We've previously explored the shapes of molecules with 2, 3, or 4 electron domains. Let’s now dive into the fascinating universe of molecules with expanded octets - 5 or 6 electron domains!

Imagine placing 5 dots around you. What's the best way to ensure they're as far from each other as possible? The answer: make a star! 🌟

✨ Basics

• Name of Geometry: Trigonal Bipyramidal.
• Electron Domains: 5.
• Bond Angles: 120° and 90°.

✨ Details

• The shape is like two pyramids (think of the Egyptian pyramids) that share the same base.
• Electron domains split into:
  • Equatorial: Form the triangular base, 120° apart.
  • Axial: Form the "poles" of the molecule, 90° from the base.

• All bonding? ➔ Trigonal Bipyramidal!
• Four bonding, one non-bonding? ➔ Rock the Seesaw!
• Three bonding, two non-bonding? ➔ T-shaped like a T-shirt!
• Two bonding, three non-bonding? ➔ Keep it Linear!

⚠️ Fact Alert: Non-bonding pairs can be party crashers. They repel more and can distort our 120° and 90° angles.

Think of a dice! If you add an electron domain on the top and bottom, you'll get the octahedral shape!

✨ Basics

• Name of Geometry: Octahedral.
• Electron Domains: 6.
• Bond Angles: A perfect 90° everywhere.

✨ Details

• Imagine an 8-sided 3D object where each face is a triangle. That's an octahedron!
• No need to worry about axial or equatorial here; everyone's 90° to each other.