Nucleophilic fluoroalkylation as an efficient avenue to achieve fluorinated polyimide monomers containing Csp3‐Rf from carbonyl compounds

Abstract Fluorinated polyimides (PIs) have gained increasing attention due to their high transparency and low dielectric constant. However, the access to fluorinated monomers is limited, with most of the fluorination based on transformation from C─H to C─F. This article presents a new avenue to achieve fluorinated monomers starting from wide range of carbonyl compounds. Nucleophilic fluoroalkylation on carbonyl using Ruppert's reagent has been employed to transform carbonyl (CO) into α‐trifluoromethylated alcohol followed by facile derivation into diamine containing Csp 3 ─CF 3 . The obtained symmetric fluorinated diamine para‐bis(1′‐[3‐amino‐6‐pyridinyloxy]‐1′‐trifluoromethyl)benzene (PAPyTB) show good modification effects on PIs. The PIs modified by PAPyTB exhibit the generally maintained optical transparency and T g . The mechanical properties of modified PIs show a wide range and decrease with increasing content of PAPyTB. Importantly, the solubility and hydrophobicity of the modified PIs increase with increasing loading of PAPyTB. Furthermore, the presence of trifluoromethyl groups in the polymer chain leads to reduced dielectric constant of the modified PIs, showing dielectric constant ( ε ′) 3.16 and dielectric loss ( ε ″) 0.0052 at 1 MHz and 298 K with 60% molar content of PAPyTB. This work indicates that nucleophilic fluoroalkylation is a new and efficient avenue to achieve fluorinated PI monomers with Csp 3 ─R f from a wide range of carbonyl compounds.