Excited-state behavior of polypyridyl complexes of chromium(III)

Serpone, Nick; Jamieson, Mary A.; Henry, Marian S.; Hoffman, Morton Z.; Bolletta, Fabrizio; Maestri, M.

doi:10.1021/ja00505a019

Cited by 125 publications

(109 citation statements)

References 3 publications

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“…In the presence of triplet dioxygen, the most commonly proposed quenchin pathways for the deactivation of the excited states *Cr(bpy)ji in solution are depicted in Scheme tive quenching) are considered to be endoergonic and have been ruled out (3,4). If the energy transfer quenching pathway (A) is indeed operative, it will lead to the formation of singlet dioxygen.…”

Section: Detection Of Near-infrared Luminescencementioning

confidence: 99%

“…Using all the necessary data and applying eq. [4], a value of @,(CR)= 0.86 ? 0.08 was obtained for reaction [2] in D,O.…”

Section: Time Smentioning

confidence: 99%

“…However, as the value of @,(CR) is less than unity, we suspect that, in addition to energy transfer quenching, another pathway, although minor, may also be operative. The electron transfer quenching mode (pathway B, reductive or oxidative) is considered to be endoergonic (3,4). In addition, very little or opposite variation of quenching rate constant with AOE of the reaction was observed (3).…”

Section: Quenching Mechanismmentioning

confidence: 99%

“…proceeds by an energy transfer pathway leading to singlet dioxygen formation (3,4). However, until now, no direct experimental evidence has been presented in support of the proposed mechanism and, to the best our knowledge, no measurements of the '0, quantum yields have been made.…”

Section: Introductionmentioning

confidence: 96%

“…Such studies have provided useful fundamental information about the nature and reactivity of these excited states (3,4). Furthermore, such studies also provide a simple method of evaluating new luminescent inorganic photosensitizers and their role in mechanistic inorganic photochemistry (5).…”

Section: Introductionmentioning

confidence: 99%

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Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Tiyabhorn¹,

Zahir²

1996

Can. J. Chem.

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Abstract:The formation of singlet dioxygen (lo2) in the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen in deuterium oxide was detected using near-infrared luminescence corresponding to singlet dioxygen decay. In addition, luminescence intensity measurements were used to determine the quantum yield of singlet dioxygen produced. A value of 0.86 ? 0.08 was obtained for the yield of lo2. Based on these quantum yield measurements, it is proposed that the major quenching mode is energy transfer quenching. However, considering that the lo2 yield is less than unity and electron transfer quenching is not a viable pathway, it is proposed that, in addition to the energy transfer quenching, physical quenching involving spin-catalyzed deactivation of Cr(bpy),,+ may also be operative as a minor quenching pathway.Key words: Cr(bpy)33+, singlet dioxygen, quenching, quantum yield.Resume : Utilisant la luminescence infrarouge correspondant j. la dksactivation du dioxygkne singulet, on a dktectk la formation de dioxygkne singulet ('0,) au cours de la rkaction des Ctats doublement excitks du tris(bipyridine)chrome(III) et du dioxygkne triplet dans l'oxyde de deutkrium. De plus, on a utilisk des mesures d'intensitk de la luminescence pour dkterminer le rendement quantique du dioxygkne singulet produit. On a obtenu une valeur de 0,86 0,08 pour le rendement de lo2. Sur la base de ces mesures de rendements quantiques, il est proposk que le mode majeur de dksactivation soit un transfert d'knergie. Toutefois, si l'on considkre que le rendement en lo2 est plus petit que un et que la dksactivation par un transfert d'klectron n'est pas une voie rkactionelle viable, il est suggkrk que, en plus de la dksactivation par transfert d'knergie, la dksactivation physique impliquant une dksactivation du cr(bpy),,+ catalyske par le spin puisse aussi agir comme voie rnineure de dksactivation.

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Section: Detection Of Near-infrared Luminescencementioning

confidence: 99%

“…Using all the necessary data and applying eq. [4], a value of @,(CR)= 0.86 ? 0.08 was obtained for reaction [2] in D,O.…”

Section: Time Smentioning

confidence: 99%

Section: Quenching Mechanismmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Tiyabhorn¹,

Zahir²

1996

Can. J. Chem.

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Electron‐Transfer Processes in Mononuclear Polypyridine Metal Complexes

Vlček

2001

Electron Transfer in Chemistry

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Photooxidizing Chromium Catalysts for Promoting Radical Cation Cycloadditions

2015

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The photooxidizing capabilities of selected Cr III complexes for promoting radical cation cycloadditions are described. These complexes have sufficiently long-lived excited states to oxidize electron-richalkenes,therebyinitiating [4+ +2] processes.T hese metal species augment the spectrum of catalysts explored in photoredox systems,a st hey feature unique properties that can result in differential reactivity from the more commonly employed ruthenium or iridium catalysts.

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Excited-state behavior of polypyridyl complexes of chromium(III)

Cited by 125 publications

References 3 publications

Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Electron‐Transfer Processes in Mononuclear Polypyridine Metal Complexes

Photooxidizing Chromium Catalysts for Promoting Radical Cation Cycloadditions

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