Mercury macrocyclic complexes: synthesis and crystal structures of {[HgCl(μ-Cl)(L1)][Hg(μ-Cl)2]}n (L1=1,4,7,10-tetraoxa-13-azacyclooctadecane), [Hg(L2)Cl2] (L2=1,4,7,10,13-pentaoxa-16-azacyclooctadecane) and [Hg(L3)Cl2] (L3=16-methyl-l,4,7,10,13-pentaoxa-16-azacyclooctadecane)

The mercury(II) complexes of the fifteen- and eighteen-membered ring macrocycles 1,4,7,10,-tetraoxa-13-aza-cyclopentadecane (L); 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (L) and 16-methyl-1,4,7,10,13-pentaoxa-16-azacyclooctadecane (L)have been prepared. The complexes {[HgCl(μ-Cl)(L)][Hg(μ-Cl)]}, [Hg(L)Cl] and [Hg(L)Cl] have been characterised by single crystal X-ray structural analysis. {[HgCl(μ-Cl)(L)][Hg(μ-Cl)]}, crystallises in the orthorhombic space group Pbca, with a=7.498(1), b=15.201(1), c=32.575(2) Å, U=3713(2) Å, Z=8, D=2.727 g cm, with R 0.039, R 0.040. The structure consists of a polymeric chain of five-coordinate mercury atoms [Hg(μ-Cl)] bearing [HgCl(μ-Cl)(L)] substituents. One mercury atom is located above the plane of the macrocyclic ligand L; bond lengths HgN 2.145(10), HgO 2.664(10)-2.806(9) Å. Two Cl ligands are located on the same side of the folded macrocyclic ring, Hg(1)Cl(1) and Hg(1)Cl(2) 2.291(4) and 3.129(4) Å, respectively, Cl(1)Hg(1)Cl(2) 102.37(13)°· [Hg(L)Cl] crystallises in the monoclinic space group P2/c, with a=7.648(1), b=7.858(1), c=15.366(3) Å, β=92.462(8)°, U=922.6(3) Å, Z=2, D=1.925 g cm with R 0.029, R 0.032. The mercury atom is eight-coordinate and is located at an inversion centre; bond lengths HgCl 2.327(2), HgN/O(1) 2.748(8), av. HgO distance 2.856 Å; the Cl(1)HgCl(1a) angle was 180°. [Hg(L)Cl] crystallises in the monoclinic space group C2/c, with a=11.751(4), b=10.504(3), c=31.38(2) Å, β=91.92°, U=3871(2) Å, Z=8, D=1.884 g cm and R 0.027, R 0.031. The metal ion is eight-coordinate (five oxygen, one tertiary amine and two chloride donors); there are two short (2.767(5), 2.753(6) Å), and three longer (2.961(6), 2.968(6), 2.922(6) Å) HgO bond lengths, with HgN 2.739(6) and HgCl 2.327(2) Å. The Cl(1)Hg(1)Cl(2) angle was 174.07(8)°