Enantiomeric excess percentage (aka optical purity percentage) calculations are one of the few equations you’ll come across in your orgo course. This video gives you a step by step breakdown and practice examples. You’ll see how to find the percent excess via logic and see the numbers side by side. (Watch on YouTube: Optics 3. Click […]

## Enantiomeric Excess Percent Optical Purity Calculations and Logic

## Polarimetry in Optical Activity

Polarimetry is the key to understanding chiral molecules in terms of optical activity. This video goes behind the scenes of the polarimeter to help you understand what plane polarized light has to do with chiral molecules. Part 1 (of 3) in this mini series explains + D and – L, dextrorotatory and levorotatory, and their (lack […]

## Swap Method for finding R and S Configurations Chirality

Chirality/Stereochemistry Video Series: Video 4 R and S configurations are pretty straight-forward when priority group #4 is conveniently in the back of the molecule. There’s even a quick trick for when group #4 is forward (as taught in this video). But what happens when priority group #4 is in the plain of the page? Do […]

## Finding R and S When Group 4 is Forward

Chirality/Stereochemistry Video Series: Video 3 This video shows you why and how to reverse R and S when group #4 is forward to help you quickly and easily master relative configurations when studying chirality and stereochemistry. (Watch on YouTube: Group 4. Click cc on bottom right for video transcription.) <– Watch Previous Video: R and […]

## Fischer Projection R and S Stereochemistry Trick

Chirality/Stereochemistry Video Series: Video 6 Fischer projections provide a simple 2-dimensional representation for complex 3-dimensional structures. Which is great for drawing complex molecules, but not so much fun if asked to determine R and S configurations. Many books and professors will have you redraw the Fischer projection into a 3-dimensional sawhorse or skeletal structure. I […]

## R and S configuration for Lengthy Complex Substituents

Chirality/Stereochemistry Video Series: Video 5 R and S configurations are found by ranking substituents on a chiral carbon. This is relatively straight-forward when substituents contain 1-3 atoms. This gets more confusing when the substituents are long, complex, and contain many of the same atoms. This orgo tutorial video shows you how to approach lengthy and […]

## Newman Projection Stereochemistry R & S Trick

Chirality/Stereochemistry Video Series: Video 7 Finding R and S configurations for non-traditional molecules can be somewhat tricky. This video teaches you how to quickly find configurations of molecules presented in a Newman Projection. Learn how to view the molecule and quickly assign priority WITHOUT the need to redraw into a sawhorse projection. (Watch on YouTube: […]

## R and S Configuration using Cahn Ingold Prelog Priority Rules

Chirality/Stereochemistry Video Series: Video 2 Chiral carbons are identified as having 4 unique substituents. Finding the Absolute Configuration – R and S comes as a result of ranking and order substituents, specifically by noting the configuration of the top 3 groups. This video shows you how to prioritize substituents to find R and S configurations […]

## Introduction to Stereochemistry Enantiomers and Chiral Molecules

Chirality/Stereochemistry Video Series: Video 1 Chirality is an exciting but potentially tricky topic in organic chemistry. Why? because it’s tough to visualize 2-dimensional drawings as a 3-dimensional structure. But don’t be like the thousands of students struggling with this topic. My chirality series will take you through this topic step by step to ensure that […]