First observation of alkali metal ion induced trans-cis isomerization of palladium(II) phosphane complexes containing crown ether moieties

Abstract

Ion switches: The addition of small metal ions (such as Li+ and Na+) to transpalladium(II) complexes of PPh2-substituted benzo[15]crown-5 and benzo[18]-crown-6 results in the formation of 1:1 trans adducts. However, the addition of large alkali ions (such as K+, Rb+, and Cs+) enforces the complexes to undergo a trans-cis isomerization to enable formation of intramolecular sandwich adducts (see schematic representation).