Reaction of phosphorus ylides of the type X–C 6H 4–COCH PAr 3 (X = Cl and NO 2; Ar = phenyl and p-tolyl) with Hg(NO 3) 2 · H 2O in equimolar ratios using methanol as solvent are reported. X-ray crystal structure analysis of [Hg(ClC 6H 4C(O)CHPPh 3)(NO 3)(μ-NO 3)] n · (DMSO) n shows that the 1:1 complex adopts the noncentrosymmetric polymeric structure in the solid state with NO - 3 anion bridges. Variation of temperature or concentration in a 31P NMR study indicates that the disappearance of satellites, due to coupling to 199Hg, occurs at increasing temperature or decreasing concentration.