Crystal structure and fluxional behavior of novel Pd(II) allyl complexes containing a potentially tridentate S,N,S ligand: an example of selective syn-anti isomerism
摘要:
When the potentially tridentate ligand 2,6-bis(methylthiomethyl)pyridine (SNS) is coordinated to the palladium(II) allyl fragment a bidentate 'arm-off' eta(3)-allyl complex is separated in the solid state. In solution, the presence of the non-coordinated sulfur atom induces a syn-anti isomerism at very low temperature in all the studied complexes. In the case of the [Pd(eta(3)-1,1-Me2C3H3) (SNS)](+) cation the syn-anti isomerism becomes selective. The activation parameters for such an isomerism are in accordance with an associative concerted mechanism involving an 18-electron transition state. (C) 1998 Elsevier Science S.A. All rights reserved.