Name: Chirality: Chiral and Achiral Molecules
Uploaded: 2023-04-30T18:28:33
Description: Learn by watching this video about Chirality: Chiral and Achiral Molecules at JoVE.com

Chirality refers to a special type of asymmetry whereby an object and its mirror image are not identical. For example, our left hand possesses chirality, as its mirror image, the right hand, is not superposable on the left hand.
Such objects are classified as chiral, as they possess the property of chirality. Achiral objects, such as a mug and its mirror image, can be superposed on each other.
For example, 2-butanol is chiral, as the mirror image of 2-butanol is not superposable on the molecule. In contrast, ethanol is achiral, as the mirror image of ethanol is the same as the molecule.
Here, 2-butanol has a tetrahedral carbon atom with four different groups attached to it, referred to as a chiral center. Molecules with only one chiral center are always chiral.
In general, chiral objects are identified by the asymmetry in their structure. An object or a molecule is usually chiral if it lacks both a plane of symmetry and a center of symmetry.
A plane of symmetry is an imaginary plane that divides the object into two equivalent parts, each of which is a mirror image of the other. For example, the achiral ethanol molecule has a plane of symmetry passing through the methyl and hydroxyl groups.
A center of symmetry is a point located in the object such that any two lines from this point in opposite directions contact identical components at equal distances. For example, the achiral molecule trans-2-butene has a center of symmetry located at the center of the &#960; bond.
While the cis isomer of 1,3-dimethylcyclohexane has a plane of symmetry, the trans isomer lacks both a plane of symmetry and a center of symmetry. Accordingly, the cis isomer is achiral and the trans isomer is chiral.
Compounds such as 2,3-pentadiene lack a plane of symmetry and a center of symmetry due to hindered rotation around the &#960; bond; as such, 2,3-pentadiene is chiral.

chirality

Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects &#8212; objects that have superposable mirror images &#8212; do not have a sense of handedness. For example, socks are achiral; as such, a sock can be worn on both feet equally well.
Chiral objects are identified by the lack of certain symmetry elements in their structure. Specifically, chiral objects lack a plane of symmetry: an imaginary plane that can divide an object into two equal halves. In addition, chiral objects also lack a center of symmetry: a point from which similar components of the object are equidistant and opposite to each other.
Chiral molecules exist as a pair of non-superposable mirror images. As a rule of thumb, molecules which have only one tetrahedral carbon atom with four different substituents attached to it are always chiral. Such a tetrahedral carbon atom is referred to as a chiral center. In general, to identify whether a molecule is chiral, the molecular geometry should be known. If the molecular geometry lacks a plane of symmetry as well as a center of symmetry, the molecule is chiral.

Learn by watching this video about Chirality: Chiral and Achiral Molecules at JoVE.com

Chirality: Chiral and Achiral Molecules

Chirality

Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. ...