Solution Calorimetric Study of Ligand Exchange Reactions in the [Au(L)Cl] System (L = Phosphine and Phosphite)

The relative L-Au bond dissociation enthalpies of [Au(L)Cl] (L = tetrahydrothiophene (tht), PCynPh(3-n), [1,1'-bipheny1]-2-yldicyclohexylphosphine (Cy-JohnPhos), dicyclohexyl(2',6'-dimethoxy[1,1'-biphenyl]-2-yl)phosphine (SPhos), dicyclohexyl[2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine (XPhos), P(OPh)(3), P(O-2,4-(Bu2Ph)-Bu-t)(3), P((OPr)-Pr-i)(3), and the two enantiomers of 1,1', 1 ''-[phosphinidynetris[oxy-(1-S/R)-[1,1'-binaphthalene]-2',2-diyl]] tricyclo[3.3113,7]decane-1-carboxylic acid ester) are examined, These enthalpic values are examined in terms of the intrinsic steric and electronic properties of the ancillary ligand. Estimates of the absolute BDE for the investigated ligands are presented.