Which of these molecular fragments would you expect to be more likely to give rise to electrical conductivity? Explain your reasoning. (a)

(b)

Verified step by step guidance

1. Identify the key difference between the two molecular fragments: Fragment I has single bonds only, while Fragment II has alternating single and double bonds (conjugated system).
2. Recall that electrical conductivity in molecular structures is often associated with the presence of delocalized electrons.
3. Understand that delocalized electrons can move freely across the molecule, which is facilitated by the conjugated system in Fragment II.
4. Recognize that the conjugated system in Fragment II allows for the overlap of p-orbitals, creating a 'pi cloud' where electrons can move more freely.
5. Conclude that Fragment II is more likely to give rise to electrical conductivity due to the presence of delocalized electrons in the conjugated system.

Key Concepts

Electrical Conductivity

Electrical conductivity refers to the ability of a material to conduct electric current. This property is influenced by the presence of free-moving charged particles, such as electrons or ions. In molecular structures, the arrangement and type of atoms can determine how easily these charged particles can move, thus affecting conductivity.

Molecular Structure and Bonding

The molecular structure and bonding of a compound significantly influence its physical properties, including conductivity. Structures with delocalized electrons, such as those found in conjugated systems or metals, typically exhibit higher conductivity. The arrangement of atoms in the provided diagrams may indicate the potential for electron mobility, which is crucial for conductivity.

Crystalline vs. Amorphous Structures

Crystalline structures have a well-defined, ordered arrangement of atoms, which can facilitate the movement of electrons, enhancing conductivity. In contrast, amorphous structures lack this order, potentially hindering electron flow. The diagrams depict two different arrangements, and understanding their crystalline nature can help predict their electrical properties.