Ask AI: What are complex ions

Complex ions are a type of chemical species that consist of a central metal atom or ion bonded to one or more ligands. Ligands are molecules or ions that donate electron pairs to the metal atom or ion through a process called coordination, forming coordinate covalent bonds. The overall structure has a net electrical charge, which can be positive or negative. The central metal atom or ion, typically a transition metal or a metal from the lanthanide or actinide series, has empty orbitals that can accept the electron pairs provided by the ligands. Ligands can be a variety of substances such as water molecules, ammonia, or halide ions, which surround and stabilize the central metal atom or ion. Complex ions have various applications in chemistry, including transition metal chemistry, biological systems, and analytical chemistry. They are involved in coordination compounds, catalysts, and have roles in the active sites of many metalloproteins and enzymes. An example of a complex ion is the hexaaquachromium (III) ion, [Cr(H2O)6]³⁺, where the central chromium (III) ion is surrounded by six water molecules acting as ligands.