Organometallic Platinum(II) and Palladium(II) Complexes as Donor Ligands for Lewis-Acidic d^(10) and s^2 Centers

Square-planar palladium(II) and platinum(II) complexes with a high-lying filled d_(z²) orbital can act as metalloligands for Lewis-acidic metal centers such as d^(10) and s^2 cations. This behavior is promoted by hard ligands such as σ-bound hydrocarbyl ligands. A wide diversity of structural motifs based on this kind of donor–acceptor metal–metal bonds has been discovered in the last decades. This chapter reviews the coordination chemistry of metalloligands derived from alkyl, aryl, alkynyl, and carbene complexes of palladium(II) and platinum(II). The specific reactivity of the resulting bimetallic complexes is also addressed.