Popis: |
We report an experimental study, with accompanying DFT calculations, on a series of heterobimetallic complexes with Pd(II) and Cu(I), Ag(I), or Au(I). The isolable pincer complexes are models for the intermediates and transition state for the transmetalation step in Sonogashira and Negishi coupling reactions, among which, according to the DFT calculations, only the transition state has the two metal centers within bonding distance. Furthermore, we report a substituted version of an analogous heterobimetallic complex in which a competing dissociation sets an upper-bound on the strength of the |