Question

Draw a structural formula for each compound. (a) 1-Nitronaphthalene (b) 1,6 -Dichloronaphthalene (c) 9-Bromoanthracene (d) 2-Methylphenanthrene

Short answer

Question: Draw the structural formula for 1,6-Dichloronaphthalene. Answer: 1,6-Dichloronaphthalene consists of a naphthalene parent structure with two chloro (-Cl) groups at carbon atom 1 and carbon atom 6. The structural formula for 1,6-Dichloronaphthalene is: 

Step-by-step solution

Identify the parent structure

For each compound, we need to identify the base skeleton, also called the parent structure, before adding substituents. The parent structures are: (a) Naphthalene: a fused-ring system with two benzene rings (10 carbon atoms in total) (b) Naphthalene: same as (a) (c) Anthracene: a fused-ring system with three benzene rings (14 carbon atoms) (d) Phenanthrene: a fused-ring system with three benzene rings, similar to anthracene but with a different arrangement of double bonds.

Determine the position of substituents

Now that we have identified the parent structures, we need to add the substituents in the correct positions as indicated by the compound names: (a) 1-Nitronaphthalene: has a nitro (-NO2) group at the first carbon atom of the naphthalene structure. (b) 1,6-Dichloronaphthalene: has two chloro (-Cl) groups at carbon atom 1 and carbon atom 6 of the naphthalene structure. (c) 9-Bromoanthracene: has a bromo (-Br) group at the ninth carbon atom of the anthracene structure. (d) 2-Methylphenanthrene: has a methyl (-CH3) group at the second carbon atom of the phenanthrene structure.

Draw the structural formulas

Finally, we will draw the structural formulas for each compound, showing the parent structures with their substituents in the correct positions. (a) 1-Nitronaphthalene:  (b) 1,6-Dichloronaphthalene:  (c) 9-Bromoanthracene:  (d) 2-Methylphenanthrene: