Transition Metal Complexes of a Constrained Phosphite Ester. IV. Compounds of Cobalt(I), Cobalt(III), Nickel(II), and Nickel(O)

Abstract

Cobalt and nickel complexes of 4-methyl-2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane (I), the 4-ethyl analog of I (I'), and 2,8,9-trioxa-l-phosphaadamantane (II) are described. Maximum coordination numbers for the metals are observed for the yellow [Co(P(OCH2)3CCH2CH3)B] +, colorless [Co(P(OCH2)3CCH2CH3)6] +3, yellow [Co(P(OCH)3(CH2)3)5] + and colorless [Co(P(OCH)3(CH2)3)6] +3 ions, all of which are diamagnetic. Calculations of Dq from ultraviolet spectra of the colorless cobalt complexes show that I' and II provide ligand fields of about the same strength as that of the cyanide ion. The yellow diamagnetic [Ni(P(OCH2)3CCH3)6] +2, [Xi(P(OCH2)3CCH2CH3)6] +2, and [Xi(P(OCH)3(CH2)3)6]+2 ions are also described and their possible configurations discussed. The reduction of the [NiLs] +2 ions (where L = I, I', or II) to the corresponding NiL4 complexes wherein nickel is zerovalent is also reported. © 1965, American Chemical Society. All rights reserved.