The Experts below are selected from a list of 477 Experts worldwide ranked by ideXlab platform
Hiroshi Tsuchiya - One of the best experts on this subject based on the ideXlab platform.
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bias voltage dependence of molecular orientation of Dialkyl Ketone and fatty acid alkyl ester at the liquid graphite interface
Applied Surface Science, 2014Co-Authors: Masahiro Hibino, Hiroshi TsuchiyaAbstract:Abstract Molecular orientations of self-assembled 18-pentatriacontanone (as Ketone) and stearyl stearate (as ester) monolayers adsorbed on a graphite surface were studied by scanning tunneling microscopy (STM) at the liquid–solid interface. At a positive sample bias, the central areas of the Dialkyl Ketone and fatty acid alkyl ester molecules in the STM images appeared as two bright regions on both sides of a dim spot and a bright region on one side of a dim spot, whereas at a negative sample bias, the areas appeared dim. This contrast variation indicates that a perpendicular carbon skeleton-plane orientation with the CO pointing down on the surface is favorable for a substrate with positive charge and vice versa because of the greater electronegativity of the oxygen atom. Upon the bias voltage reversal, the delay time for the STM image contrast change in the region was observed on a time scale of minutes. The difference between the delay time lengths for the direction of bias polarity change indicates that the perpendicular configuration with CO pointing up is more stable than that with CO pointing down. These results indicate that the use of an electric field along a direction vertical to the monolayer on the substrate provides control over the orientations of the molecules between two stable states at the liquid–solid interface.
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Bias voltage dependence of molecular orientation of Dialkyl Ketone and fatty acid alkyl ester at the liquid–graphite interface
Applied Surface Science, 2014Co-Authors: Masahiro Hibino, Hiroshi TsuchiyaAbstract:Abstract Molecular orientations of self-assembled 18-pentatriacontanone (as Ketone) and stearyl stearate (as ester) monolayers adsorbed on a graphite surface were studied by scanning tunneling microscopy (STM) at the liquid–solid interface. At a positive sample bias, the central areas of the Dialkyl Ketone and fatty acid alkyl ester molecules in the STM images appeared as two bright regions on both sides of a dim spot and a bright region on one side of a dim spot, whereas at a negative sample bias, the areas appeared dim. This contrast variation indicates that a perpendicular carbon skeleton-plane orientation with the CO pointing down on the surface is favorable for a substrate with positive charge and vice versa because of the greater electronegativity of the oxygen atom. Upon the bias voltage reversal, the delay time for the STM image contrast change in the region was observed on a time scale of minutes. The difference between the delay time lengths for the direction of bias polarity change indicates that the perpendicular configuration with CO pointing up is more stable than that with CO pointing down. These results indicate that the use of an electric field along a direction vertical to the monolayer on the substrate provides control over the orientations of the molecules between two stable states at the liquid–solid interface.
Gary A. Molander - One of the best experts on this subject based on the ideXlab platform.
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Synergistic Photoredox/Nickel Coupling of Acyl Chlorides with Secondary Alkyltrifluoroborates: Dialkyl Ketone Synthesis
The Journal of organic chemistry, 2017Co-Authors: Javad Amani, Gary A. MolanderAbstract:Visible light photoredox/nickel dual catalysis has been employed in the cross-coupling of acyl chlorides with potassium alkyltrifluoroborates. This protocol, based on single-electron-mediated alkyl transfer, circumvents the restriction of using reactive alkylmetallic nucleophiles in transition-metal-catalyzed acylation and achieves a mild and efficient method for the synthesis of unsymmetrical alkyl Ketones. In this approach, a variety of acyl chlorides have been successfully coupled with structurally diverse potassium alkyltrifluoroborates, generating the corresponding Ketones with good yields.
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synergistic photoredox nickel coupling of acyl chlorides with secondary alkyltrifluoroborates Dialkyl Ketone synthesis
Journal of Organic Chemistry, 2017Co-Authors: Javad Amani, Gary A. MolanderAbstract:Visible light photoredox/nickel dual catalysis has been employed in the cross-coupling of acyl chlorides with potassium alkyltrifluoroborates. This protocol, based on single-electron-mediated alkyl transfer, circumvents the restriction of using reactive alkylmetallic nucleophiles in transition-metal-catalyzed acylation and achieves a mild and efficient method for the synthesis of unsymmetrical alkyl Ketones. In this approach, a variety of acyl chlorides have been successfully coupled with structurally diverse potassium alkyltrifluoroborates, generating the corresponding Ketones with good yields.
Masahiro Hibino - One of the best experts on this subject based on the ideXlab platform.
