Reactions of low-valent metal complexes with fluorocarbons. Part VII. Bis(triphenylphosphine)(π-ethylene)nickel and tetrakis(methyldiphenylphosphine)nickel

Abstract

Bis(triphenylphosphine)(π-ethylene)nickel reacts with hexafluoroacetone to form (Ph₃P)₂Ni[(CF₃)₂CO], and with chloro- and bromo-trifluoroethylene to give the vinyl complexes trans-(Ph₃P)₂Ni(CF:CF₂)X [X = Cl or Br]. A cis–trans mixture of 1,2-dichloro-1,2-difluoroethylene reacts similarly forming a mixture of trans-(Ph₃P)₂Ni(cis-CF:CFCl)Cl and trans-(Ph₃P)₂Ni-(trans-CF:CFCl)Cl. Analogous reactions take place with tetrakis(methyldiphenylphosphine)nickel. Hexafluoropropene, hexafluorocyclobutene, 1,1-difluoroethylene, and monofluoroethylene displace ethylene from (Ph₃P)₂Ni(C₂H₄) to afford (Ph₃P)₂Ni(fluoro-olefin) complexes; whereas trifluoroethylene gives the compound (Ph₃P)₂Ni(CF₂CFH)₂, postulated to contain a five-membered C₄Ni ring. The nickel(III) complexes (Ph₃P)₂Ni(R_F)l₂(R_F= CF₃ or C₃F₇) are formed when R_Fl is reacted with (Ph₃P)₂-Ni(C₂H₄). Pentafluorobenzoyl chloride reacts with (Ph₃P)₂Ni(C₂H₄) to form (Ph₃P)₂Ni(C₆F₅)Cl.