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Updated: Jun 1, 2026
19:58
Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
1-Bromo-4-chloro-2,5-dimethoxy-benzene
Summary
This study reveals a disordered halogen site in a novel compound (C(8)H(8)BrClO(2)), where bromine and chlorine atoms occupy each site equally. The molecular structure features equivalent methoxy groups due to crystallographic inversion.
Area of Science:
- Crystallography
- Organic Chemistry
- Molecular Structure Analysis
Background:
- Understanding molecular symmetry and disorder is crucial in crystal structure determination.
- Halogen site disorder can significantly impact a molecule's properties and reactivity.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, C(8)H(8)BrClO(2).
- To investigate the implications of crystallographic symmetry on molecular arrangement and atom site occupancy.
Main Methods:
- Single-crystal X-ray diffraction analysis was employed to determine the molecular structure.
- Crystallographic symmetry operations, specifically inversion, were analyzed to explain observed disorder.
Main Results:
- The molecule C(8)H(8)BrClO(2) crystallizes with the molecule situated on a crystallographic inversion center.
- This inversion center leads to a 50% occupancy of both bromine and chlorine at each halogen site, indicating significant halogen disorder.
- The inversion symmetry also renders the two methoxy groups equivalent, with dihedral angles close to planarity with the aromatic ring (8.8(4)°).
Conclusions:
- The crystal structure of C(8)H(8)BrClO(2) exhibits unique halogen disorder driven by crystallographic inversion.
- The findings provide insights into the precise molecular geometry and packing in halogen-substituted aromatic compounds.
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