1-Hexadecyl-2-[3-(1-hexadecyl-1,3-dihydro-3,3-dimethyl-2H-indol-2-ylidene)-1-propen-1-yl]-3,3-dimethyl-3H-indolium
[CAS# 78566-75-3]

Identification

• Classification: Organic raw materials >> Heterocyclic compound >> Indoles
• Name: 1-Hexadecyl-2-[3-(1-hexadecyl-1,3-dihydro-3,3-dimethyl-2H-indol-2-ylidene)-1-propen-1-yl]-3,3-dimethyl-3H-indolium
• Molecular Formula: C₅₅H₈₉N₂
• Molecular Weight: 778.32
• CAS Registry Number: 78566-75-3
• SMILES: CCCCCCCCCCCCCCCCN1C2=CC=CC=C2C(C1=CC=CC3=[N+](C4=CC=CC=C4C3(C)C)CCCCCCCCCCCCCCCC)(C)C

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P270-P271-P280-P301+P312-P302+P352-P304+P340-P305+P351+P338-P330-P332+P313-P337+P313-P362-P403+P233-P405-P501

Discovory and Applicatios

1-Hexadecyl-2-[3-(1-hexadecyl-1,3-dihydro-3,3-dimethyl-2H-indol-2-ylidene)-1-propen-1-yl]-3,3-dimethyl-3H-indolium is an indolium-based cationic dye with a complex molecular structure that incorporates two indoline or indolium moieties connected through a conjugated propenyl bridge. Each indolium unit is substituted with long hexadecyl alkyl chains at the 1-position and geminal dimethyl groups at the 3-position of the indoline ring, while one of the indolium nitrogen atoms carries a positive charge, balanced typically by a counterion such as iodide or chloride. The molecule is highly hydrophobic due to the long alkyl chains and features an extended π-conjugated system that imparts strong absorption and fluorescence properties.

This compound is primarily used in photophysical and optoelectronic applications, including as a component in near-infrared (NIR) dyes, organic photovoltaic devices, and fluorescent probes. The extended conjugation between the indolium units enables strong light absorption in the visible to near-infrared region, while the positively charged indolium centers facilitate solubility in polar solvents and interactions with negatively charged substrates or membranes. Its amphiphilic character, with long hydrophobic chains, also allows incorporation into micellar systems or lipid-based formulations.

In addition, such indolium-based dyes are utilized in the development of fluorescent probes for bioimaging. The molecule’s fluorescence can be tuned through structural modifications, and its cationic nature facilitates targeting of negatively charged cellular components or membranes, making it useful for cellular imaging, photodynamic studies, and sensor applications.

Synthetically, this type of compound is typically prepared through the condensation of 1,3-dihydro-3,3-dimethyl-2H-indol-1-hexadecyl derivatives with conjugated aldehydes or ketones to form the propenyl-bridged indolium system, followed by quaternization at the nitrogen atom to generate the positively charged indolium. The synthesis requires careful control to preserve the conjugation and to obtain the desired stereochemistry of the double bond in the propenyl bridge.

Overall, 1-Hexadecyl-2-[3-(1-hexadecyl-1,3-dihydro-3,3-dimethyl-2H-indol-2-ylidene)-1-propen-1-yl]-3,3-dimethyl-3H-indolium is a highly conjugated, amphiphilic indolium dye. Its combination of cationic character, extended π-system, and hydrophobic alkyl chains makes it a valuable compound for NIR dyes, fluorescent probes, optoelectronic materials, and bioimaging applications.