Related Experiment Video
Updated: Mar 2, 2026
08:12
Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance
Published on: September 5, 2018
16.6K
Rational Design of Stable Dianions by Functionalizing Polycyclic Aromatic Hydrocarbons
Mingmin Zhong1,2, Jian Zhou2, Puru Jena2
1School of Physical Science and Technology, Southwest University, Chongqing, 400715, China.
Summary
Researchers explored stable dianions in modified naphthalene molecules (BnC10-nX8). Replacing hydrogen with electronegative groups like cyanide (CN) significantly enhanced dianion stability, enabling new multiply charged organic molecules.
Area of Science:
- Computational Chemistry
- Materials Science
- Organic Electronics
Background:
- Naphthalene (C10H8) is a fundamental polycyclic aromatic hydrocarbon.
- Understanding the stability of multiply charged organic molecules is crucial for novel electronic materials.
- Previous studies have explored modifications of polycyclic aromatic hydrocarbons for enhanced stability.
Purpose of the Study:
- To investigate the stability and electronic properties of neutral and multiply charged BnC10-nX8 molecules.
- To determine if core carbon or hydrogen atom substitutions in naphthalene enhance dianion stability.
- To explore the potential for designing organic molecules capable of carrying multiple charges.
Main Methods:
- Systematic study using density functional theory (DFT).
- Calculations focused on neutral and multiply charged states of BnC10-nX8 (n=0, 1, 2; X=H, F, CN).
- Analysis of electronic properties and stability energies.
Main Results:
- Dianions of BnC10-n(CN)8 exhibit enhanced stability compared to their monoanions.
- Stability energies for dianions were found to be 0.61 eV (n=0), 0.57 eV (n=1), and 1.97 eV (n=2).
- Polycyclic aromatic hydrocarbon dianions become stable when hydrogen atoms are replaced by more electronegative species like CN.
Conclusions:
- Rational molecular design by tailoring composition and ligands can create stable, multiply charged organic molecules.
- Substitution with electronegative ligands is key to stabilizing polycyclic aromatic hydrocarbon dianions.
- This work opens avenues for developing new classes of organic materials with unique charge-carrying capabilities.
Related Concept Videos
01:18Aromatic Hydrocarbon Anions: Structural Overview
4.1K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
Due to the absence of continuous...
4.1K
01:18Aromatic Hydrocarbon Cations: Structural Overview
4.1K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
Removing one hydrogen from the intervening CH2 group...
4.1K
01:28Stability of Conjugated Dienes
4.6K
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
4.6K
01:19Diazonium Group Substitution: –OH and –H
3.4K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
3.4K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.6K
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...
2.6K
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.8K
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,...
2.8K