Frustrated Lewis pair-ligated tetrelenes.

The reactivity of [PB{SiX 2 }] (X = Cl, Br; PB = 1,2- i Pr 2 (C 6 H 4 )BCy 2 ; E = Si, Ge) adducts is described, with an initial focus on reduction attempts to access [PB{E}] x species; however, in all cases only free PB ligand was formed as the soluble product. Moreover, computations were performed to evaluate the energy penalty associated with EX 2 dissociation from the PB chelates. Moving up the periodic table, the formal methylene adduct [PB{CH 2 }] was isolated and its reactivity was compared with its heavier element congeners of [PB{EH 2 }]. We also introduce new phosphine-borane frustrated Lewis pair (FLP) chelates and explore preliminary coordination chemistry with these ligands.