Chapter 14, Problem 19P

Interpretation Introduction

Interpretation:

The orbital diagrams of the given compounds have to be drawn using the polygon and circle method.

Concept introduction:

Polygon and circle method is used to draw the relative energies of the molecular orbitals of conjugated monocyclic system.

In this representation, one corner of the polygon is placed at the bottom, and a circle is drawn touching the corners of the polygon. Horizontal lines are drawn corresponding to the corners of the polygon touching the circle anda dashed horizontal line is drawn at the centre of the polygon.

Bonding molecular orbitals are positioned below the central line of polygon and antibonding molecular orbitals are placed above the line. The nonbonding orbitals are placed at the same level.

Electrons are placed in these orbitals starting from lowest energy level. Cyclopropene is a cyclic compound having three sides with molecular formula ${\text{C}}_{\text{3}}{\text{H}}_{\text{4}}$.

The cyclopropene cation contains two pi electrons.

In cyclopropene anion, there are four electrons.