Synthesis, Crystal Structure, and Spectroscopic Study of Lead Monochloroacetate, Pb(ClCH2COO)2

Abstract

Crystals of lead monochloroacetate, Pb(ClCH₂COO)₂, were obtained in the reaction of lead carbonate and aqueous chloroacetic acid. The compound crystallizes in the monoclinic system (space group P2₁/c) with the unit-cell parameters a = 10.8346(6) Å, b = 7.7239(4) Å, c = 10.1484(5) Å, β = 106.542(5)°. Like in other medium- and long-chain lead carboxylates, the crystal structure of lead monochloroacetate is layered. Lead atoms are located in distorted seven-vertex PbO₇-polyhedra, which share edges and form layers. Features of the crystal structures of lead salts of carboxylic acids with unbranched hydrocarbon radicals are discussed. In particular, salts of lead(II) n-alkyl carboxylates with the general formula Pb(C_nH\(_{{2n + 1}}\)COO)₂, despite belonging to different symmetry and space groups (monoclinic P2₁/m for n = 2 and 3, triclinic P\(\bar {1}\) for n = 4–9, and monoclinic P2₁/c for Pb(ClCH₂COO)₂), are characterized by the same arrangement of molecules, so they can be considered structurally related.