2-substituted imidazole and benzimidazole corrosion inhibitors

A formulation for inhibiting corrosion of a metal surface, the formulation comprising one or more phosphorus-containing compounds and a compound of formula (I) or (II);

• wherein formula (I) is
• wherein each X is the same or different, and each is selected from the group consisting of hydrogen, C1-C16 alkyl, aryl, C2-C16 alkenyl, C2-C16 alkynyl, heteroaryl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
• Y is selected from the group consisting of hydroxyl, halogen, oxo, alkoxy, thiol, alkylthio, amino, hydrogen, and aminoalkyl;
• Z is selected from the group consisting of carbon and nitrogen;
• R1 is selected from the group consisting of hydrogen, deuterium, C1-C16 alkyl, aryl, C2-C16 alkenyl, C2-C16 alkynyl, heteroaryl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, hydroxyl, and carbonyl;
• R2 and R3 are selected from the group consisting of hydrogen, halogen, hydroxyl, aryl, phenyl, heteroaryl, benzyl, alkylheteroaryl, carbonyl, C2-C16 alkenyl, C2-C16 alkynyl, C3-C8 cycloalkyl, and C1-C16 alkyl;
• and
• m is 1, 2, 3, or 4;
• or
• a salt thereof;
• and
• formula (II) is
• wherein each of X and Y is the same or different, and each is selected from the group consisting of hydrogen, C1-C16 alkyl, aryl, C2-C16 alkenyl, C2-C16 alkynyl, heteroaryl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
• R is selected from the group consisting of hydrogen, deuterium, C1-C16 alkyl, aryl, C2-C16 alkenyl, C2-C16 alkynyl, heteroaryl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, hydroxyl, and carbonyl;
• m is 1, 2, 3, or 4;
• and
• n is 1, 2, 3, or 4;
• or
• a salt thereof;
• with the proviso that when the imidazole is benzimidazole and X and R are both hydrogen, then the pyridine ring is 2-pyridyl.