COMPLEXES OF NICKEL(2) CYANIDE WITH DITERTIARY PHOSPHINES

The preparation and characterization of the diamagnetic complexes of Ni(CN)2 with the ditertiary phosphines (C6H5)2P-(CH2)nP(C6H5)2 (n = 2, 3, or 4) are reported. In contrast to the analogous complexes with the nickel halides, the complexes with Ni(CN)2 are shown to contain not only chelating but also nonchelating and bridging diphosphines. The complexes are of the type Ni[(C6H5)P(CH2)nP(C6H5)2]m(CN)2, where m = 1, 1.5, or 2. The visible spectra show that the complexes with m = 1.5 or 2 are five-coordinate. The five-coordinate compound Ni[(C6H5)8P(CH2)8P(C6H5)2]P(C4H9)8(CN)2 containing one ditertiary phosphine and one tertiary phosphine is also reported. The unusual composition of some of these complexes is attributed to the tendency of nickel(II) cyanide to coordinate three phosphorus atoms of trisubstituted phosphines. © 1968, American Chemical Society. All rights reserved.