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Published on: January 19, 2016
A new polymorph of 2,6-dimeth-oxy-benzoic acid
1Chemistry Department, "Sapienza" University of Rome, P.le A. Moro, 5, I-00185 Rome, Italy.
Acta Crystallographica. Section E, Structure Reports Online
|December 27, 2011
Summary
A new tetragonal crystalline form of 2,6-dimethoxybenzoic acid was identified. Unlike the known orthorhombic form, this polymorph features dimeric units stabilized by hydrogen bonds between carboxyl groups.
Area of Science:
- Crystallography
- Solid-state chemistry
- Organic chemistry
Background:
- Polymorphism is crucial in determining the physical and chemical properties of organic compounds.
- 2,6-dimethoxybenzoic acid exists in known crystalline forms with distinct hydrogen bonding patterns.
- Co-crystal screening is a method for discovering new crystalline forms.
Purpose of the Study:
- To identify and characterize new crystalline forms of 2,6-dimethoxybenzoic acid.
- To investigate the structural differences and hydrogen bonding in a novel polymorph.
Main Methods:
- X-ray diffraction analysis was used to determine the crystal structure.
- Structural comparison with previously reported forms was performed.
- Analysis of molecular conformation and hydrogen bonding interactions.
Main Results:
- A new tetragonal crystalline form of 2,6-dimethoxybenzoic acid was discovered.
- The molecule exhibits a non-planar conformation with the carboxyl group twisted by 65.72°.
- The carboxyl group is disordered, and molecules form dimeric units via O-H⋯O hydrogen bonds.
Conclusions:
- The new tetragonal polymorph exhibits unique structural features compared to the orthorhombic form.
- Hydrogen bonding in the tetragonal form leads to the formation of molecular dimers.
- This discovery expands the understanding of 2,6-dimethoxybenzoic acid's solid-state behavior.
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