# Lecture 16: VSEPR Structures, Speciality of Boron

### Structures

• When oxygen is connected to central atom, there is a double bond

### Speciality of Boron

• Boron has 8 electrons in the outer most shell, it is an electron deficient molecule
• To form a bond with amonia, which has a lone pair (﻿$Bf_3$﻿ - Lewis Acid, ﻿$NH_3$﻿ - Lewis Base)
• Paramagnetic - Unpaired electrons
• Diamagnetic - Most organic compound because all electrons are paid
• No unpaired electrons
• Bond Order - Number of bonds/number of atoms connected to the central atom
• Related to bond strength
• For bonds between the same 2 atoms, as bond order increases, bond length decreases
• Same 2 atoms
• If different atoms, look at the central atom to find ﻿$BO$﻿ in each bond type
• The bond order will be more than 1 less than 2, same for bond energy