TRISPHAT (full name tris(tetrachlorocatecholato)phosphate(1−)) is an inorganic anion with the formula P(O2C6Cl4)−3 often prepared as the tributylammonium ((C4H9)3NH+) or tetrabutylammonium ((C4H9)4N+ salt.
The anion features phosphorus(V) bonded to three tetrachlorocatecholate (C6Cl4O2−2) ligands.
This anion can be resolved into the axially chiral enantiomers, which are optically stable (the picture shows the Δ enantiomer).
The TRISPHAT anion has been used as a chiral shift reagent for cations.
[1] It improves the resolution of 1H NMR spectra by forming diastereomeric ion pairs.