Synthesis and Applications of Perfluoroalkylated Organophosphorus Ligands

This research concerns a new generation of phosphorus ligands bearing short and branched perfluoroalkyl or perfluoropolyether substituents of the fluorine content and their coordination chemistry as an alternative ligands and metal complexes having a potential application in fluorous biphase system in all common organic solvents. A series of new perfluoroalkylated arylphosphines with the general formula of P(C₆H₄-p-R)₃, where R = OC₂H₄OC₄F₉, OCH₂C₄F₉, or CH₂OCF₂ (OCF₂CF₂)₂OCF₃; aryl phosphonic acid ligands [R-p-C₆H₄P(O)(OH)₂], where R = OCH₂CH₂C₄F₉ or OCH₂CF₂ (OCF₂CF₂)₂OCF₃, and alkyl phosphinite and phosphonite ligands (Ph)ₓP(OR)₃₋ₓwhere R = CH₂CH₂C₄F₉, CH(CH₂OC₄F₉)₂, or CH₂CF₂(OCF₂CF₂)₂OCF₃ have been synthesised and fully characterised by ¹H, ¹⁹F, ³¹P, and ¹³C NMR spectroscopies, and mass spectrometry. The perfluoroalkylated phosphine, phosphinite, phosphonite ligands have been reacted with transition metal complexes to form complexes of the type cis and trans-[PtCl₂L₂], and [Cp*RhCl₂L]. The complexes were isolated and characterised using ¹H, ¹⁹F, and ³¹P NMR spectroscopies, mass spectrometry, and X-ray crystallography. The derivatised phosphonic acid ligands have been reacted with transition metal complexes as dianionic bidentate ligands to form coordination complexes of the type [Pt(O₃PR)(PPh₃)₂] and zirconium phosphonate Zr[O₃PC₆H₄-4-R]₂. The platinum complexes have been fully characterised by ¹H, ¹⁹F, and ³¹P NMR spectroscopies, and mass spectrometry. The zirconium phosphonates are immiscible in all the organic solvents. Therefore the characterisation was limited to ESEM and IR studies. A study into potential fluorous solubility of the synthesised ligands and their metal complexes was also undertaken. In this regard, the influence of the fluorine contents, and the electronic insulating groups on the organic/fluorous solubility rate was also examined.