CEM 141 Lecture Notes - Lecture 26: Orbital Hybridisation, Antibonding Molecular Orbital, Sigma Bond
Document Summary
Carbon comes in many different forms (allotropes) 2 of them, diamond and graphite is what we"ll be talking about. Each carbon forms 4 bonds to 4 identical carbons. The bonds arrange themselves towards the corners of a 4 sided figure (a tetrahedron). The c-c-c bond angle is ~109 (diamonds don"t melt, they would decompose) To explain bonding in carbon we need to use a different model of bonding: In this model we assume that the atomic orbitals overlap to form bonds. These bonds are often shown as sticks. We consider the bonds to be localized between 2 bonded atoms (not like in molecular orbital theory) Atomic orbitals combine to form an equal number of molecular orbitals. Each orbital can contain up to two electrons. Electrons in bonding orbitals stabilize the system. Electrons in anti-bonding orbital make it less stable. Atomic orbitals overlap to form a bond. The greater the overlap, the stronger the bond.
