-bed Fenton process. The six carriers were alumina dioxide (Al2O3), silica dioxide (SiO2), and black, white, brown and coloured gravels. The results revealed that differences in the composition of elements and the structures of each carrier have different effects on the oxidation of 2,6-Dimethylaniline. The carriers containing Ca were not suitable for use in the fluidized-bed Fenton process. In contrast, Al2O3 and SiO2 were more efficient at removing 2,6-Dimethylaniline, and the pH value was almost stable. Moreover, 2,6-dimethylanililne removal efficiency of Al2O3 was higher compared with the other carriers. Therefore, in this study, Al2O3 was an optimum carrier for the oxidation of 2,6-Dimethylaniline.
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Effect of carrier composition on 2,6-Dimethylaniline degradation in aqueous solution by fluidized-bed Fenton process.
Environmental Technology, 2011Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:The fluidized‐bed Fenton process is an alternative process that decreases iron sludge from the Fenton reaction by using carriers to crystallize iron on to the surface of the carrier. In this study, the target compound is 2,6‐Dimethylaniline, which is a carcinogen and difficult to degrade. This study examined the effect of different carriers on the degradation of 2,6‐Dimethylaniline by a fluidized‐bed Fenton process. The six carriers were alumina dioxide (Al2O3), silica dioxide (SiO2), and black, white, brown and coloured gravels. The results revealed that differences in the composition of elements and the structures of each carrier have different effects on the oxidation of 2,6‐Dimethylaniline. The carriers containing Ca were not suitable for use in the fluidized‐bed Fenton process. In contrast, Al2O3 and SiO2 were more efficient at removing 2,6‐Dimethylaniline, and the pH value was almost stable. Moreover, 2,6‐dimethylanililne removal efficiency of Al2O3 was higher compared with the other carriers. There...
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Oxidation of 2,6-Dimethylaniline by the fluidized-bed Fenton process
Reaction Kinetics Mechanisms and Catalysis, 2010Co-Authors: Chavalit Ratanatamskul, Sutthinee Narkwittaya, Nalinrut MasomboonAbstract:2,6-Dimethylaniline was oxidized using the fluidized-bed Fenton process. This study examined the effects of pH, ferrous ion, hydrogen peroxide and 2,6-Dimethylaniline concentrations. Results showed that the optimum pH for removing 2,6-Dimethylaniline was 3. Ferrous ion and hydrogen peroxide concentrations were the important parameters in 2,6-Dimethylaniline degradation. Increasing ferrous ion and hydrogen peroxide concentrations can enhance the degradation efficiency of 2,6-Dimethylaniline. However, excess amounts of ferrous ions and hydrogen peroxide can cause scavenging effects in the reaction, thus decreasing the 2,6-Dimethylaniline removal efficiency. The optimum concentrations of ferrous ion and hydrogen peroxide for degrading 1 mM of 2,6-Dimethylaniline were 2.5 mM and 10 mM, respectively. In addition, the fluidized-bed Fenton process was proven to have higher degradation ability than the conventional Fenton process.
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Mineralization of 2,6-Dimethylaniline by photoelectro-Fenton process
Applied Catalysis A-general, 2010Co-Authors: Nalinrut Masomboon, Chavalit RatanatamskulAbstract:A new approach to promoting ferric reduction efficiency using electrochemical, photoreduction and photo-assisted electrochemical processes has been developed. The use of UVA irradiation and electric current as electron donors can efficiently initiate a Fenton reaction called the photoelectro-Fenton process. 2,6-Dimethylaniline was the target compound in this study. Parameters including initial pH, ferrous ion dosage, hydrogen peroxide concentration, the electric current applied and the number of UVA lamps used were investigated to evaluate the performance of the photoelectro-Fenton process. The removal efficiencies of 2,6-Dimethylaniline, COD, TOC and initial degradation rate were determined in this study. The optimum condition for 1 mM of 2,6-Dimethylaniline degradation was achieved when using 1 mM of ferrous ions, 20 mM of hydrogen peroxide at pH 2 and 2 A of electric current applied with four UVA lamps used. The energy cost, reaction mechanism and intermediates identification of 2,6-Dimethylaniline degradation have also been determined in this study.
Govindasamy Jayamurugan - One of the best experts on this subject based on the ideXlab platform.
