Polyfluorinated Pd(II)-3,5-di-tert-butylsalicylaldimenes complexes: Synthesis, structure, spectroscopy, redox behaviors and catalytic activity

Abstract

A series of new polyfluorinated palladium(II) complexes (7–12) of N-polyfluorophenyl-3,5-di-tert-butylsalicylaldimines (1–6) have been synthesized. They were characterized by analytical, spectroscopic (UV/Vis, IR, 1H NMR, and ESR), electrochemical methods and their chemical oxidation and hydrogenation catalytic activity were studied. The X-ray crystal structure analysis of bis[N-(3,5-di-tert-butylsalicylidene)-F5Ph]Pd(II) (12) revealed a slightly distorted square-planar trans-PdN2O2 geometry around the palladium center. The UV/Vis and EPR results indicate that chemical oxidation of 7–10 by Ce(IV) in CHCl3 generates relatively stable Pd(II)–phenoxyl radical complexes (g=2.0044–2.0062). The results of chemical and electrochemical oxidation of 1–12, as well as the catalytic activity of 7–10 complexes in the hydrogenation of PhNO2 were presented.