Organic acid anhydride case, the name of the acyl group is enclosed in parentheses to avoid ambiguity in the name, e.g., (thioacetic) anhydride (CHC(S)OC(S)CH). When two acyl groups are attached to the same sulfur atom, the resulting compound is called a thioanhydride, e.g., acetic thioanhydride ((CHC(O))S). Organic acid anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride
Hexafluorophosphoric acid Hexafluorophosphoric acid Hexafluorophosphoric acid is the inorganic compound with the chemical formula HOPF. Although the formula is often written as HPF, this compound is only available as the hydrate. This strong Brønsted acid features a non-coordinating anion, hexafluorophosphate (). It is formed from the reaction of hydrogen fluoride with phosphorus pentafluoride. Like many strong acids, hexafluorophosphoric acid is not isolable but is handled only in solution. Its aqueous solutions consist of hydronium ion, , and . Additionally, such solutions often contain products derived from hydrolysis of the P-F bonds, including , , and , and their conjugate bases. Hexafluorophosphoric acid