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Alessandro Gallo - One of the best experts on this subject based on the ideXlab platform.
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a strong support effect in selective propane dehydrogenation catalyzed by ga i bu 3 grafted onto γ alumina and silica
ACS Catalysis, 2018Co-Authors: Kai C Szeto, Laurent Delevoye, Zachary R Jones, Nicolas Merle, Cesar Rios, Frederic Le Quemener, Alessandro Gallo, Regis M GauvinAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(≡AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(≡SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmar...
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A Strong Support Effect in Selective Propane Dehydrogenation Catalyzed by Ga(i-Bu)3 Grafted onto γ‑Alumina and Silica
2018Co-Authors: Kai C Szeto, Laurent Delevoye, Regis M Gauvin, Zachary R Jones, Nicolas Merle, Frederic Le Quemener, Alessandro Gallo, César Rios, Susannah L. Scott, Mostafa TaoufikAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmark catalysts and related systems show that the effect of the catalyst diluent is significant under the reaction conditions and must be carefully assessed in order to attribute reactivity correctly
Regis M Gauvin - One of the best experts on this subject based on the ideXlab platform.
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a strong support effect in selective propane dehydrogenation catalyzed by ga i bu 3 grafted onto γ alumina and silica
ACS Catalysis, 2018Co-Authors: Kai C Szeto, Laurent Delevoye, Zachary R Jones, Nicolas Merle, Cesar Rios, Frederic Le Quemener, Alessandro Gallo, Regis M GauvinAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(≡AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(≡SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmar...
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A Strong Support Effect in Selective Propane Dehydrogenation Catalyzed by Ga(i-Bu)3 Grafted onto γ‑Alumina and Silica
2018Co-Authors: Kai C Szeto, Laurent Delevoye, Regis M Gauvin, Zachary R Jones, Nicolas Merle, Frederic Le Quemener, Alessandro Gallo, César Rios, Susannah L. Scott, Mostafa TaoufikAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmark catalysts and related systems show that the effect of the catalyst diluent is significant under the reaction conditions and must be carefully assessed in order to attribute reactivity correctly
Kai C Szeto - One of the best experts on this subject based on the ideXlab platform.
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a strong support effect in selective propane dehydrogenation catalyzed by ga i bu 3 grafted onto γ alumina and silica
ACS Catalysis, 2018Co-Authors: Kai C Szeto, Laurent Delevoye, Zachary R Jones, Nicolas Merle, Cesar Rios, Frederic Le Quemener, Alessandro Gallo, Regis M GauvinAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(≡AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(≡SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmar...
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A Strong Support Effect in Selective Propane Dehydrogenation Catalyzed by Ga(i-Bu)3 Grafted onto γ‑Alumina and Silica
2018Co-Authors: Kai C Szeto, Laurent Delevoye, Regis M Gauvin, Zachary R Jones, Nicolas Merle, Frederic Le Quemener, Alessandro Gallo, César Rios, Susannah L. Scott, Mostafa TaoufikAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmark catalysts and related systems show that the effect of the catalyst diluent is significant under the reaction conditions and must be carefully assessed in order to attribute reactivity correctly
Hoong-kun Fun - One of the best experts on this subject based on the ideXlab platform.
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3-Isobutyl-4-phenylsulfanyl-1H-pyrazol-5-ol
Acta Crystallographica Section E Structure Reports Online, 2011Co-Authors: Tara Shahani, Hoong-kun Fun, R. Venkat Ragavan, V. Vijayakumar, S. SarveswariAbstract:The asymmetric unit of the title compound, C13H16N2OS, contains two independent molecules (A and B). The pyrazole ring [maximum deviations = 0.0049 (17) Å in molecule A and 0.0112 (19) Å in molecule B] makes a dihedral angle of 70.23 (11) and 73.18 (12)° with the phenyl ring in molecules A and B, respectively. The Isobutyl Group in molecule B is disordered over two sets of sites with a ratio of refined occupancies of 0.858 (5):0.142 (5). In the crystal, molecules A and B are linked via a pair of intermolecular N—H...O hydrogen bonds, generating an R22(8) ring motif. These ring motifs are further linked into two-dimensional arrays parallel to the bc plane by intermolecular N—H...O and weak C—H...S hydrogen bonds. The crystal is further stablized by weak π–π interactions [centroid–centroid distances = 3.5698 (13) and 3.5287 (12) Å]
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4-{[(E)-(4-Chlorophenyl)methylidene]amino}-3-{2-[4-(2-methylpropyl)phenyl]ethyl}-1H-1,2,4-triazole-5(4H)-thione
Acta Crystallographica Section E Structure Reports Online, 2009Co-Authors: Hoong-kun Fun, K. V. Sujith, Samuel Robinson Jebas, Balakrishna KallurayaAbstract:The asymmetric unit of the title compound, C21H23ClN4S, contains nine crystallographically independent molecules, labelled A to I. The orientation of the 2-[4-(2-methylpropyl)phenyl]ethyl unit with respect to the rest of the molecule is significantly different in molecules E, F, H and I compared to the other independent molecules. The Isobutyl Group of molecule B is disordered over two orientations, with occupancies of 0.764 (7) and 0.236 (7). The benzene rings of the chlorophenyl and methylpropylphenyl units form dihedral angles of 21.90 (11) and 71.47 (11)°, respectively, with the triazole ring in molecule A [9.15 (11) and 80.37 (11)° in B, 7.14 (11) and 84.06 (11)° in C, 25.76 (11) and 76.59 (11)° in D, 13.68 (11) and 76.82 (10)° in E, 8.38 (11) and 69.77 (10)° in F, 30.34 (11) and 78.12 (11)° in G, 21.20 (11) and 71.58 (10)° in H, and 27.65 (11) and 65.23 (11)° in I]. In each independent molecule, a C—H⋯S hydrogen bond is observed. The crystal packing is stabilized by N—H⋯S and C—H⋯S hydrogen bonds, and by C—H⋯π interactions involving the methylpropylphenyl ring.
