How to Determine Absolute Configuration Using Circular Dichroism
Absolute configuration is a way to describe the stereochemistry of molecules, defined based on the spatial arrangement of stereoisomers. It classifies based on the actual three-dimensional distribution of the structure, independent of optical activity or flocculation activity. The most commonly used method of description is the Cahn-Ingold-Prelog (CIP) rules. In spectroscopy, Circular Dichroism (CD) is a powerful tool used to study the structure and configuration of molecules, particularly biological macromolecules. CD spectra depend on the differential absorption of left and right circularly polarized light by the molecules.
The following explains how to use Circular Dichroism to determine the absolute configuration of molecules:
1. Record the Circular Dichroism Spectrum
First, you need to perform Circular Dichroism analysis on your sample. During this process, you will record the difference in absorption of left and right circularly polarized light by the sample.
2. Analyze the Circular Dichroism Spectrum
Next, you need to analyze your CD spectrum. This includes identifying the major absorption bands and their intensities, which can provide information about the sample's structure.
3. Compare with Spectra of Known Configurations
Then, you need to compare your sample's CD spectrum with the CD spectra of samples with known configurations. This can often be achieved by looking up the relevant information in the literature. You need to find molecules with structures similar to your sample and examine their CD spectra.
4. Determine Absolute Configuration
Finally, you can determine the absolute configuration of your sample based on the similarity between its CD spectrum and those of samples with known configurations. If your sample's CD spectrum is similar to that of a sample with a known R configuration, your sample may have an R configuration. Similarly, if it matches a sample with a known S configuration, it may have an S configuration.
Please note that this method does not provide absolute certainty, as CD spectra can be influenced by various factors including solvent effects, sample concentration, and temperature. Nevertheless, it remains a very useful tool and can provide strong evidence for determining the absolute configuration of molecules. These are the steps to determine the absolute configuration of molecules using Circular Dichroism.
Biotapeck Biotechnology - A premium service provider for bioproduct characterization and multi-omics mass spectrometry analysis.
Related services:
Protein Circular Dichroism Analysis
How to order?
