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Functional [6]pericyclynes: aromatization to substituted carbo-benzenes
Catherine Saccavini1, Christine Sui-Seng, Luc Maurette
1Laboratoire de Chimie de Coordination du CNRS, UPR 8241, 205 Route de Narbonne 31 077, Toulouse cedex 4, France.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|March 21, 2007
Summary
Researchers developed new synthetic routes to carbo-benzenes, demonstrating their aromaticity and potential for nonlinear optical applications. These C(18) ring systems show independent aromaticity, confirmed by structural and magnetic criteria.
Area of Science:
- Organic Chemistry
- Materials Science
- Computational Chemistry
Background:
- Carbo-benzenes are novel carbon-rich aromatic systems.
- Previous synthesis and characterization of substituted carbo-benzenes were limited.
- Understanding the aromaticity and properties of carbo-benzenes is crucial for their application.
Purpose of the Study:
- To explore new synthetic pathways for substituted carbo-benzenes.
- To investigate the nonlinear optical properties of specific hexaaryl-carbo-benzenes.
- To confirm the independent aromaticity of the carbo-benzene ring system.
Main Methods:
- Reductive treatment of hexaoxy[6]pericyclynes using SnCl(2)/HCl.
- Aromatization of pericyclynetetrol precursors.
- Characterization using X-ray crystallography, NMR spectroscopy (1H, 13C), and Mass Spectrometry.
- Density Functional Theory (DFT) calculations (B3PW91/6-31G**, B3LYP/6-31+G**).
Main Results:
- Successfully synthesized various substituted carbo-benzenes, including hexaphenyl-carbo-benzene derivatives.
- Demonstrated alternative precursors for hexaphenyl-carbo-benzene synthesis.
- Synthesized a hexaaryl-carbo-benzenic chromophore with potential for nonlinear optical applications.
- Confirmed the compatibility of alkynyl substituents with the carbo-benzene ring.
- Isolated and characterized protected and partially unsubstituted carbo-benzenes.
- Experimental and theoretical data confirmed the independent aromaticity of the carbo-benzene ring.
Conclusions:
- Reductive treatment of pericyclynes is an effective method for synthesizing carbo-benzenes.
- Carbo-benzenes exhibit strong diatropic ring currents, confirming their aromatic nature.
- The carbo-benzene core is a stable and versatile scaffold for developing new materials with tunable properties.
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