(Pentamethylcyclopentadiene)palladium complexes

Abstract

Reaction of 5-substituted-pentamethylcyclopentadienes (C₅Me₅Y) with palladium chloride gave complexes of type Pd(C₅Me₅Y)Cl₂. These complexes are probably monomeric. Consideration of the differences in the n.m.r. spectra of the complexes and free ligands leads to the conclusions that in Pd(C₅Me₅Y)Cl₂(Y = Et, CHClMe, or CH(OR)Me) the substituent Y is exo, while in Pd(C₅Me₅H)Cl₂ the H is endo to the metal, and that there is a deformation of the ligand on complex formation, probably towards a ‘homo-cyclobutadiene’ form.