Photochemistry of Complex Ions. III. Absolute Quantum Yields for the Photolysis of Some Aqueous Chromium(III) Complexes. Chemical Actinometry in the Long Wavelength Visible Region

Wegner, Ernst E.; Adamson, Arthur W.

doi:10.1021/ja00955a003

Cited by 430 publications

(191 citation statements)

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“…the ferrioxalate actinometer 14, 15 for the UV light, the Reinecke's salt actinometer 16 or Aberchrome 540 17-19 (as a control) for the visible light.…”

Section: Methodsmentioning

confidence: 99%

“…16 Another actinometric compound, which can be used conveniently from 315 up to 600 nm, is Reinecke's complex K[Cr(NH 3 ) 2 (SCN) 4 ], which upon irradiation undergoes a photoaquation reaction with release of a SCN -ion. 16 The quantum yield of the photoreaction shows only a slight dependence on the irradiation wavelength, but the practical procedure is not simple: the SCN -ions are also formed by a fast thermal reaction, so that the solution has to be prepared immediately before the use; also with this precaution the thermal reaction causes troubles in the analytical procedure. 13 Aberchrome 540.…”

Section: Comparison With the Most Common Actinometersmentioning

confidence: 99%

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Photochemical investigation of a photochromic diarylethene compound that can be used as a wide range actinometer

Santos

Ballardini

Belser

et al. 2009

Photochem Photobiol Sci

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The photochromic diarylethene derivative 1,2-bis(5-(4-ethynylphenyl)-2-methylthiophen-3-yl)perfluorocyclopentene (1) was submitted to photochemical, thermal stability and fatigue resistance studies in acetonitrile, also to evaluate its possible application as a new actinometer. This photochromic system covers a wide spectral absorption range, with intense bands in the UV and visible regions for the open-ring and closed-ring isomers, respectively. Very high ring-closure quantum yield values were obtained, in contrast with the low ring-opening quantum yields, which are nevertheless high enough to exploit 1 as an actinometer. The procedure required to determine the photon flux of an irradiation source with this fatigue resistant compound is indeed very simple.

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“…the ferrioxalate actinometer 14, 15 for the UV light, the Reinecke's salt actinometer 16 or Aberchrome 540 17-19 (as a control) for the visible light.…”

Section: Methodsmentioning

confidence: 99%

Section: Comparison With the Most Common Actinometersmentioning

confidence: 99%

Photochemical investigation of a photochromic diarylethene compound that can be used as a wide range actinometer

Santos

Ballardini

Belser

et al. 2009

Photochem Photobiol Sci

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show abstract

“…The total amount of photolysis was limited to less than 5% to avoid light absorption by the photoproduct. Absorbed light intensities were determined by Ferrioxalate [18] and Reineckate [19] actinometry.…”

Section: Methodsmentioning

confidence: 99%

Photochemistry of Biologically Important Transition Metal Complexes. I. Cyanocobalamin and Related Corrin Complexes of Rhodium(III)

Vogler

Hirschmann

Otto

et al. 1976

Ber Bunsenges Phys Chem

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Bei den in dieser Zeitschrift wiedergegebenen Gebrauchsnamen, Handelsnamen, Warenbezeichnungen und dgl handelt es sich häufig um gesetzlich geschützte eingetragene Warenzeichen, auch wenn sie nicht als solche mit ® gekennzeichnet sind. Photochemistry of Biologically Important Transition Metal Complexes. I. Cyanocobalamin and Related Corrin Complexes of Rhodium(III)A. Vogler, R. Hirschmann, H. Otto, and H. KunkelyInstitut für Chemie, Universität Regensburg, 8400 Regensburg, GermanyAbsorptionsspektren, sichtbar und ultraviolett / Emissionsspektren / Komplexverbindungen / PhotochemieThe quantum yield of the well known photoaquation of cyanocobalamin (vitamin B 12 ) was determined ( ~ 10" 4 ) and was found to be independent of the irradiating wavelength. In addition cyanocobalamin did not show the characteristic corrin phosphorescence. In agreement with an earlier suggestion it is concluded that the excitation energy initially absorbed by the corrin ligand is rapidly transferred to a reactive excited LF state which lies below the lowest corrin triplet. This conclusion is supported by the behavior of corrin complexes of Rh(III). Contrary to cyanocobalamin the complex dicyanorhodium(III)-corrin did not undergo a photoaquation but has been shown to emit a strong corrin phosphorescence. These observations are consistent with the assumption that the lowest excited LF state lies now well above the lowest corrin triplet. If both axial cyanide ligands which have a strong field are replaced by the weak-field ligand chloride the energy of the lowest excited LF state should drop considerably. The behavior of dichlororhodium(III)-corrin indicates that the lowest corrin triplet lies only slightly below the lowest excited LF state which is responsible for the photoreactivity. The reactive LF state may be populated from the lowest corrin triplet by thermal activation. At 77 K dichlororhodium(III)-corrin showed a strong corrin phosphorescence. At room temperature this emission was essentially quenched and the complex underwent a photoaquation.Die Quantenausbeute der Photoaquotisierung von Cyanocobalamin (Vitamin B 12 ) wurde bestimmt (<£ ~ 10" 4 ). Die Quantenausbeute war unabhängig von der Wellenlänge des Anregungslichtes. Außerdem zeigte Cyanocobalamin nicht die charakteristische Corrinphosphoreszenz. In Übereinstimmung mit einem früheren Vorschlag wird aus diesen Ergebnissen geschlossen, daß die Anregungsenergie, die zunächst vom Corrinliganden absorbiert wird, rasch auf einen reaktiven angeregten LF-Zustand übertragen wird, der unter dem niedrigsten Corrintriplet liegt. Diese Schlußfolgerung wird durch das Verhalten von Corrinkomplexen von Rh(III) unterstützt. Im Gegensatz zu Cyanocobalamin unterlag Dicyanorhodium(III)-corrin keiner Photoaquotisierung, aber emittiert, wie schon früher gezeigt wurde, eine starke

