Study Guide
,Stereochemistry - Thinking in 3D
What is Chirality?
In a way, molecules are kind of like our hands. Just how we have a left and right hand,
molecules exist in these left and right-handed versions of themselves. We refer to the
“handedness” of a molecule as its chirality.
Chirality is how we view
substituents around a
central atom; it considers the
3D arrangements of
molecules around points that
lack symmetry
Chirality can be further broken down into two points of interest:
1) Asymmetric Centers
2) Stereocenters
A molecule is said to contain an asymmetric center if it satisfies the following conditions:
- Has a tetrahedral molecular geometry (sp3 hybridized)
- Has 4 unique substituents
, - Can exist in different 3D arrangements but have the same physical
structure
A stereocenter is a bit of a broader category for
molecules. These include:
- Asymmetric Centers
- Cis-Trans isomerism
Both molecules are but-2-ene but have different
spatial arrangements as indicated by the cis/trans
naming.
Not all molecules have chiral centers. When a molecule lacks chirality, or in other words
has a plane of symmetry, we describe it as an “achiral” molecule. For now, let’s focus on
exploring ways we can visualize and study chirality.
,Stereochemistry - Thinking in 3D
What is Chirality?
In a way, molecules are kind of like our hands. Just how we have a left and right hand,
molecules exist in these left and right-handed versions of themselves. We refer to the
“handedness” of a molecule as its chirality.
Chirality is how we view
substituents around a
central atom; it considers the
3D arrangements of
molecules around points that
lack symmetry
Chirality can be further broken down into two points of interest:
1) Asymmetric Centers
2) Stereocenters
A molecule is said to contain an asymmetric center if it satisfies the following conditions:
- Has a tetrahedral molecular geometry (sp3 hybridized)
- Has 4 unique substituents
, - Can exist in different 3D arrangements but have the same physical
structure
A stereocenter is a bit of a broader category for
molecules. These include:
- Asymmetric Centers
- Cis-Trans isomerism
Both molecules are but-2-ene but have different
spatial arrangements as indicated by the cis/trans
naming.
Not all molecules have chiral centers. When a molecule lacks chirality, or in other words
has a plane of symmetry, we describe it as an “achiral” molecule. For now, let’s focus on
exploring ways we can visualize and study chirality.
