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Vincent Humblot - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of a chiral modifier on an oxide surface: Chemical Nature of tartaric acid on rutile TiO2 (110)
Applied Surface Science, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:Abstract Tartaric acid (TA) is one of the most known chiral modifier used in heterogeneous enantioselective catalysis and understanding how it interacts with oxide supports is of significant importance for the design of efficient supported metal catalysts. This work presents a detailed surface science characterisation of (R,R) -TA adsorption on a rutile TiO 2 (110) surface from a Chemical and structural point of view. X-ray Photoelectron Spectroscopy (XPS), High Resolution Electron Energy Loss Spectroscopy (HREELS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) were used to decipher the adsorption mode and geometrical arrangement of TA on TiO 2 (110). For XPS analysis, spectra were compared to references recorded on model metal surfaces, namely Au(111) and Cu(110), on which a better understanding of the TA Chemical Nature is available. On TiO 2 , both XPS and HREELS converged to show the monotartrate Chemical Nature (only one acidic group is deprotonated) of the adsorbed TA molecules, while STM and LEED evidenced a (2 × 1) 2D network arrangement. TA molecules are anchored via both oxygen atoms of one carboxylate group binding directly to two adjacent Ti 5c of the underlying oxide surface. No chiral ordered domains were observed whatever the coverage, suggesting that surface chirality is induced at the molecular level.
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Chemical Nature and thermal decomposition behavior of tartaric acid multilayers on rutile TiO2(110)
Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials Processing Measurement and Phenomena, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:R,R-tartaric acid (RR-TA) thermal stability and decomposition on the rutile TiO2(110) surface was investigated by temperature programmed desorption. The authors show that a majority of RR-TA molecules are desorbed intact from multilayers at around 340 K, while they decompose from the first chemisorbed layer between 460 and 480 K. Complementary information on the Chemical Nature of RR-TA in the multilayer regime was gained by x-ray photoelectron spectroscopy, which shows that biacid molecules form the multilayer while they are monotartrate at the interface.
Elisa Meriggio - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of a chiral modifier on an oxide surface: Chemical Nature of tartaric acid on rutile TiO2 (110)
Applied Surface Science, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:Abstract Tartaric acid (TA) is one of the most known chiral modifier used in heterogeneous enantioselective catalysis and understanding how it interacts with oxide supports is of significant importance for the design of efficient supported metal catalysts. This work presents a detailed surface science characterisation of (R,R) -TA adsorption on a rutile TiO 2 (110) surface from a Chemical and structural point of view. X-ray Photoelectron Spectroscopy (XPS), High Resolution Electron Energy Loss Spectroscopy (HREELS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) were used to decipher the adsorption mode and geometrical arrangement of TA on TiO 2 (110). For XPS analysis, spectra were compared to references recorded on model metal surfaces, namely Au(111) and Cu(110), on which a better understanding of the TA Chemical Nature is available. On TiO 2 , both XPS and HREELS converged to show the monotartrate Chemical Nature (only one acidic group is deprotonated) of the adsorbed TA molecules, while STM and LEED evidenced a (2 × 1) 2D network arrangement. TA molecules are anchored via both oxygen atoms of one carboxylate group binding directly to two adjacent Ti 5c of the underlying oxide surface. No chiral ordered domains were observed whatever the coverage, suggesting that surface chirality is induced at the molecular level.
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Chemical Nature and thermal decomposition behavior of tartaric acid multilayers on rutile TiO2(110)
Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials Processing Measurement and Phenomena, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:R,R-tartaric acid (RR-TA) thermal stability and decomposition on the rutile TiO2(110) surface was investigated by temperature programmed desorption. The authors show that a majority of RR-TA molecules are desorbed intact from multilayers at around 340 K, while they decompose from the first chemisorbed layer between 460 and 480 K. Complementary information on the Chemical Nature of RR-TA in the multilayer regime was gained by x-ray photoelectron spectroscopy, which shows that biacid molecules form the multilayer while they are monotartrate at the interface.
P. Roggero - One of the best experts on this subject based on the ideXlab platform.
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The discovery of the Chemical Nature of tobacco mosaic virus.
Rivista di biologia, 2000Co-Authors: S. Pennazio, P. RoggeroAbstract:: The path to arrive at the elucidation of the Chemical Nature of plant viruses was greatly facilitated by the availability of Tobacco mosaic virus (TMV) as biological tool. The first hypothesis on the Chemical Nature of TMV was advanced in 1899 by the American Albert Wood, who suggested an enzyme Nature. This hypothesis, severely questioned by Harry Hallard in 1915, was re-proposed by several virologists. In 1926, the American Maurice Mulvania concluded that the virus might be a protein with the biological characteristics of an autocatalytic enzyme. Before arriving at the experimental evidence it was necessary to resolve two questions: the estimation of virus infectivity in quantitative terms, performed by Francis Holmes in 1928, and the purification of the virus, performed by Carl George Vinson between 1927 and 1934. Vinson gave a conclusive contribution to solve the question of the Chemical Nature of TMV by settling the protocol of TMV purification. He put forward the hypothesis of the protein Nature in the early 1930s but had not the required firm belief to gave the final experimental evidence of it. Who first arrived at the experimental evidence of the protein Nature of the virus was the American Wendell Meredith Stanley, in 1935. His celebrated work, a classic of the fundamental Virology, was followed by several papers in which this result was firmly reaffirmed. The heuristic value of Stanley's discovery held out a year: the decisive evidence of the actual Chemical Nature of TMV was offered in the late 1936 by an English group under the leadership of Frederick Charles Bawden. In their short paper, Bawden and co-operators demonstrated that TMV had a ribonucleoprotein Nature, a result that was confirmed in the following years for several TMV strains and other viruses. Stanley and his group did accept this result only after a year of reticence and contradictions. The conversion to the ribonucleoprotein Nature raised a dignified protest by Bawden and the sarcasm of his closest co-operator, Norman Wingate Pirie, because Stanley proved to be very reluctant to recognize the merit of the English group. The world of Virology continues to consider Stanley as the first scientist who elucidated the actual Nature of a virus, and this eminent scientist was awarded the Nobel Prize for Chemistry, in 1946. By examining the papers Stanley published from 1937 to 1945, one can however find proof of his ambiguity, a fact that justifies the bitterness of Bawden and the sarcastic comments of Pirie.
