Phosphite complexes of nickel

Metal basicity is also exhibited by phosphine and phosphite complexes of nickel(0), which can be protonated by acids of various strengths ... 

Nickel.— Phosphine and phosphite complexes of nickel(0) react with strong acids to produce complexes [NiHL4]+. Reaction with weak acids may proceed further, with attack of the anion at the nickel. Thus the complex Ni(LL)a, where LL = l,4-bis(diphenylphosphino)butane, reacts with hydrogen cyanide to form firstly a hydride, which reacts quickly with cyanide to give the bimolecular intermediate Ni2(CN)2(LL)a. The ultimate products are the nickel(n) monomer Ni(CN)2(LL)2 and dimer [Ni(CN)2-(LL)]2. Ni(PPh3)4 undergoes normal oxidative elimination reactions with aryl halides to produce the new nickel(n) complexes Ni(aryl)(X)-(PPh3)2. ... 

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