Method for oxidation of sulfur-containing compounds

A method of removing sulfur-containing compounds from a fluid, comprising:

• contacting the fluid and sulfur-containing compounds with a catalyst in the presence of an oxidant to produce an oxidized sulfur-containing compound;
• and then
• separating the oxidized sulfur-containing compound from the fluid, wherein
• the catalyst has the structure
• wherein
• M is a metal,
• axial ligand L is a solvent molecule or absent,
• at each occurrence, RA and RB are independently chosen from —H, halide, an organic group, and a hydrophilic group, or RA and RB together form a fused aromatic ring with the ring upon which RA and RB are substituted, RA and RB together having the structure:
• and
• at each occurrence, R1, R2, R3, R4, R5, and R6 are each independently chosen from —H, halide, an organic group, a hydrophilic group, a salt thereof, a substituted or unsubstituted (C1-C50)hydrocarbyl ester thereof, and a combination thereof;
• and
• wherein contacting the fluid and the sulfur-containing compounds to produce the oxidized sulfur-containing compound comprises producing the oxidized sulfur-containing compound from a compound that is a thioether or that has the structure
• wherein each of X and Y is independently C1-C20 alkyl, C6-C10 aryl or C2-C10 heteroaryl, each of which may be optionally substituted, wherein X and Y are optionally linked so as to form a ring.