Singlet excited-state absorption of eosin Y

Penzkofer, Alfons; Beidoun, A.; Speiser, Shammai

doi:10.1016/0301-0104(93)80099-u

Cited by 39 publications

(25 citation statements)

References 47 publications

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“…The dashdotted curve shows the shifted triplet-triplet absorption spectrum a T {v-v Sx ) for comparing with the S 0 -S" (S" higher lying singlet states) absorption spectrum (dashed curve) (triplet-triplet absorption starts from p Tl ; singlet-singlet excited-state absorption starts from v Sl ). The triplet-triplet absorption crosssection spectrum is of the same order of magnitude as the Si-S" excited-state absorption cross-section spectrum [60]. Previously reported triplet-triplet absorption cross sections of eosin Y are listed in table 2.…”

Section: Data Analysis and Discussionmentioning

confidence: 67%

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Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Penzkofer

Beidoun

1993

Chemical Physics

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The absolute triplet-triplet absorption cross-section spectrum a T (X) of eosin Y in methanol at room temperature is determined in the wavelength region from 400 to 1000 nm and at 308 and 1054 nm. The triplet state is populated by XeCl excimer laser excitation to a singlet state and subsequent intersystem crossing. The triplet level population is determined by numerical simulation of the pump pulse absorption dynamics. The triplet-triplet absorption is probed with picosecond spectral light continua which are generated in a D 2 0 sample by a synchronized mode-locked Nd:glass laser. The decay of the triplet level population is studied by delayed picosecond light continua probing. Second order rate constants of hQ* =* i.l X10 9 dm 3 mol~l s~l for oxygen quenching, fc&> = i.3x 10 9 dm 3 mol~l s~l for triplet-triplet annihilation, and k$ ss4x 10 8 dm 3 mol~l s" 1 for triplet-singlet concentration quenching have been determined.

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Section: Data Analysis and Discussionmentioning

confidence: 67%

“…The energy level positions of the S, state (v Sl , from ref. [60]) and of the T { state (# Tl , from refs. [73,75,76]) are indicated by vertical bars.…”

Section: Data Analysis and Discussionmentioning

confidence: 99%

Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Penzkofer

Beidoun

1993

Chemical Physics

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“…57 The decay of the transient signals at the maximum of the band can be fitted to a biexponential decay with times of ca. 0.2 and 7 ps, very similar for free eosin and eosin at the surface.…”

Section: Resultsmentioning

confidence: 99%

Aqueous Solvation Dynamics at Metal Oxide Surfaces

et al. 2006

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Broadband transient absorption (TA) spectroscopy, three-pulse photon echo peak shift (3PEPS), and anisotropy decay measurements were used to study the solvation dynamics in bulk water and interfacial water at ZrO 2 surfaces, using Eosin Y as a probe. The 3PEPS results show a multiexponential behavior with two subpicosecond components that are similar in bulk and interfacial water, while a third component of several picoseconds is significantly lengthened at the interface. The bandwidth correlation function from TA spectra exhibits the same behavior, and the TA spectra are well reproduced using the doorway-window picture with the time constants from PEPS. Our results suggest that interfacial water is restricted to a thickness of less than 5 Å. Also the high-frequency collective dynamics of water does not seem to be affected by the interface. On the other hand, the increase of the third component may point to a slowing down of diffusional motion at the interface, although other effects, may play a role, which are discussed.

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“…At 387 nm, the singlet excited state of eosin and its semireduced form EO -• have similar absorption cross sections. 49,50 The appearance of EO -• could result from a singlet-singlet reaction and will be discussed below. The decay of the transient absorption in the near UV follows biphasic kinetics in the picosecond time frame with 12 and 140 ps time constants.…”

Section: Resultsmentioning

confidence: 99%

Femtosecond Dynamics of Interfacial and Intermolecular Electron Transfer at Eosin-Sensitized Metal Oxide Nanoparticles

2003

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Photoinduced electron injection from eosin Y into the conduction band of titanium dioxide was further scrutinized, as previous studies on the charge injection from xanthene dyes have led to diverging conclusions. Eosin-sensitized TiO 2 constitutes in many aspects a model system for studying the dynamics of charge injection: Adsorption of the sensitizer onto the oxide surface through electrostatic interaction and hydrogen bonding make this system exemplary of the weak electronic coupling case. The formation of dimeric eosin on the surface of metal oxide nanoparticles in an aqueous suspension was inferred from the study of the deactivation of the dye's singlet excited state on insulating particles, such as ZrO 2 and Al 2 O 3 , and of the formation of the resulting radical ion pair, using femtosecond stimulated emission and transient absorption. It was found that dimers undergo ultrafast dismutation with a time constant of 500 fs. The same process occurs also on TiO 2 particles and results in a competition between interfacial and intermolecular electron transfer. Two time constants of 160 fs (58%) and 1 ps were obtained for the charge injection from the singlet excited state of eosin into this semiconductor. The presence of poly(vinyl alcohol), often used as a stabilizer for aqueous colloidal suspensions, was observed to prevent the dimer formation on the surface but also to slow the rate of electron injection by orders of magnitude. This observation is rationalized in terms of an increased distance between the semiconductor surface and the chromophore because of the adsorption of polymeric chains onto the particles and a decrease of the electronic coupling matrix element associated to the charge transfer process. These findings remove the apparent discrepancies perceived between early measurements and more recent reports and highlight the role played by the mode of adsorption of the sensitizer in controlling electron injection kinetics.

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Singlet excited-state absorption of eosin Y

Abstract: The absolute S,-state excited-state absorption cross-section spectrum of eosin Y in methanol has been determined by picosecond second harmonic Nd:glass laser excitation and time-delayed picosecond light continuum probing (probing wavelength region from 400 to 980 nm).

Cited by 39 publications

References 47 publications

Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Aqueous Solvation Dynamics at Metal Oxide Surfaces

Femtosecond Dynamics of Interfacial and Intermolecular Electron Transfer at Eosin-Sensitized Metal Oxide Nanoparticles

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