Related Experiment Video
Updated: Jan 29, 2026
05:47
Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
8.1K
On the Mechanism of Phenolate Photo-Oxidation in Aqueous Solution
Alexandra L Tyson1, Jan R R Verlet1
1Department of Chemistry , Durham University , Durham DH1 3LE , U.K.
The Journal of Physical Chemistry. B
|February 16, 2019
Summary
Ultraviolet light causes electron ejection from phenolate anions in water, forming hydrated electrons. This photo-oxidation process is faster than previously reported, differing based on excitation energy.
Area of Science:
- Photochemistry
- Physical Chemistry
- Spectroscopy
Background:
- The photo-oxidation of anions is crucial for understanding electron transfer processes.
- Previous studies on phenolate photo-oxidation showed slower electron emission dynamics.
Purpose of the Study:
- To investigate the ultrafast photo-oxidation dynamics of phenolate anions.
- To compare electron ejection mechanisms between phenolate and iodide.
- To elucidate the role of excitation energy in electron emission.
Main Methods:
- Broadband transient absorption spectroscopy (550-950 nm).
- Ultraviolet (257 nm) excitation of aqueous phenolate anion solutions.
Main Results:
- Observed sub-picosecond electron ejection from phenolate.
- Identified cooling dynamics and formation of hydrated electrons.
- Found dynamics similar to iodide charge-transfer-to-solvent but differing from previous phenolate studies.
- Demonstrated excitation energy dependence of electron emission rates via Marcus theory.
Conclusions:
- Phenolate photo-oxidation dynamics are highly sensitive to excitation wavelength.
- Electron emission and subsequent solvation exhibit similarities between phenolate and iodide systems.
- The Marcus picture effectively explains excitation energy-dependent electron tunneling rates.
Related Concept Videos
03:03Chemical Reactions in Aqueous Solutions
72.2K
Chemical substances interact in many different ways. Certain chemical reactions exhibit common patterns of reactivity. Due to the vast number of chemical reactions, it becomes necessary to classify them based on the observed patterns of interaction.
72.2K
02:42Aqueous Solutions and Heats of Hydration
17.9K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
17.9K
01:17Oxidation of Phenols to Quinones
4.7K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
4.7K
02:11Leveling Effect and Non-Aqueous Acid-Base Solutions
9.4K
This lesson defines the leveling effect in acidic and basic solutions and its role in aqueous and non-aqueous solutions. It is essential to understand the competing nature of various species in a chemical system.
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
9.4K
02:12General Properties of Solutions
35.7K
Many common substances around us exist as a solution, such as ocean water, air, and gasoline. All solutions are mixtures of substances that are composed of varying amounts of two or more types of atoms or molecules. A mixture with a non-uniform composition is a heterogeneous mixture, whereas a mixture with a uniform composition is a homogeneous mixture. The components that make the homogeneous mixture are evenly spread out and thoroughly mixed.
35.7K
02:16Solution Formation
37.4K
There is no one solvent that can dissolve every type of solute. Some substances that readily dissolve in a certain solvent might be insoluble in a different solvent. A simple way to predict which substances dissolve in which solvent is the phrase "like dissolves like". This means that polar substances, such as salt and sugar, dissolve in a polar substance like water. In contrast, non-polar substances are more soluble in non-polar solvents such as carbon tetrachloride.
This selective...
This selective...
37.4K