91影视

1,3-Pentadiene has 鈥渢wo conjugated pie bonds,鈥� so it has four p atomic orbitals. Four atomic orbitals combine to produce four molecular orbitals :${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2\mathbf{,}{\mathbf{蠄}}_3\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_4$

Half are bonding Molecular orbital (${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2$), and the other Half are antibonding molecular orbital (${\mathbf{蠄}}_3\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_4$).

The molecular orbital description for 1,3-pentadiene is drawn as follows:

Molecular orbitals of1,3-pentadiene

1,4-Pentadiene has four electrons (pie electrons). However, unlike the delocalized electrons in 1,3-butadiene, the electrons in 1,4-pentadiene are entirely separate. In other words, the electrons are localized. The molecular orbitals of 1,4-pentadiene have the same energy as ethene(a compound with one pair of localized electrons).

The molecular orbital description of 1,4-pentadiene has two p atomic orbitals that produce two molecular orbitals. The in-phase interaction of the two p atomic orbitals forms a $\mathbf{蟺}$bonding MO, designated by ${\mathbf{蠄}}_1$, and the out-of-phase interaction forms an ${\mathbf{蟺}}^{*}$antibonding MO, designated by ${\mathbf{蠄}}_2$drawn as follows:

Molecular orbitals of1,4-Pentadiene

1,3,5-heptatriene has 鈥渢hree conjugated pie bonds鈥� with six p atomic orbitals. six atomic orbitals combine to produce six molecular orbitals :${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2\mathbf{,}{\mathbf{蠄}}_3\mathbf{,}{\mathbf{蠄}}_4\mathbf{,}{\mathbf{蠄}}_5\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_6$

Half are bonding Molecular orbital (${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2\mathbf{,}{\mathbf{蠄}}_3$), and the other Half are antibonding molecular orbital (${\mathbf{蠄}}_4{\mathbf{蠄}}_5\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_6$).

The molecular orbital description for 1,3,5-heptatriene is drawn as follows:

Molecular orbitals of1,3,5-heptatriene

1,3,5,8-nonatetraene has 鈥渢hree conjugated pie鈥� and 鈥渙ne 鈥渋solated pie鈥� bonds.

Three conjugated double bonds have a molecular orbital description with six p atomic orbitals. Six atomic orbitals combine to produce six molecular orbitals:${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2\mathbf{,}{\mathbf{蠄}}_3\mathbf{,}{\mathbf{蠄}}_4\mathbf{,}{\mathbf{蠄}}_5\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_6$ , Half are bonding Molecular orbitals (${\mathbf{蠄}}_1\mathbf{,}{\mathbf{蠄}}_2\mathbf{,}{\mathbf{蠄}}_3$), and the other Half is antibonding molecular orbitals (${\mathbf{蠄}}_4{\mathbf{蠄}}_5\text{鈥�}\mathbf{and}\text{鈥�}{\mathbf{蠄}}_6$).

The molecular orbital description ofThree conjugated double of 1,3,5,8-nonatetraene is drawn as follows:

Molecular orbitals ofthree conjugated double of 1,3,5,8-nonatetraene

The molecular orbital description isolated pie bond of 1,3,5,8-nonatetraene has two p atomic orbitals that produce two molecular orbitals. The in-phase interaction of the two p atomic orbitals forms a bonding $\mathbf{蟺}$MO, designated by ${\mathbf{蠄}}_1$, and the out-of-phase interaction forms an${\mathbf{蟺}}^{*}$ antibonding MO, designated by ${\mathbf{蠄}}_2$ drawn as follows:

Molecular orbital of isolated pie bond of 1,3,5,8-nonatetraenem