Dipole-moment measurements of metal chelates. Part II. Dipole moments of nickel(II), palladium(II), platinum(II), and cobalt(III) complexes of six fluorinated mercapto-β-diketones

Abstract

Dipole moments have been determined by static polarization measurements for the nickel(II), palladium(II), platinum(II), and cobalt(III) chelates of the fluorinated mercapto-β-diketones RC(SH):CHCOCF₃(R =m-MeC₆H₄, m-ClC₆H₄, m-BrC₆H₄, p-FC₆H₄, pClC₆H₄, and m,p-Cl₂C₆H₃). The moments indicate cis-square-planar configurations for the nickel, palladium, and platinum complexes and suggest a facial-octahedral configuration for the cobalt complexes. The variation of the dipole moments with R is considered to be dependent on: (a) the magnitude and vector directions of the Ph–X bond moments; (b) the inductive effect of the meta- and para-substituent on the phenyl ring; and (c) the mesomeric effect of the substituent X.