Role of Solvation Dynamics in Excited State Proton Transfer of 1-Naphthol in Nanoscopic Water Clusters Formed in a Hydrophobic Solvent

Excited state proton transfer (ESPT) in biologically relevant organic molecules in aqueous environments following photoexcitation is very crucial as the reorganization of polar solvents (solvation) in the locally excited (LE) state of the organic molecule plays an important role in the overall rate...

Full description

Saved in:
Bibliographic Details
Published in:Photochemistry and photobiology 2012-07, Vol.88 (4), p.851-859
Main Authors: Rakshit, Surajit, Saha, Ranajay, Verma, Pramod Kumar, Pal, Samir Kumar
Format: Article
Language:English
Subjects:
Chemical compounds
Coumarins
Fluorescent Dyes
Hydrogen - chemistry
Hydrogen Bonding
Hydrophobic and Hydrophilic Interactions
Kinetics
Models, Molecular
Molecular structure
Naphthols - chemistry
Photochemistry
Protons
Solubility
Solvents
Spectrometry, Fluorescence
Temperature
Thermodynamics
Time Factors
Water
Water - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Excited state proton transfer (ESPT) in biologically relevant organic molecules in aqueous environments following photoexcitation is very crucial as the reorganization of polar solvents (solvation) in the locally excited (LE) state of the organic molecule plays an important role in the overall rate of the ESPT process. A clear evolution of the two photoinduced dynamics in a model ESPT probe 1‐naphthol (NpOH) upon ultrafast photoexcitation is the motive of the present study. Herein, the detailed kinetics of the ESPT reaction of NpOH in water clusters formed in hydrophobic solvent are investigated. Distinct values of time constants associated with proton transfer and solvent relaxation have been achieved through picosecond‐resolved fluorescence measurements. We have also used a model solvation probe Coumarin 500 (C500) to investigate the dynamics of solvation in the same environmental condition. The temperature dependent picosecond‐resolved measurement of ESPT of NpOH and the dynamics of solvation from C500 identify the magnitude of intermolecular hydrogen bonding energy in the water cluster associated with the ultrafast ESPT process. The detailed kinetics of excited‐state proton transfer and associated relaxation dynamics of water around the probe 1‐naphthol in the nanoclusters of water in dioxane has been investigated.
ISSN:0031-8655
1751-1097
DOI:10.1111/j.1751-1097.2012.01140.x