Stéphane Chenot - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of a chiral modifier on an oxide surface: Chemical Nature of tartaric acid on rutile TiO2 (110)
Applied Surface Science, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:Abstract Tartaric acid (TA) is one of the most known chiral modifier used in heterogeneous enantioselective catalysis and understanding how it interacts with oxide supports is of significant importance for the design of efficient supported metal catalysts. This work presents a detailed surface science characterisation of (R,R) -TA adsorption on a rutile TiO 2 (110) surface from a Chemical and structural point of view. X-ray Photoelectron Spectroscopy (XPS), High Resolution Electron Energy Loss Spectroscopy (HREELS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) were used to decipher the adsorption mode and geometrical arrangement of TA on TiO 2 (110). For XPS analysis, spectra were compared to references recorded on model metal surfaces, namely Au(111) and Cu(110), on which a better understanding of the TA Chemical Nature is available. On TiO 2 , both XPS and HREELS converged to show the monotartrate Chemical Nature (only one acidic group is deprotonated) of the adsorbed TA molecules, while STM and LEED evidenced a (2 × 1) 2D network arrangement. TA molecules are anchored via both oxygen atoms of one carboxylate group binding directly to two adjacent Ti 5c of the underlying oxide surface. No chiral ordered domains were observed whatever the coverage, suggesting that surface chirality is induced at the molecular level.
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Chemical Nature and thermal decomposition behavior of tartaric acid multilayers on rutile TiO2(110)
Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials Processing Measurement and Phenomena, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:R,R-tartaric acid (RR-TA) thermal stability and decomposition on the rutile TiO2(110) surface was investigated by temperature programmed desorption. The authors show that a majority of RR-TA molecules are desorbed intact from multilayers at around 340 K, while they decompose from the first chemisorbed layer between 460 and 480 K. Complementary information on the Chemical Nature of RR-TA in the multilayer regime was gained by x-ray photoelectron spectroscopy, which shows that biacid molecules form the multilayer while they are monotartrate at the interface.
Rémi Lazzari - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of a chiral modifier on an oxide surface: Chemical Nature of tartaric acid on rutile TiO2 (110)
Applied Surface Science, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:Abstract Tartaric acid (TA) is one of the most known chiral modifier used in heterogeneous enantioselective catalysis and understanding how it interacts with oxide supports is of significant importance for the design of efficient supported metal catalysts. This work presents a detailed surface science characterisation of (R,R) -TA adsorption on a rutile TiO 2 (110) surface from a Chemical and structural point of view. X-ray Photoelectron Spectroscopy (XPS), High Resolution Electron Energy Loss Spectroscopy (HREELS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) were used to decipher the adsorption mode and geometrical arrangement of TA on TiO 2 (110). For XPS analysis, spectra were compared to references recorded on model metal surfaces, namely Au(111) and Cu(110), on which a better understanding of the TA Chemical Nature is available. On TiO 2 , both XPS and HREELS converged to show the monotartrate Chemical Nature (only one acidic group is deprotonated) of the adsorbed TA molecules, while STM and LEED evidenced a (2 × 1) 2D network arrangement. TA molecules are anchored via both oxygen atoms of one carboxylate group binding directly to two adjacent Ti 5c of the underlying oxide surface. No chiral ordered domains were observed whatever the coverage, suggesting that surface chirality is induced at the molecular level.
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Chemical Nature and thermal decomposition behavior of tartaric acid multilayers on rutile TiO2(110)
Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials Processing Measurement and Phenomena, 2019Co-Authors: Elisa Meriggio, Rémi Lazzari, Christophe Méthivier, Pascal David, Stéphane Chenot, Xavier Carrier, Gregory Cabailh, Vincent HumblotAbstract:R,R-tartaric acid (RR-TA) thermal stability and decomposition on the rutile TiO2(110) surface was investigated by temperature programmed desorption. The authors show that a majority of RR-TA molecules are desorbed intact from multilayers at around 340 K, while they decompose from the first chemisorbed layer between 460 and 480 K. Complementary information on the Chemical Nature of RR-TA in the multilayer regime was gained by x-ray photoelectron spectroscopy, which shows that biacid molecules form the multilayer while they are monotartrate at the interface.