Ethane Molecule Representation

Molecular Representation

• Two common representations:
  • 2D drawing: Lacks 3D spatial information.
  • Wedge and Dash drawing: Provides 3D spatial information.
    • Wedge: Bond coming out towards the viewer.
    • Dash: Bond going away from the viewer.
    • Straight line: Bond in the plane of the page.

Conformations of Ethane

• Conformations: Different arrangements of atoms due to bond rotation.
• Carbon-Carbon Single Bond:
  • Allows free rotation, leading to different conformations.

Staggered Conformation

• One of the possible conformations of ethane.
• Representation Views:
  • Wedge and Dash: Helps in visualizing the arrangement.
  • Sawhorse: Another way to view the staggered conformation.
  • Newman Projection: Looking down the carbon-carbon bond.
    • Green hydrogens (front carbon) and white hydrogens (back carbon).
    • Dihedral/Torsional Angle: 60 degrees, hydrogens are staggered.

Eclipsed Conformation

• Another important conformation.
• Hydrogens:
  • Green hydrogens are in front of (eclipsing) the white hydrogens.
• Representation Views:
  • Sawhorse: Visualization with stretched bonds.
  • Wedge and Dash: Visualizes the plane and spatial orientation.
  • Newman Projection: Staring directly down the carbon-carbon bond.
    • Dihedral/Torsional Angle: 0 degrees, hydrogens are eclipsing.

Key Concepts

• Dihedral/Torsional Angle: Angle between bonds.

  • Important in defining staggered (60 degrees) and eclipsed (0 degrees) conformations.

• Model Projection: Viewing ethane using a model set can help visualize rotations and conformations effectively.