In order to better visualize different conformations of a molecule, it is convenient to use a drawing convention called the Newman projection. In a Newman projection, we look lengthwise down a specific bond of interest – in this case, the carbon-carbon bond in ethane. We depict the ‘front’ atom as a dot, and the ‘back’ atom as a larger circle.

2020年2月28日 · In this article: introducing conformational isomers, staggered and eclipsed conformations, the Newman projection, the dihedral angle (torsion angle), and the rotational barrier to ethane (torsional strain)!

Ethane (C 2 H 6) is the simplest alkane, consisting of two carbon atoms bonded by a single sigma bond and surrounded by hydrogen atoms. It is an excellent starting point to grasp the concept of Newman projection. Ethane exists in two primary conformations: the staggered conformation and the eclipsed conformation.

Newman projection formula for different conformations of ethane: When an ethane molecule rotates about its carbon – Carbon single bond, two extreme conformations can result in the staggered conformation and the eclipsed conformation.

In order to better visualize these different conformations, it is convenient to use a drawing convention called the Newman projection. In a Newman projection, we look lengthwise down a specific bond of interest – in this case, the carbon-carbon bond in ethane. We depict the ‘front’ atom as a dot, and the ‘back’ atom as a larger circle.

Interactive 3D animations of ethane conformations and Newman projections for students studying University chemistry courses

Newman Projections of Ethane. For open-chain molecules like ethane, Newman projections serve as useful tools for visualizing conformations. In the case of ethane, the front carbon atom will have three hydrogens situated around it, and the back carbon atom will similarly be surrounded by three hydrogens.

Draw Newman projections of these conformers and explain this curious result. Newman projections for the staggered and eclipsed conformations of ethane are shown below. Figure 4.6 illustrates the Newman projections for both the staggered and eclipsed conformations for ethane.

Newman projections are utilized as a method to draw complex alkane molecules in the perspective of front to back. They allow for a 3-dimensional drawing indicating order and depth and can be useful for stereochemistry.

But before we go into the nitty-gritty details of the conformations of the more complex molecules, let’s look at something very simple. The simplest molecule with a C-C single bond is ethane. Here are a couple of ways how we can represent ethane: The two orientations of the CH 3 group give us the two different orientations of ethane in space ...