Organophosphate
Organophosphates (also known as phosphate esters) are a class of organophosphorus compounds with the general structure O=P(OR). They can be considered as esters of phosphoric acid. Like most functional groups organophosphates occur in a diverse range of forms, with important examples including key biomolecules such as DNA, RNA and ATP, as well as many insecticides, herbicides, and nerve agents.
Phosphite ester
In chemistry a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR). They can be considered as esters of an unobserved tautomer phosphorous acid, HPO, with the simplest example being trimethylphosphite, P(OCH). Some phosphites can be considered esters of the dominant tautomer of phosphorous acid (HP(O)(OH)). The simplest representative is dimethylphosphite with the formula HP(O)(OCH). Both classes of phosphites are usually colorless liquids.