Chemical Bonding: Resonance and Orbitals

This lecture explores the concept of resonance in chemical bonding, focusing on the comparison between Lewis structures and molecular orbitals. The instructor discusses the importance of resonance structures in understanding molecule properties, particularly acidity. The lecture delves into the energy split in sigma and pi bonds, the significance of HOMO and LUMO orbitals, and the selection of orbitals for interactions. Additionally, the interaction between different orbitals is illustrated through energy diagrams. Exceptions to the VSEPR-hybridization rule are explained, emphasizing the role of p orbitals in interacting with pi systems. The session concludes with an analysis of molecular hybridization and orbital interactions, providing insights into the exceptional cases where resonance plays a crucial role.