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N'-[(E)-4-Chloro-benzyl-idene]-2-(4-Isobutyl-phen-yl)propanohydrazide.
Acta crystallographica. Section E Structure reports online, 2009Co-Authors: Hoong-kun Fun, K. V. Sujith, Chin Sing Yeap, B KallurayaAbstract:The asymmetric unit of title compound, C(20)H(23)ClN(2)O, consists of two crystallographically independent mol-ecules (A and B) in which the orientations of the 4-Isobutyl-phenyl units are different. The Isobutyl Group of mol-ecule B is disordered over two positions with occupancies of 0.850 (5) and 0.150 (5). The dihedral angle between the two benzene rings is 88.70 (9)° in mol-ecule A and 89.38 (9)° in mol-ecule B. The independent mol-ecules are linked together into chains along [100] by N-H⋯O and C-H⋯O hydrogen bonds, and by C-H⋯π inter-actions. In the chain, N-H⋯O and C-H⋯O hydrogen bonds generate R(2) (1)(6) ring motifs. In addition, C-H⋯N hydrogen bonds are observed. The presence of pseudosymmetry in the structure suggests the higher symmetry space Group Pbca but attempts to refine the structure in this space Group resulted in high R (0.119) and wR (0.296) values.
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4-Amino-3-{1-[4-(2-methyl-prop-yl)phen-yl]eth-yl}-1H-1,2,4-triazole-5(4H)-thione.
Acta Crystallographica Section E Structure Reports Online, 2008Co-Authors: Hoong-kun Fun, K. V. Sujith, Parutagouda Shankaragouda Patil, Balakrishna Kalluraya, Suchada ChantraprommaAbstract:In the title triazole compound, C14H20N4S, the dihedral angle between the triazole and benzene rings is 83.29 (11)°. The methine H atom and two methyl Groups of the Isobutyl Group are disordered over two sites with occupancies of 0.684 (9) and 0.316 (9). In the crystal structure, N—H⋯S hydrogen bonds link the molecules into chains running along the b axis. These chains are cross-linked into a two-dimensional network parallel to the ab plane by C—H⋯S hydrogen bonds.
Laurent Delevoye - One of the best experts on this subject based on the ideXlab platform.
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a strong support effect in selective propane dehydrogenation catalyzed by ga i bu 3 grafted onto γ alumina and silica
ACS Catalysis, 2018Co-Authors: Kai C Szeto, Laurent Delevoye, Zachary R Jones, Nicolas Merle, Cesar Rios, Frederic Le Quemener, Alessandro Gallo, Regis M GauvinAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(≡AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(≡SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmar...
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A Strong Support Effect in Selective Propane Dehydrogenation Catalyzed by Ga(i-Bu)3 Grafted onto γ‑Alumina and Silica
2018Co-Authors: Kai C Szeto, Laurent Delevoye, Regis M Gauvin, Zachary R Jones, Nicolas Merle, Frederic Le Quemener, Alessandro Gallo, César Rios, Susannah L. Scott, Mostafa TaoufikAbstract:The reactions of Ga(i-Bu)3 (i-Bu = CH2CH(CH3)2) with the dehydrated and partially dehydroxylated surfaces of alumina (Al2O3–500) and silica (SiO2–700) were studied by IR, high field solid-state NMR and EXAFS spectroscopies, as well as elemental analysis. Grafting onto Al2O3–500 occurs selectively by protonolysis at individual surface hydroxyl Groups, resulting in the formation of mononuclear [(AlO)Ga(i-Bu)2L] (L = surface oxygen) sites as the major surface organometallic entities. Conversely, grafting on silica affords dinuclear species [(SiO)2Ga2(i-Bu)3] by a combination of protonolysis and Isobutyl Group transfer to Si. Further evidence for the difference in nuclearity was obtained by analysis of the WT-EXAFS. The mononuclear alumina-supported Ga sites show much higher activity in propane dehydrogenation than their dinuclear silica-supported counterparts. The propane dehydrogenation reaction may require the presence of Al–O–Ga bonds to promote heterolytic C–H bond activation. Comparisons with benchmark catalysts and related systems show that the effect of the catalyst diluent is significant under the reaction conditions and must be carefully assessed in order to attribute reactivity correctly