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“…Quantum yields were determined with a precision of ±10%. Absorbed light intensities were determined by Ferrioxalate [18] and Reineckate [19] actinometry.…”

Section: Methodsmentioning

confidence: 99%

Photochemistry of Biologically Important Transition Metal Complexes. II. Carbonylpiperidinetetraphenylporphine Complexes of Iron(II) and Ruthenium(II)

Vogler

Kunkely

1976

Ber Bunsenges Phys Chem

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Absorptionsspektren, sichtbar und ultraviolett / Emissionsspektren / Komplexverbindungen / PhotochemieCarbonylpiperidinetetraphenylporphineiron(II) and dipiperidinetetraphenylporphineiron(II) do not emit the characteristic porphyrin phosphorescence. It is suggested that the porphyrin singlets initially excited undergo an efficient radiationless transition to an excited state which lies below the lowest porphyrin triplet. It is concluded that this lower excited state initiates the release of coordinated CO which has been observed for a variety of biologically important carbonylporphyrins of iron(II). It is assumed that the reactive state is either an excited CT or, more likely, a LF state. If iron(II) is replaced by the homologous ruthenium(II) the lowest LF excited state lies apparently at higher energies than the lowest porphyrin triplet due to the larger LF splitting of the heavier ruthenium. Hence carbonylpiperidinetetraphenylporphineruthenium(II) dissolved in piperidine shows the typical porphyrin phosphorescence, but undergoes also a simultaneous photosubstitution of CO by piperidine with low efficiency. Quantum yields of CO release and relative emission intensities were determined at two irradiating wavelengths (412 and 530 nm) and at two temperatures (25 °C and 80 °C). The results led to the suggestion that the reactive LF state can be populated from the lower porphyrin triplet by thermal activation. In addition to this thermally activated photolysis a temperature independent contribution seems to be important at higher excitation energies. It is assumed that the deactivation cascade starting from higher excited singlets of the porphyrin ligand includes the population of the reactive LF state before the lowest porphyrin triplet is reached. It is also possible that it is not a LF state but a low-lying CT state which is responsible for the photoreactivity.Carbonylpiperidintetraphenylporphineisen(II) und Dipiperidintetraphenylporphineisen(II) zeigen nicht die charakteristische Porphyrinphosphoreszenz. Es wird angenommen, daß die Porphyrinsinguletts, die zunächst angeregt werden, einer raschen strahlungslosen Desaktivierung zu einem angeregten LF

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Photochemistry of Complex Ions. III. Absolute Quantum Yields for the Photolysis of Some Aqueous Chromium(III) Complexes. Chemical Actinometry in the Long Wavelength Visible Region

Cited by 430 publications

References 0 publications

Photochemical investigation of a photochromic diarylethene compound that can be used as a wide range actinometer

Photochemical investigation of a photochromic diarylethene compound that can be used as a wide range actinometer

Photochemistry of Biologically Important Transition Metal Complexes. I. Cyanocobalamin and Related Corrin Complexes of Rhodium(III)

Photochemistry of Biologically Important Transition Metal Complexes. II. Carbonylpiperidinetetraphenylporphine Complexes of Iron(II) and Ruthenium(II)

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