1-(4-Aminophenyl)-1,2,2-triphenylethene: Handling & Application Guide

1-(4-Aminophenyl)-1,2,2-triphenylethene is a tetraphenylethylene (TPE)-based aggregation-induced emission (AIE) active compound bearing a primary amine functional group, making it a versatile building block for fluorescent probes, biosensors, and functional material development.

Chemical Name

1-(4-Aminophenyl)-1,2,2-triphenylethene

SKU / Product Code

B300977

Core Structural Motif

Tetraphenylethylene (TPE) with a para-amino substituent

Key Photophysical Property

Aggregation-Induced Emission (AIE) active — weakly emissive in solution, strongly emissive in the aggregated state

Reactive Handle

Primary aromatic amine (-NH2), suitable for coupling reactions, Schiff base formation, and further functionalization

Typical Research Applications

Fluorescent probes, chemodosimeters, biosensors, AIE-based functional materials

Chemical Identity and Structural Features

1-(4-Aminophenyl)-1,2,2-triphenylethene (SKU: B300977) is a member of the tetraphenylethylene (TPE) family, one of the most extensively studied classes of aggregation-induced emission (AIE) luminogens. The compound consists of a central ethylenic double bond bearing four aryl substituents, three of which are unsubstituted phenyl rings and one of which is a 4-aminophenyl group. This asymmetric substitution distinguishes it from the parent TPE molecule and introduces a reactive primary amine handle.

The amine group at the para position is nucleophilic and can participate in a broad range of chemical transformations, including imine (Schiff base) condensation, acylation, sulfonylation, and coupling with activated electrophiles. This reactivity enables researchers to use 1-(4-Aminophenyl)-1,2,2-triphenylethene as a platform for constructing functionalised AIE probes with tailored selectivity toward specific analytes or biological targets.

The restricted intramolecular rotation (RIR) mechanism responsible for AIE behaviour in TPE derivatives arises from the four phenyl rotors flanking the alkene core. In dilute solution, rapid rotation of the phenyl rings dissipates excited-state energy non-radiatively, resulting in weak emission. Upon aggregation or immobilisation — for instance, when incorporated into a polymer matrix, bound to a protein, or precipitated in a poor solvent — rotation is suppressed and strong fluorescence is observed.

Recommended Handling, Storage, and Safety

Storage: Store 1-(4-Aminophenyl)-1,2,2-triphenylethene in a tightly sealed container in a cool, dry, and well-ventilated area, away from light, heat, and oxidising agents. Refrigerated storage (2–8 °C) is generally recommended for long-term preservation of amine-containing aromatic compounds to minimise oxidation and moisture uptake. Confirm optimal storage conditions from the product datasheet upon receipt.

Handling: Work under a fume hood when weighing or dissolving the compound. Avoid generating dust; use appropriate respiratory protection if dust generation cannot be prevented. Wear chemical-resistant gloves, safety goggles, and a laboratory coat. Aromatic amines as a chemical class warrant attention regarding potential sensitisation; consult the Safety Data Sheet (SDS) before use.

Solvents: TPE-based compounds are typically soluble in common organic solvents such as dichloromethane, chloroform, tetrahydrofuran, dimethyl sulfoxide (DMSO), and dimethylformamide (DMF). Solubility in aqueous media is limited; prepare stock solutions in DMSO or DMF and dilute into aqueous buffers immediately before use to minimise pre-aggregation artefacts in biological assays.

Disposal: Dispose of all waste containing this compound in accordance with applicable local, institutional, and governmental regulations for organic chemical waste.

Research Applications and Functionalization Strategies

Fluorescent probe construction: The primary amine group of 1-(4-Aminophenyl)-1,2,2-triphenylethene serves as the key reactive handle for probe synthesis. Reaction with aldehydes or ketones yields Schiff base (imine) derivatives; the resulting change in conjugation and restriction of intramolecular motion can be exploited to create turn-on or ratiometric fluorescent sensors for metal ions, reactive oxygen species (ROS), or biomolecules such as sugars and proteins.

Polymer and material science: The amine functionality allows integration of this AIE unit into polyamides, polyimides, epoxy networks, and metal-organic frameworks (MOFs) via standard condensation or coordination chemistry. The resulting materials display solid-state fluorescence, which can be applied in luminescent coatings, anti-counterfeiting inks, and optical waveguides.

