“…For the all-trans isomers, the 19 F NMR resonances occur at substantially lower frequencies and the 2 J PF coupling constants are larger than those for the cis-difluoride isomers, as expected for the F-trans-F and F-cis-F arrangements. 13,[21][22][23][24] In the oxidations of the a-diimine complexes, the corresponding iridium(III) difluoride cations are formed as the single F-trans-F isomers, trans-,cis- 2), for which the shifts in d F to low frequency, in comparison to those for the related COD-complexes, mirror those for the related pairs of monodentate phosphine complexes.…”