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expanding the chemical structure space of opto electronic molecular materials unprecedented push pull chromophores by reaction of a donor substituted tetracyanofulvene with electron rich alkynes
Journal of the American Chemical Society, 2013Co-Authors: Govindasamy Jayamurugan, Jeanpaul Gisselbrecht, Corinne Boudon, Bernd W Schweizer, Bruno Bernet, Oliver Dumele, Francois DiederichAbstract:The reaction of a 3,5-bis(N,N-dimethylanilino)-substituted 2,4,6,6-tetracyanopentafulvene (TCPF) with mono- and bis(N,N-dimethylanilino)acetylene provides facile access to push–pull chromophores with diverse new scaffolds. The starting TCPF reacts with bis(N,N-dimethylanilino)acetylene in a formal [2+2] cycloaddition at the exocyclic double bond, followed by retroelectrocyclization, to yield an ethenylene-extended push–pull pentafulvene. The transformation with 4-ethynyl-N,N-Dimethylaniline also yields a similar extended pentafulvene as well as two other products that required X-ray analysis for their structure elucidation. One features an 8,8-dicyanoheptafulvene core formed by formal [2+2] cycloaddition, followed by ring opening via fragmentation. The second is a chiral cyclobutenylated tetrahydropentalene, resulting from a cascade of formal [6+2] and [2+2] cycloadditions. All new nonplanar push–pull chromophores display amphoteric redox behavior with both strong electron-donating and -accepting potency....
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expanding the chemical space for push pull chromophores by non concerted 2 2 and 4 2 cycloadditions access to a highly functionalised 6 6 dicyanopentafulvene with an intense low energy charge transfer band
Chemical Communications, 2011Co-Authors: Govindasamy Jayamurugan, Jeanpaul Gisselbrecht, Corinne Boudon, Franziska Schoenebeck, Bernd W Schweizer, Bruno Bernet, Francois DiederichAbstract:Non-concerted [2+2] and [4+2] cycloadditions between N,N-dimethylanilino-substituted 1,1,2,4,4-pentacyanobuta-1,3-diene and 4-ethynyl-N,N-Dimethylaniline are controlled by solvent polarity and provide access to a highly functionalised 6,6-dicyanopentafulvene featuring an intense, low-energy charge-transfer band and to an unusual spirocyclic zwitterion, characterised by X-ray analysis.
P.p. Patil - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of corrosion inhibitive poly(2,5-Dimethylaniline) coatings on low carbon steel
Journal of Materials Science, 2006Co-Authors: Vandana Shinde, Sudhakar R. Sainkar, S. A. Gangal, P.p. PatilAbstract:An attempt has been made towards the synthesis of strongly adherent poly(2,5-Dimethylaniline) coatings on low carbon steel substrates, with an objective of examining the possibility of using this polymer for corrosion protection of steel in chloride environment. In this work, the poly(2,5-Dimethylaniline) coatings were synthesized by electrochemical polymerization of 2,5-Dimethylaniline using sodium salicylate as a supporting electrolyte. The characterization of these coatings was carried out by cyclic voltammetry, UV-visible absorption spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The results of these characterizations indicate that the aqueous salicylate solution is a suitable medium for the electrochemical polymerization of 2,5-Dimethylaniline to generate strongly adherent and smooth poly(2,5-Dimethylaniline) coatings on low carbon steel substrates. The performance of poly(2,5-Dimethylaniline) as protective coating against corrosion of low carbon steel in aqueous 3% NaCl was assessed by the open circuit potential and the potentiodynamic polarization measurements. The potentiodynamic polarization measurement reveals that the poly(2,5-Dimethylaniline) coating increases the corrosion potential and reduces the corrosion rate of low carbon steel almost by a factor of 50. This study clearly ascertains that the poly(2,5-Dimethylaniline) has outstanding capability to protect low carbon steel against corrosion in chloride environment.
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Synthesis and characterization of corrosion protective poly(2,5-Dimethylaniline) coatings on copper
Applied Surface Science, 2006Co-Authors: Vandana Shinde, A.b. Gaikwad, P.p. PatilAbstract:Abstract Poly(2,5-Dimethylaniline) coatings were synthesized on copper (Cu) by electrochemical polymerization of 2,5-Dimethylaniline in aqueous salicylate solution by using cyclic voltammetry. The characterization of these coatings was carried out by cyclic voltammetry, UV–visible absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The results of these characterizations indicate that the aqueous salicylate solution is a suitable medium for the electrochemical polymerization of 2,5-Dimethylaniline to generate strongly adherent and smooth poly(2,5-Dimethylaniline) coatings on Cu substrates. The performance of poly(2,5-Dimethylaniline) as protective coating against corrosion of Cu in aqueous 3% NaCl was assessed by the potentiodynamic polarization technique. The results of the potentiodynamic polarization demonstrate that the poly(2,5-Dimethylaniline) coating has ability to protect the Cu against corrosion. The corrosion potential was about 0.078 V versus SCE more positive in aqueous 3% NaCl for the poly(2,5-Dimethylaniline) coated Cu than that of uncoated Cu and reduces the corrosion rate of Cu almost by a factor of 31.