Phosphorus-31 and mercury-199 N.M.R. studies of mercury(II) complexes with some tertiary phosphines

Abstract

Phosphorus-31 and mercury-199 n.m.r. techniques have been used to investigate the formation of mercury(II) complexes HgA₂(phos)_1-4 [where A = ClO₄^-, NO₃^-, CF₃COO^-, CH₃COO^-, SCN^-, CN^-, Cl^-, Br^-, I^- and phos = P(4-ClC₆H₄)₃, P(4-CH₃OC₆H₄)₃, P(2-CH₃OC₆H₄)₃, P(4-CH₃C₆H₄)₃, P(2-CH₃C₆H₄)₃, P(3-CH₃CH₆H₄)₃, PBu₃, P(C₆H₁₁)₃ and PPh₃] in dichloromethane solution. The number of phosphines coordinated to the mercury depends upon the steric requirements of the phosphine and the nature of the anion A.

Phosphorus-31 and mercury-199 chemical shifts and coupling constant data imply coordination of all the anions, except perchlorate, to mercury. Mercury chemical shifts are discussed in terms of electron density at the metal and coordination number of the metal.