Pool chlorine is not a single chemical compound but rather a generic term for chlorine-based chemicals used to disinfect swimming pools. The most common forms are:

* Sodium hypochlorite (NaClO): This is the most common form of pool chlorine, usually found in liquid bleach.

* Calcium hypochlorite (Ca(ClO)₂): This is a granular or tablet form of chlorine that is often used in pool chlorinators.

* Trichloroisocyanuric acid (C₃Cl₃N₃O₃): This is a stabilized form of chlorine that is often used in slow-dissolving tablets.

So, there's no single "chemical formula for pool chlorine", but the three listed above are the most common and active ingredients.