Synthesis and characterization of new Ni and Pd hydride-species: Their catalytic activity in the oligomerization of methylacrilate

The implication of hydride-species in the oligomerisation of methylacrilate has been since long postulated and only little direct evidence has been reported. As an outcome of our studies on the synthesis and reactivity of alkylammonium (or iminium) tetraphenylborates, we have synthesised Ni and Pd cationic complexes [trans-(H)Ni(PCy3)2(h1(N)-PhCH2N=CMe2)BPh4, (1); [Ni(h3-(C3H5)(PCy3)(NH3)]BPh4, (2); [HPd(dppe)2]BPh4,(3); [h3-(C3H3)Pd(dppe)]BPh4. Ni complexes have been completely characterised in solution and in the solid state. Pd-hydride complex has been characterised in solution, itsinstability and reactivity made difficult to carry out a study in the soli state. We have compared the reactivity of compounds (1) and (3) and found that Hydride (1) is active catalyst for the oligomerisation of methylacrylate (MA). (3) polymerises MA, (2) and (4) are totally inactive, also after several hours.