The molecular formula of diphenylmethane is . How many total structural isomers are possible when ex — Isomerism and Stereochemistry Chemistry Question
Question
The molecular formula of diphenylmethane is $C_{13}H_{12}$. How many total structural isomers are possible when exactly one of the hydrogen atoms is replaced by a chlorine atom?
💡 Solution & Explanation
Diphenylmethane consists of two benzene rings connected by a central methylene ($-CH_2-$) bridge ($Ph-CH_2-Ph$). To find the monochloro derivatives, we look for all non-equivalent positions. These are: (1) Ortho position on either ring, (2) Meta position on either ring, (3) Para position on either ring, and (4) The central methylene bridge carbon. Substitution on the second ring yields identical structures due to symmetry. Thus, exactly 4 structural isomers exist.