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5-Iodouracil: structure of a reflection twin
Martin Lutz1, Thomas J S de Klein1, Jeroen Huijben1
1Bijvoet Center for Biomolecular Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Acta Crystallographica. Section C, Structural Chemistry
|October 1, 2015
Summary
The crystal structure of 5-iodouracil was determined using X-ray diffraction. Twinning in the crystal was attributed to stacking faults in its two-dimensional packing.
Area of Science:
- Crystallography
- Solid-state chemistry
- Molecular structure determination
Background:
- 5-iodouracil is a halogenated derivative of uracil, a fundamental component of nucleic acids.
- Understanding the crystal structure of modified nucleobases is crucial for fields like medicinal chemistry and materials science.
- Crystal twinning can complicate structure determination and provide insights into crystal growth mechanisms.
Purpose of the Study:
- To determine the precise three-dimensional crystal structure of 5-iodouracil.
- To investigate the nature of twinning in 5-iodouracil crystals.
- To elucidate the relationship between molecular packing and observed twinning.
Main Methods:
- Single-crystal X-ray diffraction analysis.
- Noncentrosymmetric space group determination (P21).
- Analysis of merohedral twinning and twin element (mirror plane perpendicular to c*).
Main Results:
- The crystal structure of 5-iodouracil (C4H3IN2O2) was successfully determined.
- The crystal exhibited nonmerohedral twinning with enantiomorphically pure twin components.
- Stacking faults within the two-dimensional molecular packing were identified as the likely cause of the observed twinning.
Conclusions:
- The determined crystal structure provides a detailed understanding of 5-iodouracil's molecular arrangement.
- Stacking faults are confirmed as a significant factor contributing to crystal twinning in this system.
- This study offers insights into crystal growth defects and their impact on crystallographic analysis.
Keywords:
5-iodouracilcrystal structureenantiomorphic puritynonmerohedrally twinned crystalstacking faultsMore Related Videos
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