Complexes with Hg(II) and macrocyclic ligands

The crystal structures of 1,4,7,10,13,16-hexaoxa-cyclooctadecane dicyano mercury(II) monohydrate, C₁₄H₂₄HgN₂O₆·H₂O, 1, and 2,5,8,11,18,21,24,27-octaoxa-tricyclo[26.4.0.0_12,17]-dotriconta-1(28),12,14,16,29,31-hexaene dicyano mercury(II) monohydrate, C₂₆H₃₂HgN₂O₈·H₂O, 2, were determined: 1 crystallizes in the trigonal space group R3¯ with cell dimensions a = 11.7842(1) and c = 12.0316(1) Å. 2 crystallizes in the monoclinic space group P2₁/c with cell dimensions a = 11.156(3) Å, b = 8.417(2), c = 30.901(8) Å, and = 93.279°. In spite of the different cyclic systems, similar complexes are formed where the Hg atom is coordinated by two CN groups and six oxygen atoms of the crown ether. The structure of 1 is isostructural with the crystal structures of 18C6—HgCl₂, 18C6—CdBr₂, 18C6—Sr(BH₄)₂, and 18C6—Ba(BH₄)₂. Furthermore, 1 is very similar to other 18C6—HgX₂ complexes.