| Abstract
| - 1H and 19F PGSE diffusion studies on cationic mono- and trinuclear iridium complexes containing a PHOX chiral P,N-auxiliary are reported. The counterion and solvent dependence of the ion-pairing is discussed.
- 1H and 19F pulsed gradient spin−echo (PGSE) diffusion studies on cationic mono- and trinuclear iridium complexescontaining the PHOX chiral P,N-auxiliary (S)-4-tert-butyl-2-[2-(di-o-tolylphosphino)phenyl]-4,5-dihydrooxazole withthe anions BF4-, PF6-, OTf-, B(C6F5)4-, and BArF- in methanol, chloroform, methylene chloride, and1,2-dichloroethane are reported. In chloroform, the anion and cation within each salt afford almost the same,relatively small, diffusion constant (D-value) suggesting strong ion-pairing. In methanol, the D-value for the cationis the same in the five mononuclear salts, suggesting that the cation is moving independently of the anion (noion-pairing). In methylene chloride and 1,2-dichloroethane the diffusion data suggest a mixed picture for the fiveanions. While the smaller BF4-, PF6-, and OTf- anions do not affect the translation of the cations, the largerboron-based anions B(C6F5)4- and BArF- clearly slow the motions of the cations. However, it would seem that forall five anions there is somebut not completeion pairing in these two solvents.
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