Related Experiment Video
Updated: Jun 3, 2026
06:44
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Marcus-like inversion in electron transfer in neat ionic liquid and ionic liquid-mixed micelles
Atanu Kumar Das1, Tridib Mondal, Supratik Sen Mojumdar
1Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India.
The Journal of Physical Chemistry. B
|April 7, 2011
Summary
Ultrafast electron transfer from N,N-dimethylaniline to coumarin dyes is slower in room-temperature ionic liquids (RTILs) due to viscosity. Adding Pluronic P123 enhances electron transfer and diffusion rates.
Area of Science:
- Photochemistry
- Physical Chemistry
- Materials Science
Background:
- Ultrafast photoinduced electron transfer (PET) is crucial for understanding charge separation dynamics.
- Room-temperature ionic liquids (RTILs) offer unique solvent properties for chemical reactions.
- Triblock copolymers like Pluronic P123 can form nanostructures influencing molecular behavior.
Purpose of the Study:
- To investigate the kinetics of PET from N,N-dimethylaniline (DMA) to coumarin dyes.
- To compare PET rates and diffusion in neat RTIL ([pmim][BF(4)]) versus an RTIL-Pluronic P123 mixed micelle.
- To elucidate the role of solvent viscosity and nanostructuring on electron transfer dynamics.
Main Methods:
- Femtosecond upconversion spectroscopy was employed to monitor ultrafast PET.
- Anisotropy decay measurements were used to study translational diffusion.
- System compositions included neat RTIL and a mixed micelle of RTIL and Pluronic P123.
Main Results:
- A Marcus-like inversion in PET rate was observed in the neat RTIL, attributed to high viscosity and nanostructuring.
- PET and diffusion were significantly slower in the neat RTIL compared to the RTIL-P123 mixed micelle.
- Coumarin dyes showed accelerated electron transfer and translational diffusion in the RTIL-P123 mixed micelle relative to P123 micelles alone.
Conclusions:
- The viscosity and nanostructure of RTILs play a critical role in modulating PET rates.
- The RTIL-P123 mixed micelle provides a more dynamic environment, enhancing both electron transfer and diffusion.
- Understanding these solvent effects is key for designing efficient photoactive systems.
Related Concept Videos
01:30Micelles
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
02:55Solubility of Ionic Compounds
Solubility is the measure of the maximum amount of solute that can be dissolved in a given quantity of solvent at a given temperature and pressure. Solubility is usually measured in molarity (M) or moles per liter (mol/L). A compound is termed soluble if it dissolves in water.
03:13Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...