One of the most common ionic compounds that my element chlorine forms in nature is Sodium Chloride, or table salt. Chlorine forms a bond with Sodium to form a crystalline solid called NaCl. The positively charged Na ions, and negatively charged Cl ions are held together by an electrostatic force the creates an ionic bond. Another ionic compound formed would be Sodium Hypochlorite or bleach. This compound consists of three elements: Na, Cl, and O. Sodium Hypochlorite can be used in household cleaning products as well as for water treatment in pools. Hypochlorous Acid or HOCL, is also used as a disinfectant, a bleach, and an oxidizer. This compound is formed when Chlorine is mixed with water.
http://www.visionlearning.com/library/module_viewer.php?http://en.wikipedia.org/wiki/Sodium_hypochlorite
http://en.wikipedia.org/wiki/Hypochlorous_acid