9，10-Diphenylanthracene (CAS: 1499-10-1) is a polycyclic aromatic hydrocarbon (PAH) that is widely studied for its unique chemical properties, including its ability to fluoresce and its high thermal and photochemical stability. This compound consists of a central anthracene backbone, a three-ring aromatic structure, substituted with phenyl groups at the 9 and 10 positions. Due to its conjugated structure, 9，10-Diphenylanthracene demonstrates distinct optical, electronic, and chemical behaviors that make it a valuable material in various fields such as organic electronics, material science, and chemical synthesis.
This article provides an in-depth analysis of the chemical properties, production process, and diverse applications of 9，10-Diphenylanthracene. Through a discussion of its structure, reactivity, and practical uses, we aim to highlight why this compound remains important in research and industry.
Chemical Properties of 9，10-Diphenylanthracene
Molecular Structure and Conjugation
The molecular structure of 9，10-Diphenylanthracene consists of a three-ring anthracene core with two phenyl groups attached to the 9 and 10 positions. This highly conjugated system, which delocalizes electrons across the aromatic rings, imparts significant stability to the compound. The arrangement of the phenyl groups at the 9 and 10 positions of anthracene increases the electron density of the molecule, enhancing its optical properties, such as fluorescence, and making it an excellent candidate for use in electronic and optoelectronic devices.
The conjugation across the three aromatic rings of anthracene and the two phenyl groups results in strong π-π interactions, which contribute to the compound’s ability to absorb and emit light. The extent of conjugation also ensures that 9，10-Diphenylanthracene is chemically stable, able to withstand various environmental conditions, including exposure to light and air.
Chemical Reactivity
As a polycyclic aromatic hydrocarbon (PAH), 9，10-Diphenylanthracene exhibits a range of typical reactivity seen in other aromatic compounds. The high electron density within its conjugated π-system makes it susceptible to electrophilic aromatic substitution reactions, such as halogenation, nitration, and sulfonation. However, due to the steric hindrance from the bulky phenyl groups, reactions tend to be more selective and occur primarily at positions that are not directly involved in conjugation.
9，10-Diphenylanthracene is also known for its ability to undergo photochemical reactions. Under UV light, the compound absorbs energy and enters an excited state, which can lead to various photophysical processes. The compound’s fluorescence properties are particularly significant, as it exhibits efficient emission of light when returning to its ground state. This makes it useful in a variety of applications, including fluorescent sensors and light-emitting devices.
Solubility and Hydrophobicity
9，10-Diphenylanthracene is a relatively hydrophobic compound, with low solubility in polar solvents like water, methanol, or ethanol. It is, however, soluble in non-polar organic solvents such as chloroform, toluene, and hexane. This solubility profile is important in the handling, purification, and processing of the compound, as it influences the choice of solvents for synthetic routes and final product formulations.
Stability and Degradation
The compound exhibits high thermal stability, remaining intact at elevated temperatures (up to around 400°C) without significant degradation. This makes it suitable for use in high-temperature environments or in applications where materials may be exposed to heat. Photochemically, while it is resistant to degradation under typical laboratory light conditions, prolonged exposure to ultraviolet (UV) radiation can cause degradation of its fluorescence properties. Therefore, protective measures are often employed when handling or utilizing the compound in UV-sensitive applications.
Production Process of 9，10-Diphenylanthracene
9，10-Diphenylanthracene is synthesized via several routes, with Friedel-Crafts alkylation and coupling reactions being among the most common methods. These methods are highly efficient, providing good yields with relatively simple reaction conditions.
Friedel-Crafts Alkylation
The Friedel-Crafts alkylation method is one of the oldest and most widely used approaches for synthesizing 9，10-Diphenylanthracene. In this process, anthracene reacts with a phenyl halide (such as bromobenzene) in the presence of a Lewis acid catalyst, typically aluminum chloride (AlCl₃). The Lewis acid activates the phenyl halide, generating a phenyl cation, which then undergoes an electrophilic substitution at the 9 and 10 positions of the anthracene molecule, resulting in the formation of 9，10-Diphenylanthracene.
The reaction is generally carried out in anhydrous conditions, as moisture can de-activate the catalyst and affect the reaction yield. After the reaction, the product is typically purified using recrystallization from an appropriate solvent, such as toluene or hexane.
Suzuki-Miyaura Coupling Reaction
An alternative, more selective approach for synthesizing 9，10-Diphenylanthracene involves the Suzuki-Miyaura coupling reaction. In this process, a phenylboronic acid derivative reacts with anthracene in the presence of a palladium catalyst. The reaction proceeds under mild conditions, allowing for a more controlled formation of the carbon-carbon bond between the phenyl group and the anthracene core. This approach offers better selectivity and can be carried out under relatively low temperatures, reducing the likelihood of side reactions.
