Studies of Some Cadmium(II) and Mercury(II) Complexes With Dicyclohexylphosphino-N-Phenylthioformamide, LH: Crystal and Molecular-Structures of [Cdl₂(LH)]₂, ([HgCl₂(LH)]₂.CH₂Cl₂) And HgCl₂(LH)₂

Abstract

The crystal and molecular structures of the title compounds, [CdI₂(LH)]₂, (1), [HgCl₂(LH)]₂.CH₂Cl₂(2), and HgCl₂(LH)₂(3)[where LH = dicyclohexylphosphino-N-phenyl-thioformamide,* (c-C₆H₁₁)₂PC(S)N(H)Ph] have been determined by single-crystal X-ray diffraction techniques. Crystals of (1) are monoclinic, space group P2₁/n, a 13.051(2), b 10.183(1), c 18.106(1)Ǻ and β 101.55(8)° with Z 2; R and R_w were 0.047 and 0.044 respectively for 2320 unique, observed reflections. The unit cell contains two equivalent centrosymmetric, halogen-bridged cadmium dimers. Crystals of (2) are triclinic, space group Pī, with a 10.668(4), b 14.978(3), c 16.838(4)Ǻ, and α 111.80(2), β 101.03(2), γ 92.06(2)° with Z 2; R and R_w were 0.069 and 0.067 respectively for 3379 unique observed reflections. The structure shows two independent centrosymmetric halogen-bridged dimers within the unit cell. Crystals of (3) are monoclinic, space group C2/c, a 24.719(6), b 12.247(3), c 26.818(6) Ǻ, and β 94.62(2)° with Z 8; R and R_w were 0.075 and 0.071 respectively for 2698 unique, observed reflections. The structure shows the complex to be monomeric.

In all three compounds the metal atom is in an approximately tetrahedral environment with the potentially multidentate ligand, LH, coordinating only through the phosphorus atom. The mercury compounds show a much larger deviation from ideal tetrahedral geometry than does the cadmium compound.