Comprehensive List of Polyatomic Ions

Polyatomic Cations and Unique Metallic Clusters

  • Ammonium Ion:

    • Formula: NH4+NH_4^+

    • Description: A common polyatomic cation found in various salts.

  • Mercury(I) Ion:

    • Formula: Hg22+Hg_2^{2+}

    • Description: Also known as the mercurous ion; it consists of two mercury atoms covalently bonded to each other with an overall charge of +2.

Carbon-Based Polyatomic Anions

  • Cyanide Ion:

    • Formula: CN−CN^-

  • Acetate Ion:

    • Formula: CH3CO2−CH_3CO_2^- or C2H3O2−C_2H_3O_2^-

    • Description: The conjugate base of acetic acid; both structural and molecular formula representations are commonly used.

  • Carbonate Ion:

    • Formula: CO32−CO_3^{2-}

  • Bicarbonate Ion (Hydrogen Carbonate Ion):

    • Formula: HCO3−HCO_3^-

    • Description: Formed by adding a hydrogen proton to a carbonate ion, reducing the negative charge by one.

  • Oxalate Ion:

    • Formula: C2O42−C_2O_4^{2-}

Nitrogen and Phosphorus Oxoanions

  • Nitrite Ion:

    • Formula: NO2−NO_2^-

  • Nitrate Ion:

    • Formula: NO3−NO_3^-

  • Phosphate Ion:

    • Formula: PO43−PO_4^{3-}

  • Hydrogen Phosphate Ion:

    • Formula: HPO42−HPO_4^{2-}

  • Dihydrogen Phosphate Ion:

    • Formula: H2PO4−H_2PO_4^-

Sulfur-Based Polyatomic Anions

  • Sulfite Ion:

    • Formula: SO32−SO_3^{2-}

  • Sulfate Ion:

    • Formula: SO42−SO_4^{2-}

  • Hydrogen Sulfate (Bisulfate) Ion:

    • Formula: HSO4−HSO_4^-

    • Description: Formed by the partial neutralization of sulfuric acid.

Halogen Oxoanion Series

Chlorine-Based Ions

  • Hypochlorite Ion: ClO−ClO^-

  • Chlorite Ion: ClO2−ClO_2^-

  • Chlorate Ion: ClO3−ClO_3^-

  • Perchlorate Ion: ClO4−ClO_4^-

Bromine-Based Ions

  • Hypobromite Ion: BrO−BrO^-

  • Bromite Ion: BrO2−BrO_2^-

  • Bromate Ion: BrO3−BrO_3^-

  • Perbromate Ion: BrO4−BrO_4^-

Iodine-Based Ions

  • Hypoiodite Ion: IO−IO^-

  • Iodite Ion: IO2−IO_2^-

  • Iodate Ion: IO3−IO_3^-

  • Periodate Ion: IO4−IO_4^-

Transition Metal and Additional Polyatomic Anions

  • Hydroxide Ion:

    • Formula: OH−OH^-

  • Chromate Ion:

    • Formula: CrO42−CrO_4^{2-}

  • Dichromate Ion:

    • Formula: Cr2O72−Cr_2O_7^{2-}

  • Permanganate Ion:

    • Formula: MnO4−MnO_4^-

  • Peroxide Ion:

    • Formula: O22−O_2^{2-}

  • Thiocyanate Ion:

    • Formula: SCN−SCN^-