1,3-Indandione

1,3-Indandione is an organic compound with the molecular formula C9H6O2. It is a yellowish crystalline solid that is used in the production of certain dyes and pigments. The compound is derived from indene via oxidation (dehydrogenation) and is a type of diketone.

Structure and Properties

1,3-Indandione is a diketone, meaning it contains two carbonyl groups. The carbonyl groups are located at the 1 and 3 positions of the indane ring system, hence the name 1,3-indandione. The compound is planar, which is typical for compounds that are fully conjugated. The conjugation also contributes to the compound's yellow color.

Synthesis

1,3-Indandione can be synthesized from indene by a two-step process that involves oxidation and dehydrogenation. The oxidation step can be performed using a variety of oxidizing agents, such as chromic acid or potassium permanganate. The dehydrogenation step typically involves heating the oxidized product in the presence of a catalyst, such as palladium on carbon.

Applications

1,3-Indandione is used in the synthesis of a variety of dyes and pigments. These include vat dyes, which are used in textile dyeing, and pigments used in printing inks. The compound is also used in the production of certain types of pesticides.

Safety and Environmental Concerns

Like many organic compounds, 1,3-indandione can be harmful if ingested or inhaled, and it can cause skin and eye irritation. It is also potentially harmful to the environment, particularly aquatic ecosystems.