Heavy-Metal Complexes With (2-Chlorophenoxy)acetic Acid: The Crystal Structures of Polymeric Mercury(II) (2-Chlorophenoxy)acetate and the Thallium(I) (2-Chlorophenoxy)acetate(2-Chlorophenoxy)acetic Acid Adduct

Abstract

The crystal structures of the mercury(II) and thallium(I) complexes with (2-chlorophenoxy)acetic acid have been determined by X-ray diffraction, and refined to residual values R 0.040 and 0.060 for 1130 and 1612 observed reflections respectively. catena-[ Bis {(2- chlorophenoxy ) acetato }mercury(II)] is monoclinic, space group Cc with Z 4 in a cell of dimensions a 25.449(7), b 7.335(2), c 10.154(1) Ǻ, β 112.83(2)°. Mercury is bonded linearly to two carboxylate oxygens [Hg-O, 2.02(1), 2.04(1)Ǻ; O-Hg-O, 175.5(6)°] and forms a polymer link to a third oxygen [Hg-O, 2.60(2)Ǻ; O-Hg-O, 88.8(6), 87.6(7)°] giving triangular coordination about the mercury. The complex adduct {(2-chlorophenoxy) acetato }thallium(I)-(2-chlorophenoxy)acetic acid is monoclinic, space group C2/c with a 27.97(1), b 4.798(1), c 13.389(6) Ǻ, β 94.23(3)° and Z 4. This is an example of an ML.LH compound, having twofold rotational symmetry with the acid proton not located. The Tl -O bonds to each ligand molecule are 2.826(7)Ǻ with two longer bonds to adjacent carboxylate oxygens [3.002(7)Ǻ] completing a distorted square-planar stereochemistry about thallium. This results in a linear polymer structure.