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Start Over Author "Smith, Kevin" Journal chemical communications
44 results on '"Smith, Kevin"'

1. 5- and 10-oxocorroles from β-octaalkylcorroles

Author

Di Zazzo, Lorena, primary, Nardis, Sara, additional, Caroleo, Fabrizio, additional, Pizzoli, Francesco, additional, Fronczek, Frank R., additional, Smith, Kevin M., additional, Berna, Beatrice Berionni, additional, and Paolesse, Roberto, additional

Published
2024
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2. New molten metal catalysts for CO2 and CH4 conversion to 2 : 1 H2 : CO syngas.

Author

Cai, Genpei, Zong, Zhiyuan, Smith, Kevin J., and Upham, D. Chester

Subjects
LIQUID metals, METAL catalysts, INDIUM alloys, SYNTHESIS gas, ALLOYS, WATER gas shift reactions, STEAM reforming
Abstract

Activity trends for 22 metals and metal alloys are reported for the conversion of CO2 and CH4 to 2 : 1 H2 : CO syngas and carbon. A correlation is observed between CO2 conversion and the free energy of oxidation by CO2 on pure metal catalysts. Indium and indium alloys activate CO2 at the highest rates. We identify a new bifunctional 20 : 80 mol% Sn–In alloy that activates both CO2 and CH4 while catalyzing both reactions. [ABSTRACT FROM AUTHOR]

Published
2023
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21. Phosphorus complex of corrole

Author

Paolesse, Roberto, primary, Boschi, Tristano, additional, Licoccia, Silvia, additional, Khoury, Richard G., additional, and Smith, Kevin M., additional

Published
1998
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30. Influence of redox non-innocent phenylenediamido ligands on chromium imido hydrogen-atom abstraction reactivity.

Author

Wen Zhou, Smith, Kevin M., and Patrick, Brian O.

Subjects
*OXIDATION-reduction reaction kinetics, *LIGAND exchange reaction kinetics, *ABSTRACTION reactions, *IMIDE synthesis, *AZIDE derivatives
Abstract

Paramagnetic CpCr[(RN)2C6H4] compounds (R = SiMe3,CH2CMe3 and Ph) were treated with R'N3 azides to generate chromium imido complexes, CpCr[(RN) 2C6H4](NR'), with R' = adamantyl, aryl or SO2Ar. The H-atom abstraction reactivity of the imido complexes differed as the R and R' substituents were varied. [ABSTRACT FROM AUTHOR]

Published
2014
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31. Oligomeric porphyrin arrays

Author

Graça H. Vicente, M., Jaquinod, Laurent, and M. Smith, Kevin

Abstract

The field of synthesis and physical characterization of oligomeric porphyrin arrays has been the subject of intense research in recent years. Some of these systems present unique physical and optical properties which reflect the extent of electronic interaction between the monomers in the array, and determines their potential applications in chemistry, physics, and biology. General synthetic approaches to a multitude of porphyrin arrays, including directly linked meso-meso, meso-β, and β-β compounds, oligoporphyrins with fused π-systems, and arrays bearing rigid or flexible spacers, developed by us and by others, are described. X-Ray structures of representative compounds are presented.

Published
1999
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32. Benzoporphyrins viaan olefin ring-closure metathesis methodologyElectronic supplementary information (ESI) available: General procedure and selected characterization data for porphyrins 11–13, 16and 17. See DOI: 10.1039/b607711k

Author

Jiao, Lijuan, Hao, Erhong, Fronczek, Frank R., Vicente, M. Graça H., and Smith, Kevin M.

Abstract

A new route to benzoporphyrins is reported in which readily available vicinal dibromoporphyrins are bis-allylated using the Suzuki reaction, cyclized by way of olefin metathesis and finally oxidized to give mono-, di-, or tri-benzoporphyrins.

Published
2006
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34. Conformational landscape surfing induced by off–on π–π stacking in a porphyrin–quinone dyad

Author

Nurco, Daniel J., Smith, Kevin M., and Fajer, Jack

Abstract

A covalently linked porphyrin–quinone dyad crystallizes with two orientations of the quinone, extended away from (off) and cofacial with the porphyrin macrocycle (on), which induce different conformations of the macrocycle and model the recently proposed structural effect of a nearby residue on the heme prosthetic group of a nitric oxide synthase.

Published
2002

35. β,β'-Fused metallocenoporphyrins

Author

Wang, Hong J. H., Jaquinod, Laurent, Nurco, Daniel J., Vicente, M. Graça H., and Smith, Kevin M.

Abstract

The syntheses of a β,β'-fused ruthenocenoporphyrin (9) and a ferrocenoporphyrin dimer (11) are described.

