Heterolytic splitting of H—X bonds at a cationic (PNP)Pd center

摘要

The (PNP)PdOTf complex is a suitable synthetic equivalent of the [(PNP)Pd]~+ fragment in reactions with various HX substrates. The [(PNP)Pd]~ + fragment either simply binds HX molecules as L-type ligands (X = NH_2, PCy_2, imidazolyl) or heterolytically splits the H-X bond to produce [(PN(H)P)Pd-X]~+ (X = H, CCR, SR). DFT calculations analyze the relative energetics of the two outcomes and agree with the experimental data. Calculations also allow to assess the unobserved Pd(iv) isomer [(PNP)Pd(H)_2]~+ and validate its unfavourability with respect to the Pd(II) isomer [(PN(H)P)PdH]~+.