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Dianion Stabilization by (M(C5(CH3)5)2)+: Theoretical Evidence for a Localized Ring in (DDQ)2-
Science (New York, N.Y.)
|February 20, 1987
Summary
Researchers stabilized organic dianions using iron or cobalt complexes, enabling detailed structural and spectroscopic analysis. X-ray crystallography revealed a localized ring structure for the 2,3-dichloro-5,6-dicyanobenzoquinone dianion.
Area of Science:
- Organometallic Chemistry
- Inorganic Chemistry
- Organic Chemistry
Background:
- Stabilization of organic dianions is challenging due to their high reactivity.
- Previous studies have explored various methods for stabilizing reactive organic species.
Purpose of the Study:
- To synthesize and characterize novel organic dianions.
- To investigate the structural and electronic properties of these stabilized dianions.
Main Methods:
- Synthesis of bis(pentamethylcyclopentadienyl)iron or cobalt complexes.
- Stabilization of organic dianions using these metallocene complexes.
- X-ray crystallography for structural determination.
- Ab initio molecular orbital calculations for electronic structure analysis.
Main Results:
- Successfully stabilized organic dianions using [M(Cp*)2]+ complexes, where M = Fe or Co and Cp* = pentamethylcyclopentadienyl.
- Determined the crystal structure of the 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) dianion within the complex.
- X-ray data indicates a localized, non-aromatic ring structure for the DDQ dianion.
- Computational analysis supports the localized structure, contrasting with a delocalized aromatic model.
Conclusions:
- The [M(Cp*)2]+ complex provides effective stabilization for reactive organic dianions.
- The DDQ dianion adopts a localized structure, confirmed by both experimental and computational methods.
- This work opens avenues for studying other highly reduced organic species.
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