Diphenic acid
Diphenic acid, also called dibenzoic acid, is an organic compound with the formula C14H10O4. It is the most studied form of the dicarboxylic acids that come from biphenyl. It is a white solid with a molar mass of 242.23 g/mol and a melting point of about 235.5 °C.
How it is made
- In the lab, diphenic acid can be prepared from anthranilic acid by forming a diazonium salt and reducing it with copper(I).
- It can also be produced by oxidizing phenanthrene. Peracetic acid (made from acetic acid and hydrogen peroxide) can do this.
- Other oxidants such as hydrogen peroxide, chromium trioxide, potassium dichromate, or potassium permanganate can first form phenanthrenequinone, which is then oxidized to diphenic acid.
- Phenanthrenequinone can be boiled with alcoholic potassium hydroxide to give the diphenic acid potassium salt, and it can also be made by photo-oxidation.
What it does and its features
- Diphenic acid can form coordination polymers with metals.
- It exhibits atropisomerism, meaning it can exist as stable mirror-image forms.
- It can form an internal anhydride with a seven-membered ring fused to the two benzene rings.
This page was last edited on 2 February 2026, at 15:36 (CET).