Reaction volumes of excited state photoprocesses

Goodman, Joshua L.; Herman, Michael S.

doi:10.1016/0009-2614(89)85160-7

Cited by 18 publications

(14 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the slopes of E λ φ 1 in Figure and using a value of 1 for the quantum yield of formation of the MLCT complex in every solution, an average contraction of Δ V R,1 = −3.4 ± 0.5 cm 3 /mol was obtained. This volume change is in agreement with the value reported previously for the formation of the MLCT state of Ru(bpy) 3 2+10,23 and attributed to a shortening of the metal−ligand bonds, which corresponds to a small effective radial decrease of about 0.01 Å . The lack of dependence of the volume change for the MLCT formation on the salt composition confirms the assignment of this process to an internal arrangement of the ruthenium complex after light excitation.…”

Section: Resultssupporting

confidence: 92%

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

et al. 1997

View full text Add to dashboard Cite

Laser-induced optoacoustic spectroscopy has been applied to the photoinduced electron-transfer reaction between Ru(bpy)3 2+ and various salts of Fe(III) [Fe(ClO4)3, Fe2(SO4)3, and FeCl3]. The reaction volume changes associated with photoinduced ligand exchange derived from these measurements allowed the determination of partial molar volumes at high dilutions of several species such as FeSO4, FeSO4 +, Fe(SO4)2 -, Fe(OH)2+, FeCl+, FeCl2+, and FeCl2 +, not attainable from other techniques. The volume change of oxidation of Ru(bpy)3 2+ to Ru(bpy)3 3+ at high dilution was also calculated.

show abstract

Section: Resultssupporting

confidence: 92%

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

et al. 1997

View full text Add to dashboard Cite

show abstract

“…This value is ca. 10 times smaller than the experimental Δ V MLCT , indicating already that the contraction upon 3 MLCT formation in water is mainly due to internal rearrangements and that electrostriction effects can be neglected, as it was postulated …”

Section: Discussionmentioning

confidence: 87%

“…This volume reduction of the excited state relative to the ground state has been assigned to a small shortening (ca. 0.01 Å) of the Ru−bpy bonds, after the photoinduced intramolecular electron transfer from the central metal to the bpy ligand . Thus, Ru(bpy) 3 2+ and its 3 MLCT state have essentially the same effective radius.…”

Section: Discussionmentioning

confidence: 95%

Enthalpy, Volume, and Entropy Changes Associated with the Electron Transfer Reaction between the ³MLCT State of Ru(Bpy)₃²⁺ and Methyl Viologen Cation in Aqueous Solutions

Borsarelli

Braslavsky

1999

J. Phys. Chem. A

View full text Add to dashboard Cite

The electron-transfer reaction between the metal-to-ligand charge-transfer triplet (3MLCT) state of Ru(bpy)3 2+ and the methyl viologen cation MV2+ was studied by laser-induced optoacoustic spectroscopy in the 8−35 °C temperature range in aqueous solutions in the absence and in the presence of various 0.1 M sodium salts. The enthalpy and the structural volume changes for the formation of the 3MLCT state, ΔH MLCT = (196 ± 3) kJ/mol and ΔV MLCT = (−3.6 ± 0.2) cm3/mol, were independent of the presence of quencher or salt. The values of ΔH R and ΔV R for the production of the radical ion pair upon quenching of the 3MLCT state by MV2+ strongly depended on the added salt. In neat water the expansion ΔV R = (+10.1 ± 1.2) cm3/mol is due to a decrease in solute−solvent interaction after electron transfer. This value can be calculated with the classical Drude−Nernst equation for electrostriction only if a semiempirical constant is employed instead of the theoretical one. The linear dependence between the relatively large changes in ΔH R and ΔV R along the series of added salts is explained in terms of enthalpy−entropy compensation effects due to the perturbation by the salts of the H-bond network in water. With the reported salt-independent reaction free energy a correlation between the reaction entropy and ΔV R was found, i.e., ΔS R = X/T ΔV R, with X = (14.4 ± 0.8) kJ/cm3, similar to the (c pρ/β) T value at 303 K (near the isokinetic temperature, ca. 300 K) in aqueous solutions (c p = heat capacity; ρ = mass density; β = volume expansion coefficient). The large values of the entropy term are due to the reorganization of the water network around the photoproduced radical ion pair, before recombination.

show abstract

“…The high-spin to low-spin conversion in a d 6 metal ion represents one of the largest intramolecular structural changes one can come across in the transition block: the change from a to configuration results in a ∼15 cm 3 mol –1 volume contraction of the compound37 due primarily (though not exclusively) to a ca. 10% reduction in metal–ligand bond length that accompanies depopulation of the σ* orbitals.…”

Section: Resultsmentioning

confidence: 99%

Insights into the excited state dynamics of Fe(ii) polypyridyl complexes from variable-temperature ultrafast spectroscopy

2019

View full text Add to dashboard Cite

show abstract

Reaction volumes of excited state photoprocesses

Cited by 18 publications

References 31 publications

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

Enthalpy, Volume, and Entropy Changes Associated with the Electron Transfer Reaction between the ³MLCT State of Ru(Bpy)₃²⁺ and Methyl Viologen Cation in Aqueous Solutions

Insights into the excited state dynamics of Fe(ii) polypyridyl complexes from variable-temperature ultrafast spectroscopy

Contact Info

Product

Resources

About

Reaction volumes of excited state photoprocesses

Cited by 18 publications

References 31 publications

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)32+ by Fe(III) in Aqueous Solutions

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)32+ by Fe(III) in Aqueous Solutions

Enthalpy, Volume, and Entropy Changes Associated with the Electron Transfer Reaction between the 3MLCT State of Ru(Bpy)32+ and Methyl Viologen Cation in Aqueous Solutions

Insights into the excited state dynamics of Fe(ii) polypyridyl complexes from variable-temperature ultrafast spectroscopy

Contact Info

Product

Resources

About

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

Structural Volume Changes in Photoinduced Electron Transfer Reactions. Laser-Induced Optoacoustic Studies of Speciation during the Quenching Reaction of Excited Ru(bpy)₃²⁺ by Fe(III) in Aqueous Solutions

Enthalpy, Volume, and Entropy Changes Associated with the Electron Transfer Reaction between the ³MLCT State of Ru(Bpy)₃²⁺ and Methyl Viologen Cation in Aqueous Solutions