Biological and biomedical research: TPE-amine derivatives have been reported as probes for monitoring protein aggregation (e.g., amyloid fibrillation), cell imaging, and detection of nucleic acids. The AIE character ensures that the probe becomes emissive specifically upon interaction with the target biomolecule or cellular structure, providing a low-background signal advantageous for wash-free imaging protocols.

Chemodosimetric sensing: The amine can be selectively acylated, alkylated, or reacted with reactive electrophiles to yield precursor chemodosimeters that undergo irreversible, analyte-triggered transformations accompanied by a detectable fluorescence change, offering high selectivity for target species such as electrophilic toxins or reactive gas molecules.

Quality Specifications and Analytical Verification

Researchers should verify the identity and purity of 1-(4-Aminophenyl)-1,2,2-triphenylethene upon receipt using standard analytical techniques. Recommended verification methods include:

• Nuclear Magnetic Resonance (NMR) Spectroscopy: ¹H and ¹³C NMR in deuterated solvents (e.g., CDCl₃ or DMSO-d₆) confirm the structural identity of the compound, particularly the aromatic proton pattern and the exchangeable NH₂ signal.
• High-Performance Liquid Chromatography (HPLC): Reverse-phase HPLC with UV detection provides a direct measure of purity. A purity specification of ≥95% (or as stated on the Certificate of Analysis, CoA) is typical for research-grade material.
• Mass Spectrometry (MS): ESI-MS or APCI-MS confirms the molecular ion, allowing unambiguous identification. Verify the observed m/z against the expected molecular formula.
• Melting Point: Comparison with literature or CoA values provides a rapid purity indicator for solid samples.

Always request and review the Certificate of Analysis (CoA) associated with the specific lot number of product received. Contact Aladdin Scientific technical support if analytical data deviate from expected specifications.

Frequently asked questions

What solvents are suitable for dissolving 1-(4-Aminophenyl)-1,2,2-triphenylethene?

This compound is typically soluble in polar aprotic organic solvents such as DMSO, DMF, THF, dichloromethane, and chloroform. It has limited water solubility due to its largely hydrophobic tetraphenylethylene scaffold. For biological assays, prepare a concentrated stock in DMSO and perform a final dilution into aqueous buffer immediately before use to control aggregation state.

Why does 1-(4-Aminophenyl)-1,2,2-triphenylethene show weak fluorescence in dilute solution but strong emission in the solid state or aggregated form?

This behaviour is characteristic of aggregation-induced emission (AIE), driven by the restriction of intramolecular rotation (RIR) mechanism. In dilute solution the four phenyl groups rotate freely around the central double bond, dissipating excited-state energy as heat (non-radiative decay). Upon aggregation, this rotation is physically restricted, forcing excited-state energy to be released as light (radiative decay) and resulting in bright fluorescence.

How can the primary amine group of this compound be used in probe or material synthesis?

The para-amino group is a versatile nucleophilic handle. It can condense with aldehydes or ketones to form Schiff base (imine) linkages for analyte-responsive probes; react with acyl chlorides or anhydrides to produce amide-linked conjugates; couple with activated NHS esters for bioconjugation; or be incorporated into polymer backbones via condensation polymerisation. Each transformation extends the AIE scaffold with new recognition or functional elements.

What precautions should be taken when handling aromatic amine compounds like this reagent?

Aromatic amines should be handled with care. Always work in a well-ventilated fume hood, wear nitrile or neoprene gloves, safety goggles, and a lab coat. Avoid inhalation of dust or vapours. Review the product Safety Data Sheet (SDS) before use for specific hazard classifications and first-aid measures. Dispose of waste according to local regulations for organic chemical waste.

References

1. Hong, Y.; Lam, J. W. Y.; Tang, B. Z. Aggregation-induced emission. Chemical Society Reviews, 2011, 40(11), 5361–5388. doi:10.1039/c1cs15113d
2. Mei, J.; Leung, N. L. C.; Kwok, R. T. K.; Lam, J. W. Y.; Tang, B. Z. Aggregation-Induced Emission: Together We Shine, United We Soar! Chemical Reviews, 2015, 115(21), 11718–11940. doi:10.1021/acs.chemrev.5b00263
3. Luo, J.; Xie, Z.; Lam, J. W. Y.; Cheng, L.; Tang, B. Z. et al. Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole. Chemical Communications, 2001, (18), 1740–1741. doi:10.1039/b105159h

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.