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bias voltage dependence of molecular orientation of Dialkyl Ketone and fatty acid alkyl ester at the liquid graphite interface
Applied Surface Science, 2014Co-Authors: Masahiro Hibino, Hiroshi TsuchiyaAbstract:Abstract Molecular orientations of self-assembled 18-pentatriacontanone (as Ketone) and stearyl stearate (as ester) monolayers adsorbed on a graphite surface were studied by scanning tunneling microscopy (STM) at the liquid–solid interface. At a positive sample bias, the central areas of the Dialkyl Ketone and fatty acid alkyl ester molecules in the STM images appeared as two bright regions on both sides of a dim spot and a bright region on one side of a dim spot, whereas at a negative sample bias, the areas appeared dim. This contrast variation indicates that a perpendicular carbon skeleton-plane orientation with the CO pointing down on the surface is favorable for a substrate with positive charge and vice versa because of the greater electronegativity of the oxygen atom. Upon the bias voltage reversal, the delay time for the STM image contrast change in the region was observed on a time scale of minutes. The difference between the delay time lengths for the direction of bias polarity change indicates that the perpendicular configuration with CO pointing up is more stable than that with CO pointing down. These results indicate that the use of an electric field along a direction vertical to the monolayer on the substrate provides control over the orientations of the molecules between two stable states at the liquid–solid interface.
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Bias voltage dependence of molecular orientation of Dialkyl Ketone and fatty acid alkyl ester at the liquid–graphite interface
Applied Surface Science, 2014Co-Authors: Masahiro Hibino, Hiroshi TsuchiyaAbstract:Abstract Molecular orientations of self-assembled 18-pentatriacontanone (as Ketone) and stearyl stearate (as ester) monolayers adsorbed on a graphite surface were studied by scanning tunneling microscopy (STM) at the liquid–solid interface. At a positive sample bias, the central areas of the Dialkyl Ketone and fatty acid alkyl ester molecules in the STM images appeared as two bright regions on both sides of a dim spot and a bright region on one side of a dim spot, whereas at a negative sample bias, the areas appeared dim. This contrast variation indicates that a perpendicular carbon skeleton-plane orientation with the CO pointing down on the surface is favorable for a substrate with positive charge and vice versa because of the greater electronegativity of the oxygen atom. Upon the bias voltage reversal, the delay time for the STM image contrast change in the region was observed on a time scale of minutes. The difference between the delay time lengths for the direction of bias polarity change indicates that the perpendicular configuration with CO pointing up is more stable than that with CO pointing down. These results indicate that the use of an electric field along a direction vertical to the monolayer on the substrate provides control over the orientations of the molecules between two stable states at the liquid–solid interface.
Javad Amani - One of the best experts on this subject based on the ideXlab platform.
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Synergistic Photoredox/Nickel Coupling of Acyl Chlorides with Secondary Alkyltrifluoroborates: Dialkyl Ketone Synthesis
The Journal of organic chemistry, 2017Co-Authors: Javad Amani, Gary A. MolanderAbstract:Visible light photoredox/nickel dual catalysis has been employed in the cross-coupling of acyl chlorides with potassium alkyltrifluoroborates. This protocol, based on single-electron-mediated alkyl transfer, circumvents the restriction of using reactive alkylmetallic nucleophiles in transition-metal-catalyzed acylation and achieves a mild and efficient method for the synthesis of unsymmetrical alkyl Ketones. In this approach, a variety of acyl chlorides have been successfully coupled with structurally diverse potassium alkyltrifluoroborates, generating the corresponding Ketones with good yields.
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synergistic photoredox nickel coupling of acyl chlorides with secondary alkyltrifluoroborates Dialkyl Ketone synthesis
Journal of Organic Chemistry, 2017Co-Authors: Javad Amani, Gary A. MolanderAbstract:Visible light photoredox/nickel dual catalysis has been employed in the cross-coupling of acyl chlorides with potassium alkyltrifluoroborates. This protocol, based on single-electron-mediated alkyl transfer, circumvents the restriction of using reactive alkylmetallic nucleophiles in transition-metal-catalyzed acylation and achieves a mild and efficient method for the synthesis of unsymmetrical alkyl Ketones. In this approach, a variety of acyl chlorides have been successfully coupled with structurally diverse potassium alkyltrifluoroborates, generating the corresponding Ketones with good yields.
Chang-hee Lee - One of the best experts on this subject based on the ideXlab platform.
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Chelation-Assisted C–H and C–C Bond Activation of Allylic Alcohols by a Rh(I) Catalyst under Microwave Irradiation
Synlett, 2017Co-Authors: Chul-ho Jun, Chang-hee LeeAbstract:Chelation-assisted Rh(I)-catalyzed Ketone synthesis from allylic alcohols and alkenes through C–H and C–C bond activations under microwave irradiation was developed. Aldimine is formed via olefin isomerization of allyl alcohol under Rh(I) catalysis and condensation with 2-amino-3-picoline, followed by continuous C–H and C–C bond activations to produce a Dialkyl Ketone. The addition of piperidine accelerates the reaction rate by promoting aldimine formation under microwave conditions.
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Chelation-Assisted C-H and C-C Bond Activation of Allylic Alcohols by a Rh(I) Catalyst under Microwave Irradiation
Synlett, 2017Co-Authors: Chang-hee Lee, Chul-ho JunAbstract:Chelation-assisted Rh(I)-catalyzed Ketone synthesis from allylic alcohols and alkenes through C–H and C–C bond activations under microwave irradiation was developed. Aldimine is formed via olefin isomerization of allyl alcohol under Rh(I) catalysis and condensation with 2-amino-3-picoline, followed by continuous C–H and C–C bond activations to produce a Dialkyl Ketone. The addition of piperidine accelerates the reaction rate by promoting aldimine formation under microwave conditions.