A fluorinated bis(acyl)-containing compound of Formula (I), where R1, Ar, L, R2, R3, Rf, n, p and q are as defined in the claims, and a fluorinated polyester formed from the fluorinated bis(acyl) compound are described. More particularly, the fluorinated bis(acyl) has an aromatic ring bonded to two acyl groups plus at least one third group that contains a perfluoroalkylsulfonamido group. The fluorinated polyesters formed from the fluorinated bis(acyl)-containing compound can be used to provide a low energy surface with a relatively low refractive index compared to many other polyesters. A method of preparing a monosubstituted-arylene compound of formula Rf1-L2-CH2—Ar2—CH2—W, where Ar2, Rf1, L2, R6 and W are as defined in the claims by reaction of a compound of formula Rf1-L2-H with a compound of formula W—CH2—Ar2—CH2—W.