Identify the chirality centers in the following molecules (green =Cl, yellow-green =F ):

Name: Problem 4, Chapter 5: Organic Chemistry
Uploaded: 2020-05-14T04:20:19-08:00
Duration: 2 min 59 s
Channel: Bobby Barnes
Description: Identify the chirality centers in the following molecules (green =Cl, yellow-green =F ):

Identify the chirality centers in the following molecules...

Key Concepts

Chirality Center

A chirality center (often called a stereocenter) is an atom—most commonly a carbon atom—with four different substituents arranged in space such that its mirror image is non-superimposable. This spatial arrangement leads to molecules that exhibit optical isomerism, meaning they can rotate plane-polarized light differently. The presence of a chirality center is a primary factor in determining the stereochemical properties of a molecule.

Stereochemistry

Stereochemistry is the branch of chemistry that deals with the three-dimensional arrangement of atoms in molecules. It examines how the spatial orientation of atoms influences the physical and chemical properties of substances. This field is critical when analyzing chirality because it provides the framework for categorizing and predicting the behavior of stereoisomers, including enantiomers and diastereomers.

Substituents

Substituents refer to the atoms or groups attached to a central atom in a molecule. For a center to be chiral, the substituents attached must all be different, which disrupts any potential symmetry at that atom. The nature and arrangement of these substituents are crucial for determining the configuration at the chirality center and the overall stereochemical characteristics of the molecule.

Molecular Symmetry

Molecular symmetry involves the study of the balance and equivalence of parts within a molecule. A molecule that has certain symmetry elements, such as a mirror plane or a center of inversion, may not be chiral even if it contains stereocenters. Evaluating the symmetry of a molecule can help determine whether a potential chirality center is valid, as true chirality centers lead to non-superimposable mirror images.

Transcript

00:01 They want us to identify chiral centers in each of these molecules here.

00:06 So how about this first one? so a quick way to do this is to just look to see if you have four different groups attached to one of these carbons.

00:17 So like this oxygen only has two, so can't this carbon here has two hydrogen so it can't be one.

00:24 This carbon here, so maybe i should like do those stars on the side.

00:30 So let me get rid of these.

00:31 So like this one right here, notice how it has an oxygen attached, a hydrogen, and two carbons.

00:40 But now, if we were to compare these two carbons, notice that this carbon here has two hydrogens attached to it.

00:49 But this carbon here has only one hydrogen.

00:52 So these would be two different groups going left and right.

00:55 So this chiral, i mean, this carbon here would actually be a chiral center.

00:59 Now we can go one more over, and then see if this is.

01:05 So it has an oxygen attached, a hydrogen, and then two carbons.

01:09 So now notice the carbon on the right is double bonded to an oxygen, and the one on the left is just single bonded to an oxygen.

01:15 So those two carbon groups would be different as well.

01:17 So this would be a chiral center.

01:21 And now this last carbon right here doesn't have four different groups attached.

01:29 It's sp2, and normally, anytime anything is planar, it's not going to be chiral...

Please give Ace some feedback