Arsine derivatives, platinum complexes

The induction period can be explained as the result of reactions a or /3. The first, proposed by Heck 89), requires that tetracarbonylnickel have basic properties, but this could not be proved. In fact, the protonation reaction of carbonyls and carbonyl derivatives has been studied by Wilkinson and co-workers 64) Ni(CO)4 does react with acids but, contrary to Fe(CO)5, gives no NMR signal—indicating the formation of a hydride. However, the basic properties of some systems have been recently shown in complexes with phosphines and arsines. The platinum (0) 39, 40) derivatives yield stable hydrides according to the following equilibria ... 

Phosphines and arsines containing more than one olefinic group were neglected as possible multidentate ligands until Hall prepared the tris (orfAo-vinylphenyl) derivatives of phosphorus, arsenic and antimony (tvpp, tvpa and tvps) and their platinum(II) (48) and rhodium(I) (49) complexes. 

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