On the polymorphs of pentafluorophenol and its 2 : 1 co-crystal with pentafluoroaniline

Abstract

The structure of the H form of pentafluorophenol (Cc, Z′ = 3) reported by Desiraju and coworkers (Chem. Commun., 2006, 555), is most probably the structure of 2 : 1 co-crystal of pentafluorophenol and pentafluoroaniline. However, at ambient conditions, pentafluorophenol can easily be obtained in the orthorhombic P2₁2₁2₁ form with Z′ = 3.