Bis(o-trifluoromethylphenyl)dithiophosphinic methyl ester

When bis(o-trifluoromethylphenyl)dithiophosphinic acid (1) is dissolved in methanol, crystals of bis(o-trifluoromethylphenyl)dithiophosphinic methyl ester (2) are formed. The structure of dithiophosphinic methyl ester (2) has been characterized via single-crystal X-ray diffraction and multinuclear NMR studies. Compound 2 is remarkable in that the dithiophosphinic (PS2) core is preserved during this transformation. The transformation to 2 suggests that the o-trifluoromethylphenyl groups on phosphorus assist in retaining the PS2 core, possibly by steric hindrance.