Answer
Grignard reagents (RMgX) are organometallic compounds formed from the reaction of an alkyl, vinyl or aryl halide with magnesium metal. They are widely used in organic synthesis as nucleophilic reagents for the formation of carbon-carbon bonds. The general structure of a Grignard reagent is RMgX, where R represents an organic group (alkyl, alkenyl, aryl) and X represents a halide (Cl, Br, I).