Triflic acid acid and its conjugate base CFSO, known as triflate, resist oxidation/reduction reactions, whereas many strong acids are oxidizing, e.g. perchloric or nitric acid. Further recommending its use, triflic acid does not sulfonate substrates, which can be a problem with sulfuric acid, fluorosulfuric acid, and chlorosulfonic acid. Below is a prototypical sulfonation, which HOTf does "not" undergo: Triflic acid fumes in moist air and forms a stable solid monohydrate, CFSOH·HO, melting point 34 °C. The triflate ligand is labile, reflecting its low basicity. Trifluoromethanesulfonic acid exothermically reacts with metal carbonates, hydroxides, and oxides. Illustrative is the synthesis of Cu(OTf). Chloride ligands
Methylmalonic acid Methylmalonic acid Methylmalonic acid (MMA) (conjugate base methylmalonate) is a dicarboxylic acid that is a "C"-methylated derivative of malonate. The coenzyme A linked form of methylmalonic acid, methylmalonyl-CoA, is converted into succinyl-CoA by methylmalonyl-CoA mutase, in a reaction that requires vitamin B as a cofactor. In this way, it enters the Krebs cycle, and is thus part of one of the anaplerotic reactions. Increased methylmalonic acid levels may indicate a vitamin B deficiency. However, it is sensitive (those with the disease almost always test positive) but not specific (those that do not have the disease do not always test negative).