Methods of using ionic liquids as corrosion inhibitors

A method of inhibiting corrosion of a metallic surface in contact with an acidic or aqueous fluid comprising contacting the acidic or aqueous fluid with a corrosive inhibiting effective amount of an ionic liquid of the formula:

• R1R2R3A+R8A+R5R6R7X− (III)
• wherein:
• each A is nitrogen;
• and
• X is an anion selected from the group consisting of sulfur containing anions and hydroxycarboxylates;
• and
• wherein R1, R2, R3, R4, R5, R6 and R7 are independently selected from the group consisting of benzyl;
• alkylbenzyl, or oxyalkyl;
• a straight or branched alkyl group, an alkylbenzyl group, an arylalkyl group, a straight or branched chain alkenyl group, a hydroxyalkyl group or a hydroxyalkylbenzyl group;
• and a polyoxyalkylene group;
• and R8 is a straight or branched alkylene group, an alkylene oxyalkylene, or an alkylene polyoxyalkylene or a zwitterion.