The Experts below are selected from a list of 2169 Experts worldwide ranked by ideXlab platform
Akira Imamura - One of the best experts on this subject based on the ideXlab platform.
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extraction of one handed helical frontier orbital in even n Cumulenes by breaking mirror images of right and left handed helical orbitals theoretical study
Journal of Physical Chemistry C, 2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficien...
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Extraction of One-Handed Helical Frontier Orbital in Even [n]Cumulenes by Breaking Mirror Images of Right- and Left-Handed Helical Orbitals: Theoretical Study
2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficiently large energy splitting in even [n]Cumulene in the framework of C1 molecular symmetry by donor–acceptor substitutions
Thibault Cantat - One of the best experts on this subject based on the ideXlab platform.
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Reactivity and Structural Diversity in the Reaction of Guanidine 1,5,7-Triazabicyclo[4.4.0]dec-5-ene with CO2, CS2, and Other HeteroCumulenes
European Journal of Organic Chemistry, 2017Co-Authors: Niklas Von Wolff, Claude Villiers, Guillaume Lefèvre, Michel Ephritikhine, Pierre Thuéry, Thibault CantatAbstract:The guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) reacted with the heteroCumulenes CO2, CS2, iPr2NCNiPr2, p-tolylNCO, and p-tolylNCS to give three types of products: TBD–CO2 (1) and TBD–p-tolylNCS (5), resulting from the addition of the Cumulene to TBD, TBD(–H)({iPrNH}–C=N{iPr}) (3) and TBD(–H)(p-tolylNHCO) (4), resulting from addition of the N–H bond of TBD to the C=N bond of the Cumulene, and the dithiocarbamate salt [TBDH][TBD(–H)CS2] (2) after transfer of a proton to a second molecule of TBD. Competition reactions indicated that the stability of the compounds decreases in the order 4 > 5 > 1 > 2 > 3. DFT calculations showed that the relative stabilities of the products are governed by both the Lewis acidity of the heteroCumulene and the Bronsted basicity of the TBD(–H)–Cumulene anion, whereas their distinct structures are determined by the latter, with the most basic site governing the geometry of the final product.
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Reactivity and Structural Diversity in the Reaction of Guanidine 1,5,7-Triazabicyclo[4.4.0]dec-5-ene with CO 2 , CS 2 , and Other HeteroCumulenes
European Journal of Organic Chemistry, 2017Co-Authors: Niklas Von Wolff, Claude Villiers, Guillaume Lefèvre, Michel Ephritikhine, Pierre Thuéry, Thibault CantatAbstract:The guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) reacted with the heteroCumulenes CO2, CS2, iPr2NCNiPr2, ptolylNCO and ptolylNCS to give three types of products: TBD-CO2 (1) and TBD-ptolylNCS (5), resulting from addition of the Cumulene to TBD, TBD(-H)({iPrNH}-C=N{iPr}) (3) and TBD(-H)(ptolylNHCO) (4), resulting from addition of the N-H bond of TBD to the C=N bond of the Cumulene, and dithiocarbamate salt [TBDH][TBD(-H)CS2] (2) after transfer of a proton to a second molecule of TBD. Competition reactions indicated that the order of decreasing stability of the compounds is: 4 > 5 > 1 > 2 > 3. DFT calculations showed that the relative stabilities of the products are governed by both the Lewis acidity of the heteroCumulene and the Brønsted basicity of the TBD(-H)-Cumulene anion, while their distinct structures are determined by the latter, with the most basic site governing the geometry of the final product.
Yuuichi Orimoto - One of the best experts on this subject based on the ideXlab platform.
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extraction of one handed helical frontier orbital in even n Cumulenes by breaking mirror images of right and left handed helical orbitals theoretical study
Journal of Physical Chemistry C, 2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficien...
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Extraction of One-Handed Helical Frontier Orbital in Even [n]Cumulenes by Breaking Mirror Images of Right- and Left-Handed Helical Orbitals: Theoretical Study
2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficiently large energy splitting in even [n]Cumulene in the framework of C1 molecular symmetry by donor–acceptor substitutions
Yuriko Aoki - One of the best experts on this subject based on the ideXlab platform.
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extraction of one handed helical frontier orbital in even n Cumulenes by breaking mirror images of right and left handed helical orbitals theoretical study
Journal of Physical Chemistry C, 2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficien...
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Extraction of One-Handed Helical Frontier Orbital in Even [n]Cumulenes by Breaking Mirror Images of Right- and Left-Handed Helical Orbitals: Theoretical Study
2019Co-Authors: Yuuichi Orimoto, Yuriko Aoki, Akira ImamuraAbstract:Even [n]Cumulenes with an even number n of double bonds are known to have degenerate helical frontier orbitals even in linear-chain structures. Theoretical analysis was conducted to separate one-handed helical orbitals from the others in Cumulenes to determine their enantioselective chemical/physical properties. Donor ((NH2)3C−) and acceptor ((NO2)3C−) substituents separate the degenerate energy levels of right- and left-handed helical frontier orbitals in even [n]Cumulenes. Lone pairs (LPs) in the donor group can interact with helical orbitals on the Cumulene backbone, leading to “LP–helical orbital” interactions. A difference in the manner of interaction between left- and right-handed orbitals, depending on the LP direction, breaks the mirror symmetry between them. Consequent energy splitting between left- and right-handed orbitals results in extraction of a one-handed helical frontier orbital only. This is the first example of extracting a one-handed helical frontier orbital while maintaining sufficiently large energy splitting in even [n]Cumulene in the framework of C1 molecular symmetry by donor–acceptor substitutions
Niklas Von Wolff - One of the best experts on this subject based on the ideXlab platform.
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Reactivity and Structural Diversity in the Reaction of Guanidine 1,5,7-Triazabicyclo[4.4.0]dec-5-ene with CO 2 , CS 2 , and Other HeteroCumulenes
European Journal of Organic Chemistry, 2017Co-Authors: Niklas Von Wolff, Claude Villiers, Guillaume Lefèvre, Michel Ephritikhine, Pierre Thuéry, Thibault CantatAbstract:The guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) reacted with the heteroCumulenes CO2, CS2, iPr2NCNiPr2, ptolylNCO and ptolylNCS to give three types of products: TBD-CO2 (1) and TBD-ptolylNCS (5), resulting from addition of the Cumulene to TBD, TBD(-H)({iPrNH}-C=N{iPr}) (3) and TBD(-H)(ptolylNHCO) (4), resulting from addition of the N-H bond of TBD to the C=N bond of the Cumulene, and dithiocarbamate salt [TBDH][TBD(-H)CS2] (2) after transfer of a proton to a second molecule of TBD. Competition reactions indicated that the order of decreasing stability of the compounds is: 4 > 5 > 1 > 2 > 3. DFT calculations showed that the relative stabilities of the products are governed by both the Lewis acidity of the heteroCumulene and the Brønsted basicity of the TBD(-H)-Cumulene anion, while their distinct structures are determined by the latter, with the most basic site governing the geometry of the final product.