Other Methods
Other methods, including oxidative coupling and radical coupling reactions, are occasionally used to synthesize 9，10-Diphenylanthracene. These methods often require special reaction conditions, such as high temperatures or the presence of specific oxidizing agents, but can provide high yields in some cases. These reactions are typically used when a more complex reaction scheme is required, or when the desired purity is more easily achieved using alternative synthetic strategies.
Applications of 9，10-Diphenylanthracene
9，10-Diphenylanthracene finds applications across a wide range of industries, primarily due to its fluorescence properties, conjugated structure, and stability. Below are some notable examples of its diverse uses.
1. Organic Light-Emitting Diodes (OLEDs)
Organic light-emitting diodes (OLEDs) are a critical component in modern display technologies and lighting systems. 9，10-Diphenylanthracene is often used as an emissive material in OLEDs due to its strong fluorescence and efficient light emission. In OLEDs, it serves as a light-emitting layer, where it emits blue light upon electrical excitation. The high quantum yield and photostability of 9，10-Diphenylanthracene make it suitable for use in displays that require high brightness and longevity.
In addition to light emission, the compound’s high thermal stability ensures that OLEDs containing 9，10-Diphenylanthracene can function efficiently over an extended period, even at higher operating temperatures. This makes it particularly valuable in consumer electronics such as smartphones, television screens, and wearables.
2. Fluorescent Sensors and Imaging
The fluorescence properties of 9，10-Diphenylanthracene make it ideal for use in fluorescent sensors. The compound’s fluorescence is sensitive to various environmental factors such as pH, solvent polarity, and the presence of metal ions, which can affect the emission wavelength or intensity. This property is exploited in chemical and biological sensing applications, where 9，10-Diphenylanthracene is used to detect specific analytes.
In biological systems, 9，10-Diphenylanthracene-based fluorescent probes have been developed to monitor cellular processes, detect biomolecules, or image biological tissues. These applications are valuable in medical diagnostics and in the development of laboratory research tools for studying cellular functions.
3. Organic Solar Cells (OPVs)
In the field of renewable energy, 9，10-Diphenylanthracene has been investigated as a material in organic photovoltaic (OPV) devices. OPVs convert light into electricity through the photovoltaic effect, and materials with conjugated structures, like 9，10-Diphenylanthracene, can act as either electron donors or acceptors in these systems.
While not typically used as the primary light-harvesting material, 9，10-Diphenylanthracene has been incorporated into OPVs as part of a composite or blend with other organic materials. Its role in these devices is to enhance the overall charge transport and increase the device’s efficiency.
4. Chemical Sensing and Environmental Monitoring
Due to its strong fluorescence, 9，10-Diphenylanthracene has also been used in chemical sensing applications. Its fluorescence can be modulated by interactions with different substances, making it useful for detecting pollutants, environmental toxins, or specific gases in the atmosphere. By measuring the changes in the emission properties of 9，10-Diphenylanthracene, sensors can offer real-time monitoring of environmental conditions.
In particular, sensors based on this compound are useful in monitoring the presence of hazardous chemicals in industrial settings or in outdoor environments.
5. Molecular Photochemistry
The photochemical properties of 9，10-Diphenylanthracene make it a candidate for use in molecular photochemistry, where light-induced reactions are employed to trigger specific chemical transformations. The compound can be used to study photo-induced reactions, and it has been incorporated into molecular photochemistry research due to its ability to undergo various light-induced processes, such as photoisomerization, photodimerization, and photoreduction. These properties make it a useful tool for understanding fundamental photochemical reactions and designing new materials with specific light-driven reactivity. In particular, 9，10-Diphenylanthracene is employed in research into photopolymerization processes, where its ability to absorb UV light and initiate chemical reactions is harnessed for the creation of polymer films and coatings.
Additionally, 9，10-Diphenylanthracene is sometimes used in photochemistry to study electron transfer processes and charge separation mechanisms. The photophysical properties of the compound, such as its excited-state behavior and photoluminescence, make it an excellent model molecule for these types of studies, which have applications in areas such as organic electronics, solar energy conversion, and molecular photodetectors.
6. Nanomaterials and Molecular Electronics
9，10-Diphenylanthracene has also attracted attention in the field of nanotechnology, where it is being explored as a building block for larger molecular structures, such as organic semiconductor nanomaterials. Due to its strong conjugated structure and the ability to interact with other molecules via π-π stacking interactions, 9，10-Diphenylanthracene can be incorporated into molecular aggregates, thin films, and other nanostructured materials.
In the development of organic semiconductors for use in flexible electronics, sensors, and molecular-scale devices, 9，10-Diphenylanthracene can serve as a key component due to its ability to transport charge and interact with other organic materials. These types of molecular materials are being investigated for use in the development of flexible displays, organic transistors, and integrated optoelectronic devices.
In addition, 9，10-Diphenylanthracene-based nanomaterials have shown promise in various catalytic processes. Its stable conjugated structure allows it to function as a catalyst or as part of a catalytic system, providing a platform for the development of sustainable and efficient catalytic processes in fields such as energy production and environmental remediation.
