Automated oxidation-state assignment for metal sites in coordination complexes in the Cambridge Structural Database
Matthew G Reeves1, Peter A Wood2, Simon Parsons1
1Centre for Science at Extreme Conditions and EaStCHEM School of Chemistry, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3FJ, UK.
Summary
An automated workflow accurately assigns oxidation states for transition-metal coordination complexes in the Cambridge Structural Database (CSD). This computational approach enhances data curation efficiency, overcoming limitations of manual methods.
Area of Science:
- Inorganic Chemistry
- Materials Science
- Computational Chemistry
Background:
- The Cambridge Structural Database (CSD) contains over 400,000 transition-metal entries, but many lack curated oxidation-state information.
- Manual curation of remaining entries is impractical due to the vast dataset size and resource intensity.
Purpose of the Study:
- To develop and validate a reliable automated workflow for assigning oxidation states in transition-metal coordination complexes within the CSD.
- To improve the efficiency and accuracy of chemical data curation for inorganic compounds.
Main Methods:
- Implementation of a workflow using CSD Python API scripts for automated oxidation-state assignment.
- Utilizing the bond-valence sum (BVS) method alongside three complementary techniques to enhance assignment confidence.
- Assessing the workflow's performance on a large dataset of unique metal atoms.
Main Results:
- The automated workflow successfully assigned oxidation states in 86% of tested unique metal atoms (47,072 out of 54,999).
- High consensus between multiple methodologies led to successful assignments in 99% of applicable cases.
- The developed procedure overcomes limitations of the BVS method, broadening automated applicability.
Conclusions:
- The presented automated workflow provides a highly reliable method for oxidation-state assignment in transition-metal complexes.
- This computational approach significantly enhances the curation of crystallographic data in the CSD.
- The study demonstrates the power of combining multiple computational methods for accurate chemical property determination.
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