Related Experiment Video
Updated: Aug 16, 2025
14:11
Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
6.3K
Al(III) and Ga(III) Bisphenolate Azadipyrromethene-Based "N2O2" Complexes as Efficient NIR-Fluorophores
Amélie Godard1, Laura Abad Galán2, Jean Rouillon2
1Institut de Chimie Moléculaire de l'Université de Bourgogne, Université Bourgogne Franche-Comté, CNRS UMR 6302, F-21000 Dijon, France.
Inorganic Chemistry
|December 21, 2022
Summary
New aza-boron-dipyrromethene (Aza-BODIPY) metal complexes with aluminum and gallium show red-shifted fluorescence up to 800 nm. These stable AzaGaDIPY and AzaAlDIPY fluorophores are promising for near-infrared optical medical imaging.
Area of Science:
- Organic Chemistry
- Materials Science
- Photophysics
Background:
- Aza-boron-dipyrromethenes (Aza-BODIPYs) are a class of fluorophores.
- Aza-BODIPYs can be viewed as an azadipyrromethene ligand stabilized by a boron atom.
- Investigating metal complexes of Aza-BODIPYs is crucial for developing new imaging agents.
Purpose of the Study:
- To synthesize and characterize novel group 13 metal complexes (aluminum and gallium) with aza-DIPY ligands.
- To investigate the impact of the metal center and substituents on the photophysical and electrochemical properties.
- To explore the potential of these new complexes as fluorophores for optical medical imaging.
Main Methods:
- Synthesis and characterization of aluminum and gallium aza-DIPY complexes.
- Photophysical measurements (absorption, emission spectra) and electrochemical analysis.
- X-ray crystallography and molecular modeling studies.
Main Results:
- Synthesized and characterized a series of aluminum and gallium aza-DIPY complexes.
- Observed significant red-shifted fluorescence for azaGaDIPY and azaAlDIPY compared to aza-BODIPYs, with emission up to 800 nm and NIR-II tail.
- Demonstrated excellent electrochemical stability, with no metal release upon oxidation or reduction.
- X-ray and modeling studies indicated that the observed redshift is primarily due to the metal coordination geometry rather than the metal type.
Conclusions:
- AzaGaDIPY and azaAlDIPY complexes represent a promising new class of red-shifted fluorophores.
- Their emission properties and electrochemical stability make them suitable for advanced optical medical imaging applications, particularly in the NIR-II window.
- The geometric arrangement around the metal center plays a key role in tuning the photophysical properties of these fluorophores.
Related Concept Videos
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
6.3K
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
6.3K
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
3.1K
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the...
3.1K
01:26Variables Affecting Phosphorescence and Fluorescence
568
Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...
568
01:14Photoluminescence: Applications
465
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
465
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.2K
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.2K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.0K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.0K