Reactivity of Ph2(2-C5H4N)PSe towards Ru3(CO)12 and mononuclear MCl2(PhCN)2 (M=Pd or Pt) complexes

The behavior of the Ph2(2-C5H4N)PSe ligand in the reactions with Ru3(CO)12 and the mononuclear complexes MCl2(PhCN)2 (M=Pd or Pt) has been investigated. The reaction with Ru3(CO)12 is characterized by PSe bond cleavage, affording the 48-electron compound [Ru3(μ3-Se)(μ-PPh2)2(μ-C5H4N)(μ3-C5H4N)(CO)6] (1), the open triangular 50-electron nido clusters [Ru3(μ3-Se)2(CO)9−n{P(2-C5H4N)Ph2}n] (2 and 3, for n=1 and 2, respectively) and the octahedral 62-electron closo cluster [Ru4(μ4-Se)2(CO){μ-P,N-Ph2(2-C5H4N)P}] (4). The cluster 1 derives by the multiple fragmentation of two phosphine ligands on the metal triangle involving the PSe and PC bond cleavages. The molecular structure of 4 shows a short Ru⋯P non-bonding separation that can be viewed as a preliminary step towards the PC bond cleavage. In the reactions with MCl2(PhCN)2 (M=Pd, Pt) Ph2(2-C5H4N)PSe remains intact affording mononuclear neutral complexes of the type MCl2{N,Se-Ph2(2-C5H4N)PSe}. The crystal structure of the palladium derivative 5 has been determined by X-ray diffraction methods.