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Updated: Feb 6, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
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Stereoisomerism in Lanthanide Complexes: Enumeration, Chirality, Identification, Random Coordination Ratios
Frederico T Silva1, Sóstenes L S Lins2, Alfredo M Simas1
1Departamento de Química Fundamental, CCEN , Universidade Federal de Pernambuco , 50740-560 Recife , Pernambuco , Brazil.
Inorganic Chemistry
|August 14, 2018
Summary
This study introduces random coordination ratios (RCRs) to quantify lanthanide complex stereoisomers. A new method uniquely identifies stereoisomers and their absolute configurations, revealing overlooked chirality in these compounds.
Area of Science:
- Coordination Chemistry
- Stereochemistry
- Lanthanide Complexes
Background:
- Coordination chirality in lanthanide complexes is often overlooked.
- These complexes can exhibit high dissymmetry factors when luminescent.
- A systematic method for stereoisomer identification is needed.
Purpose of the Study:
- Introduce random coordination ratios (RCRs) for lanthanide complexes.
- Develop a method for unambiguous stereoisomer identification and absolute configuration determination.
- Classify and enumerate stereoisomers for various coordination numbers and ligand types.
Main Methods:
- Enumeration of all possible stereoisomers for lanthanide complexes (coordination numbers 4-9).
- Application of Pólya's theorem to confirm stereoisomer counts.
- Classification of stereoisomers by symmetry point groups and generation of Cartesian coordinates.
Main Results:
- A novel concept of random coordination ratios (RCRs) is presented.
- A method for unique stereoisomer identification and unambiguous stereochemistry characterization is established.
- A dilanthanide complex was identified as a meso compound, highlighting the method's utility.
Conclusions:
- The developed methodology provides a robust framework for analyzing lanthanide complex stereochemistry.
- This work facilitates the recognition of coordination chirality and the identification of meso compounds.
- The generated stereoisomer geometries serve as valuable starting points for theoretical calculations.
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