The next MO has a node in the center of the molecule. &&?8 This is a classic diene MO,with bonding between C1-C2,and C3-C4. There is an antibonding interaction between C2-C3. This MO has two bonding and one antibonding interactions-so we expect it to be overall bonding,but higher in energy than 1. The third MO has two nodes. &?98 With two antibonding and one bonding interaction,overall this is an antibonding MO,and is denoted by an asterix (*) The fourth MO has 3 nodes,and is completely antibonding &9t9 元4 This is the highest energy MO. Ch15 Conjugated Systems (landscape) Page 7 Ch15 Conjugated Systems (landscape) Page 7 The next MO has a node in the center of the molecule. This is a classic diene MO, with bonding between C1-C2, and C3-C4. There is an antibonding interaction between C2-C3. This MO has two bonding and one antibonding interactions – so we expect it to be overall bonding, but higher in energy than 1. The third MO has two nodes. With two antibonding and one bonding interaction, overall this is an antibonding MO, and is denoted by an asterix (*). The fourth MO has 3 nodes, and is completely antibonding. This is the highest energy MO. 2 3 * 4 *