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Solid-state tautomerism in 2-carboxyindan-1,3-dione
Venelin Enchev1, Silvia Angelova, Marin Rogojerov
1Institute of Organic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. venelin@orgchm.bas.bg
The Journal of Physical Chemistry. A
|February 23, 2011
Summary
The solid-state structure of 2-carboxyindan-1,3-dione likely involves two coexisting dimeric forms. These dimers interconvert through an intramolecular proton transfer, with a calculated energy barrier of 5.82 kcal mol(-1).
Area of Science:
- Solid-state chemistry
- Computational chemistry
- Spectroscopy
Background:
- 2-carboxyindan-1,3-dione is a compound whose solid-state structure is not well-defined due to poor solubility.
- Understanding the structural dynamics and tautomerism is crucial for its chemical applications.
Purpose of the Study:
- To elucidate the solid-state structure of 2-carboxyindan-1,3-dione.
- To investigate the tautomeric equilibrium and proton transfer dynamics in the solid state.
Main Methods:
- Quantum-chemical calculations (MP2/6-31++G level)
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy
- Infrared (IR) spectroscopy
Main Results:
- Poor solubility prevented single crystal X-ray diffraction.
- Two dimeric structures, arising from tautomers of 2-carboxyindan-1,3-dione, are proposed to coexist in the solid state.
- The calculated energy barrier for intramolecular proton transfer between tautomeric forms is 5.82 kcal mol(-1).
Conclusions:
- The solid-state structure of 2-carboxyindan-1,3-dione is characterized by coexisting dimeric tautomers.
- Intramolecular proton transfer facilitates interconversion between these dimeric forms.
- The study provides insights into the structural behavior of 2-carboxyindan-1,3-dione in the solid state using computational and spectroscopic methods.
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