The central atom in the phosphorus tetrachloride cation (PCl4+) is phosphorus. Its chemical symbol is P.
In the structure of PCl4+, phosphorus is surrounded by four chlorine atoms. This forms a tetrahedral geometry around the phosphorus atom. The plus charge indicates that there is one less electron than in a neutral phosphorus atom, which affects the overall electron density and bonding characteristics. However, the central atom remains phosphorus, as it is the atom to which all other atoms in the compound are bonded.