Published
2001

36. First structural characterization of a covalently bonded porphyrin–carborane system

Author

Vicente, M. Graça H., Nurco, Daniel J., Shetty, Shankar J., Medforth, Craig J., and Smith, Kevin M.

Abstract

The first definitive crystal structure of a covalently bonded carborane–porphyrin system is reported; unusual inter- and intra-molecular carborane–porphyrin interactions are observed in the molecular structure and in variable temperature 1H NMR experiments.

Published
2001

37. Cruciform porphyrin pentamers

Author

Graça H. Vicente, M., T. Cancilla, Mark, B. Lebrilla, Carlito, and M. Smith, Kevin

Abstract

Cruciform porphyrin pentamers 15 and 16 are obtained in good yield by acid-catalyzed tetramerization of ZnII–pyrroloporphyrin 14, followed by oxidation with DDQ; pyrroloporphyrins are in turn obtained from the corresponding pyrrolochlorins by Diels–Alder type reactions of porphyrins involving thermal extrusion of sulfur dioxide from a pyrrole-fused 3-sulfolene.

Published
1998
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38. Synthesis and unusual properties of the first 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraalkylporphyrin

Author

Y. Nelson, Nora, J. Medforth, Craig, J. Nurco, Daniel, M. Smith, Kevin, Jia, Song-Ling, and A. Shelnutt, John

Abstract

The new perhalogenated porphyrin 2,3,7,8,12,13,17,18- octabromo-5,10,15,20-tetrakis(trifluoromethyl)porphinatonickel(II) exhibits several striking features, including an extremely ruffled macrocycle with a very short Ni–N distance, an unusually red-shifted optical spectrum, and, surprisingly, hindered rotation of the meso-trifluoromethyl substituents (ΔG‡278 = 47 kJ mol–1).

Published
1999
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39. Evidence for unusually strong intramolecular hydrogen bonding in highly nonplanar porphyrins

Author

S. Somma, Maria, J. Medforth, Craig, Y. Nelson, Nora, M. Olmstead, Marilyn, G. Khoury, Richard, and M. Smith, Kevin

Abstract

The 1H NMR spectra of the 5,10,15,20-tetraalkylporphyrins 2–4 reveal a large downfield shift of the signal for the NH protons and a reduction in the activation energy for NH tautomerism as the alkyl substituents become larger; these unusual changes can be rationalized in terms of greatly enhanced intramolecular hydrogen bonding of the NH protons as the bulkier substituents distort the macrocycle from planarity and contract the porphyrin core.

Published
1999
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41. Rational approach to the synthesis of meso–meso (5,5′) linked bis-porphyrins

Author

G. Khoury, Richard, Jaquinod, Laurent, and M. Smith, Kevin

Abstract

A novel approach for the synthesis of 5,5′-directly linked metal-free bis-porphyrins is reported; McMurry type coup-ling of dipyrroketones (e.g. 1) leads to 1,1,2,2-tetra(2-pyrrolyl)ethene 2, which after tetra-formylation (to give 3) and MacDonald macrocyclization with a 1,9-di-unsubstituted dihydrodipyrrin 4, affords the 5,5′-bis-porphyrin 5.

Published
1997
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43. Synthesis of polyfunctionalized thiophenes and enediynes via ring-opening reactions of 3-lithiated thieno[2,3-b](and [3,2-b])thiophenes, 3,4-dilithiated thieno[2,3-b]thiophenes and 3,6-dilithiated thieno[3,2-b]thiophenes

Author

S. Fuller, Lance, Iddon MP, Brian, and A. Smith, Kevin

Abstract

Solutions of the title lithiated thienothiophenes were synthesized from 2,5-disubstituted 3,4-dibromothieno[2,3-b]thiophenes or 3,6-dibromothieno[3,2-b]thiophenes via Br → Li exchange with 1.0 or 2.0 equiv. of BuLi (THF, –78 °C), respectively, and gave either polyfunctionalized thiophenes or polyfunctionalized enediynes (by a novel tandem ring-opening process in these cases) on being allowed to warm up to ambient temperature.

Published
1997
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44. Stabilization of neutral oxophlorin π-radicals by bulky meso-alkyl groups

Author

G. Khoury, Richard, Jaquinod, Laurent, M. Shachter, Amy, Y. Nelson, Nora, and M. Smith, Kevin

Abstract

The 15-tert-butyl-5-oxophlorin 1 forms a stable, neutral π-radical species 2, in high yield; the 13,17-bis-unsubstituted 5-oxophlorin analogue 5, under similar conditions, affords the 15-iso-5-oxophlorin 6 and 15-hydroxy compound 7 (both characterized by X-ray crystallography), the latter demonstrating the trapping of the π-radical by dioxygen.

Published
1997
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