Abstract Two new sterically demanding diaminophosphinothiolate ligands (HL 1 and HL 2) have been prepared and the X-ray crystal structure of the Li salt of HL 2 has been determined. The complex [Pd (L 1) 2] was fully characterized, but in contrast to other phosphinothiolates, complexes with the M (L) 3 stoichiometry could not be prepared. Reaction of LH 1 with Ni (II) led to cleavage of the arythiolate group and isolation of a ...