A carbene is a type of reactive chemical species that contains a carbon atom with only two bonds instead of the usual four. This unique structure gives carbenes distinct properties, making them important in various chemical reactions. They can exist in two forms: singlet, where the carbon has paired electrons, and triplet, where the electrons are unpaired. Carbenes are often used in organic chemistry for synthesizing new compounds. They can participate in cyclopropanation, insertion reactions, and cross-coupling reactions, making them valuable tools for chemists. Their reactivity and versatility contribute to advancements in materials science and pharmaceuticals.