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Using invariom modelling to distinguish correct and incorrect central atoms in `duplicate structures' with
Claudia M Wandtke1, Matthias Weil2, Jim Simpson3
1Institut für Anorganische Chemie der Universität Göttingen, Tammannstrasse 4, Göttingen D-37077, Germany.
The invariom method with aspherical scattering factors can identify correct coordination compound structures from diffraction data alone. This approach distinguishes between metal ions in duplicate structures when other data are missing.
Area of Science:
- Crystallography
- Inorganic Chemistry
- Computational Chemistry
Background:
- Accurate structural determination of coordination compounds is crucial.
- The invariom method offers advanced modeling capabilities beyond traditional approaches.
- Duplicate structures with different metal ions present identification challenges.
Purpose of the Study:
- To apply the invariom method with aspherical scattering factors to resolve ambiguities in 'duplicate structures'.
- To demonstrate the ability to identify the correct metal ion solely from diffraction data.
- To validate structural assignments using quantum-chemical computations.
Main Methods:
- Utilizing the invariom method with aspherical atomic scattering factors.
- Refining crystal structures against deposited Bragg intensities.
- Performing quantum-chemical computations on refined models.
Main Results:
- The invariom method successfully identified the correct metal ion in duplicate structures.
- Aspherical scattering factors enabled structural identification without external spectroscopic data.
- Ligand environment modeling was often sufficient for element assignment.
Conclusions:
- The invariom method with aspherical scattering factors is a powerful tool for resolving structural ambiguities in coordination compounds.
- This method surpasses the limitations of the independent atom model for such cases.
- Computational chemistry validates the structural assignments made through crystallographic refinement.
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