1. What is the Fraction of Major Isomer Calculator?

Definition: This calculator determines the mole fraction of the major enantiomer (R) based on the percent enantiomeric excess (%ee).

Purpose: It helps chemists and researchers quantify the purity of chiral compounds and determine the ratio of enantiomers in a mixture.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( FR \) — Mole fraction of the R enantiomer (%)
• \( \%ee \) — Percent enantiomeric excess (0-100%)

Explanation: The formula converts enantiomeric excess into the actual percentage composition of the major isomer.

3. Importance of Enantiomeric Composition

Details: Knowing the exact composition of chiral compounds is crucial in pharmaceuticals, as different enantiomers can have different biological activities.

4. Using the Calculator

Tips: Enter the percent enantiomeric excess (0-100%). The result shows the mole fraction of the major (R) enantiomer.

5. Frequently Asked Questions (FAQ)

Q1: What does 100% ee mean?
A: 100% ee means the sample contains only one enantiomer (pure R or pure S).

Q2: What does 0% ee mean?
A: 0% ee means a racemic mixture (50% R and 50% S).

Q3: How is %ee determined experimentally?
A: Typically measured using polarimetry, chiral chromatography, or NMR with chiral shift reagents.

Q4: What's the relationship between %ee and optical purity?
A: %ee is equivalent to optical purity for pure enantiomers.

Q5: Can this calculator be used for diastereomers?
A: No, this formula is specific for enantiomeric pairs. Diastereomers require different analysis methods.