Nickelocene is a chemical compound that consists of a nickel atom sandwiched between two cyclopentadienyl anions. It is classified as a metallocene, a type of organometallic compound where a metal is coordinated to cyclopentadienyl ligands. Nickelocene has a distinctive blue color and is known for its stability and unique electronic properties. This compound is of interest in various fields, including materials science and catalysis. Researchers study nickelocene for its potential applications in creating new materials and as a catalyst in chemical reactions. Its structure and properties make it a valuable subject for understanding metallocene chemistry.