Related Experiment Video
Updated: Jan 23, 2026
05:51
Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes
Published on: November 15, 2016
8.4K
Emissive Organic Exciplexes in Water
Joseph P Dinnocenzo1, Analuz Mark1, Samir Farid1
1Department of Chemistry , University of Rochester , Rochester , New York 14627 , United States.
The Journal of Organic Chemistry
|June 12, 2019
Summary
Researchers created novel cationic exciplexes from organic molecules in water. These emissive exciplexes exhibit high charge transfer character and luminescence, even in polar solvents.
Area of Science:
- Organic Chemistry
- Photochemistry
- Supramolecular Chemistry
Background:
- Cationic exciplexes, products of charge shift reactions, are less common than charge formation exciplexes.
- Previous work demonstrated N-methylisoquinolinium and alkyl benzenes can form cationic exciplexes.
Purpose of the Study:
- To synthesize and characterize intramolecular analogues of cationic exciplexes.
- To demonstrate the formation of emissive exciplexes in water from purely organic components.
- To investigate the influence of donor hydrophobicity on exciplex formation.
Main Methods:
- Synthesis of five intramolecular analogues.
- Absorption spectroscopy and fluorometry.
- Time-correlated single photon counting.
Main Results:
- Identification of three conformers (anti, gauche, folded) facilitating electron transfer.
- Hydrophobicity of the donor moiety enhances folded conformer formation and exciplex generation.
- High charge transfer (CT) character (88-97%) observed.
- Exciplex fluorescence quantum yields up to 0.03 and lifetimes up to 17 ns in a polar solvent.
Conclusions:
- Emissive cationic exciplexes can be formed in water using purely organic molecules.
- Conformational control and donor hydrophobicity are key factors in exciplex formation.
- These findings advance the understanding of charge shift reactions and exciplex behavior in polar environments.
Related Concept Videos
02:39Emission Spectra
75.9K
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present.
75.9K
01:23States of Water
56.5K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
56.5K
01:29Positron Emission Tomography
7.0K
Positron emission tomography (PET) is a medical imaging technique involving radiopharmaceuticals — substances that emit short-lived radiation. Although the first PET scanner was introduced in 1961, it took 15 more years before radiopharmaceuticals were combined with the technique and revolutionized its potential.
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...
7.0K
01:31Accessory Organs
74.0K
Accessory organs are those that participate in the digestion of food but do not come into direct contact with it like the mouth, stomach, or intestine do. Accessory organs secrete enzymes into the digestive tract to facilitate the breakdown of food.
74.0K
02:34Water and Mineral Acquisition
35.4K
Specialized tissues in plant roots have evolved to capture water, minerals, and some ions from the soil. Roots exhibit a variety of branching patterns that facilitate this process. The outermost root cells have specialized structures called root hairs that increase the root surface, thus increasing soil contact. Water can passively cross into roots, as the concentration of water in the soil is higher than that of the root tissue. Minerals, in contrast, are actively transported into root cells.
35.4K
01:19Quality of Water
513
In concrete preparation, the quality of water is paramount as it affects the strength and durability of the concrete. Potable water is usually preferred; however, it must not have excessive sodium or potassium to prevent compromising the concrete's integrity. Water quality is typically evaluated based on impurities such as dissolved solids, chlorides, and sulfates, and its pH value is ideally between 6 and 8. Even slightly acidic natural water may be acceptable unless it contains harmful...
513