Bifunctional pincer-type organometallics as substrates for organic transformations and as novel building blocks for polymetallic materials

The reactivity of the bifunctionalized ligand NC(Br)N\ 1 [IC6H2(CH2NMe2)(2)-3,5-Br-4] has been studied as a versatile synthon for organic and/or organometallic synthesis. Chemoselective metalation (M = Pd, Pt, LI) at the C-aryl-1 or C-aryl-Br bonds was achieved by choosing the appropriate metal precursors. In this way a series of Pt-II and Pd-II complexes were prepared that have a second functional group available for further reactions. These Pt-II and Pd-II complexes were subjected to a wide range of organic and organometallic reactions, revealing the remarkable stability of their M-C sigma-bond and opening an easy route for the synthesis of mono- and (hetero)bimetallic building blocks. The scope of the chemistry of such building blocks shows that they are good candidates for use in the synthesis of dendrimers, bioorganometallic systems, or polymetallic materials. The X-ray crystal structures of the most representative complexes (2, 3a, 19, 20, and 24) are also reported.