Excited-State Proton-Transfer Processes of DHICA Resolved: From Sub-Picoseconds to Nanoseconds

Alice Corani; Alessandro Pezzella; Torbjörn Passcher; Thomas Gustavsson; Dimitra Markovitsi; Annemarie Huijser; Marco D'Ischia; Villy Sundström

doi:10.1021/jz400437q

Excited-State Proton-Transfer Processes of DHICA Resolved: From Sub-Picoseconds to Nanoseconds

Alice Corani, Alessandro Pezzella, Torbjörn Passcher, Thomas Gustavsson, Dimitra Markovitsi, Annemarie Huijser, Marco D'Ischia, Villy Sundström^*

^*Corresponding author for this work

Faculty of Science and Technology

Research output: Contribution to journal › Article › Academic › peer-review

40 Citations (Scopus)

10 Downloads (Pure)

Abstract

Excited-state proton transfer has been hypothesized as a mechanism for UV energy dissipation in eumelanin skin pigments. By using time-resolved fluorescence spectroscopy, we show that the previously proposed, but unresolved, excited-state intramolecular proton transfer (ESIPT) of the eumelanin building block 5,6-dihydroxyindole-2-carboxylic acid (DHICA) occurs with a time constant of 300 fs in aqueous solution but completely stops in methanol. The previously disputed excited-state proton transfer involving the 5- or 6-OH groups of the DHICA anion is now found to occur from the 6-OH group to aqueous solvent with a rate constant of 4.0 × 108 s

Original language	English
Pages (from-to)	1383-1388
Number of pages	6
Journal	The journal of physical chemistry letters
Volume	4
Issue number	9
DOIs	https://doi.org/10.1021/jz400437q
Publication status	Published - 2013

Keywords

n/a OA procedure

Access to Document

10.1021/jz400437q

Cite this

@article{cf9f493a564a470f89b766bdd0469212,

title = "Excited-State Proton-Transfer Processes of DHICA Resolved: From Sub-Picoseconds to Nanoseconds",

abstract = "Excited-state proton transfer has been hypothesized as a mechanism for UV energy dissipation in eumelanin skin pigments. By using time-resolved fluorescence spectroscopy, we show that the previously proposed, but unresolved, excited-state intramolecular proton transfer (ESIPT) of the eumelanin building block 5,6-dihydroxyindole-2-carboxylic acid (DHICA) occurs with a time constant of 300 fs in aqueous solution but completely stops in methanol. The previously disputed excited-state proton transfer involving the 5- or 6-OH groups of the DHICA anion is now found to occur from the 6-OH group to aqueous solvent with a rate constant of 4.0 × 108 s",

keywords = "n/a OA procedure",

author = "Alice Corani and Alessandro Pezzella and Torbj{\"o}rn Passcher and Thomas Gustavsson and Dimitra Markovitsi and Annemarie Huijser and Marco D'Ischia and Villy Sundstr{\"o}m",

year = "2013",

doi = "10.1021/jz400437q",

language = "English",

volume = "4",

pages = "1383--1388",

journal = "The journal of physical chemistry letters",

issn = "1948-7185",

publisher = "American Chemical Society",

number = "9",

}

TY - JOUR

T1 - Excited-State Proton-Transfer Processes of DHICA Resolved

T2 - From Sub-Picoseconds to Nanoseconds

AU - Corani, Alice

AU - Pezzella, Alessandro

AU - Passcher, Torbjörn

AU - Gustavsson, Thomas

AU - Markovitsi, Dimitra

AU - Huijser, Annemarie

AU - D'Ischia, Marco

AU - Sundström, Villy

PY - 2013

Y1 - 2013

N2 - Excited-state proton transfer has been hypothesized as a mechanism for UV energy dissipation in eumelanin skin pigments. By using time-resolved fluorescence spectroscopy, we show that the previously proposed, but unresolved, excited-state intramolecular proton transfer (ESIPT) of the eumelanin building block 5,6-dihydroxyindole-2-carboxylic acid (DHICA) occurs with a time constant of 300 fs in aqueous solution but completely stops in methanol. The previously disputed excited-state proton transfer involving the 5- or 6-OH groups of the DHICA anion is now found to occur from the 6-OH group to aqueous solvent with a rate constant of 4.0 × 108 s

AB - Excited-state proton transfer has been hypothesized as a mechanism for UV energy dissipation in eumelanin skin pigments. By using time-resolved fluorescence spectroscopy, we show that the previously proposed, but unresolved, excited-state intramolecular proton transfer (ESIPT) of the eumelanin building block 5,6-dihydroxyindole-2-carboxylic acid (DHICA) occurs with a time constant of 300 fs in aqueous solution but completely stops in methanol. The previously disputed excited-state proton transfer involving the 5- or 6-OH groups of the DHICA anion is now found to occur from the 6-OH group to aqueous solvent with a rate constant of 4.0 × 108 s

KW - n/a OA procedure

U2 - 10.1021/jz400437q

DO - 10.1021/jz400437q

M3 - Article

SN - 1948-7185

VL - 4

SP - 1383

EP - 1388

JO - The journal of physical chemistry letters

JF - The journal of physical chemistry letters

IS - 9

ER -

Excited-State Proton-Transfer Processes of DHICA Resolved: From Sub-Picoseconds to Nanoseconds

Abstract

Keywords

Access to Document

Fingerprint

Cite this