Applications in Environmental Sensing and Pollution Control
One of the key emerging applications of 9，10-Diphenylanthracene is in environmental monitoring and pollution control. Due to its high sensitivity to UV light and its fluorescence properties, it is an ideal candidate for use in detecting environmental pollutants, particularly in water and air quality monitoring.
For example, 9，10-Diphenylanthracene has been used in sensors designed to detect heavy metals, such as mercury or lead, in aqueous solutions. When these metals bind to the compound, they alter its fluorescence characteristics, allowing for the detection of trace amounts of contaminants. This sensitivity to metals makes it an excellent choice for the development of low-cost, portable environmental sensors that can be used in remote locations or on-site monitoring in industries such as mining, agriculture, and manufacturing.
In air quality monitoring, 9，10-Diphenylanthracene-based sensors have been developed to detect toxic gases like carbon monoxide, nitrogen dioxide, and ozone. The fluorescence response of 9，10-Diphenylanthracene changes in the presence of these gases, allowing for real-time measurement of air pollution levels. Such sensors have the potential to be integrated into smart cities or environmental monitoring systems to help address the challenges posed by air pollution and climate change.
Applications in Chemical Synthesis and Drug Discovery
In addition to its environmental applications, 9，10-Diphenylanthracene plays an important role in chemical synthesis, particularly as an intermediate in the production of other organic compounds. Due to its electron-rich nature, it can participate in a variety of chemical reactions, such as electrophilic aromatic substitution and nucleophilic aromatic substitution, making it a valuable building block in organic synthesis.
In drug discovery, the fluorescence properties of 9，10-Diphenylanthracene have been leveraged to design screening platforms for identifying novel bioactive compounds. The compound’s ability to selectively bind to specific biomolecules and change its fluorescence spectrum is useful in high-throughput screening assays, where researchers can identify new leads for pharmaceutical development.
Moreover, 9，10-Diphenylanthracene has been incorporated into targeted drug delivery systems. Its conjugation with other functionalized molecules allows for the creation of nanocarriers that can deliver drugs to specific tissues or cells, based on the molecule’s ability to interact with biological markers. This approach has potential applications in cancer therapy, where targeted drug delivery is crucial for minimizing side effects and improving therapeutic efficacy.
Research Trends and Future Directions
The study of 9，10-Diphenylanthracene has expanded significantly in recent years, driven by its unique combination of chemical, physical, and photochemical properties. Researchers continue to explore its applications in emerging fields such as organic electronics, photonic devices, and sustainable energy systems.
One promising area of research is the use of 9，10-Diphenylanthracene in the development of next-generation optoelectronic devices, such as flexible OLEDs and organic solar cells. Researchers are investigating ways to optimize the light-emitting efficiency, stability, and scalability of 9，10-Diphenylanthracene-based devices. The combination of high fluorescence, thermal stability, and solution-processability makes it an attractive candidate for future commercial applications in displays and lighting technologies.
In the realm of environmental sensing, there is also growing interest in improving the sensitivity and selectivity of 9，10-Diphenylanthracene-based sensors. For instance, modifying the structure of the compound by introducing functional groups could enhance its interaction with specific pollutants, providing more sensitive detection methods for environmental monitoring. Moreover, the integration of these sensors into wireless, real-time data collection systems has the potential to revolutionize air and water quality monitoring in both industrial and residential settings.
Finally, the potential of 9，10-Diphenylanthracene in drug delivery and medical imaging continues to be an area of active research. By combining its optical properties with targeted drug delivery techniques, researchers hope to develop new treatments for diseases like cancer, where precision targeting is key to minimizing toxicity and improving treatment outcomes.
Conclusion
9，10-Diphenylanthracene (CAS: 1499-10-1) is a highly versatile and interesting compound, whose chemical, photophysical, and thermal properties have made it a valuable material in a variety of applications. Its unique structure, with its conjugated π-system and phenyl substitutions, allows it to exhibit remarkable fluorescence, stability, and reactivity. These properties have led to its use in organic electronics, sensors, photovoltaics, molecular electronics, and even in chemical synthesis and drug discovery.
From its role in OLEDs and organic solar cells to its applications in environmental monitoring, molecular photochemistry, and nanomaterials, 9，10-Diphenylanthracene continues to be an important compound in both academic and industrial research. As technology advances and new research develops, the applications of 9，10-Diphenylanthracene are likely to expand further, contributing to innovations in electronics, energy, environmental science, and healthcare. The compound’s combination of fluorescence, stability, and versatility will undoubtedly play a significant role in shaping the future of organic materials and advanced technologies. Researchers will continue to explore new ways to optimize and harness its properties, opening up new possibilities for its use in a wide range of industries. Whether in flexible electronics, environmental sensors, or targeted drug delivery, 9，10-Diphenylanthracene is a compound with vast potential that will likely remain at the forefront of scientific and technological progress for years to come.