A sulfonate is a salt or ester of a sulfonic acid. It contains the functional group R-SO2O-. ==Sulfonate salts== Anions with the general formula RSO2O− are called sulfonates. They are the conjugate bases of sulfonic acids with formula RSO2OH. As sulfonic acids tend to be strong acids, the corresponding sulfonates are weak bases. Due to the stabi... Found on http://en.wikipedia.org/wiki/Sulfonate