Synthesis, Properties, and Molecular and Crystal Structures of (Me4N)4 (E = S, Se; M = Zn, Cd): Molecular Supertetrahedral Fragments of the Cubic Metal Chalcogenide Lattice

Article abstract of DOI:10.1021/ja00333a030

The complexes ^4-(Me4N⁺) (3M, M = Zn, Cd) and ^4-(Me4N⁺) (4M, M = Zn, Cd) are formed in 80-100percent yield by the reactions of sulfur or selenium with the adamantanoid cages ^2-(Me4N⁺) (2M, M = Zn, Cd).Complexes 3M and 4M do not degrade to the metal chalcogenides, which also are not formed in the preparative reactions under varied conditions.All four complexes 3M and 4M are molecular, with the same (μ₃-E)4M10S16 (E = S, Se) core structure, which is a supertetrahedral fragment of the cubic (sphalerite) ME lattice.In terms of expanding polyhedra the molecular structure is octahedro-M₆-tetrahedro-(μ₃-E)4-truncated tetrahedro-(μ-SPh)12-tetrahedro-M4-tetrahedro-(SR)4, with <(μ₃-E)2(μ-SPh)2> coordination at the six inner metal atoms and <(μ-SPh)3(SPh)> coordination at the four outer metal atoms.The three-coordinate chalcogenide ions are located at the centers of the hexagonal faces of the (μ-S)12 truncated tetrahedron.By inversion at the sulfur atoms of the 12 bridging thiolate ligands, 186 molecular configurational isomers can occur.Three different crystal structure determinations of 3M (one Zn, two Cd) have revealed the occurence of two isomers with 4 molecular symmetry.Crystal structure A (M = Cd), space group I4, contains one isomer, while the other isomer occurs in crystal structure B (M = Zn), space group P42₁c, and crystal structure C (M = Cd), space group I42m, which is a mirror disordered form of structure B.Small distortions of the core geometry from idealized 43m (T_d) symmetry can be traced to weak repulsions between the phenyl substituents on the surfaces of the molecular anions.Low-frequency infrared and Raman data for 2M, 3M, 4M, and (Me4N)2 are interpreted empirically.Crystal data for A: I4 a = 20.946 (2) Angstroem, c = 14.779 (2) Angstroem, Z = 2(xC112H128Cd10S20N4), 2971 reflections (I> 3?(I)), Cu Kα, R (R_w) = 0.033 (0.045).B: P42₁c, a = 19.783 (4) Angstroem, c = 16.871 (5) Angstroem, Z = 2(x C112H128Zn10S20N4), 1140 reflections, Mo Kα, R (R_w) = 0.044 (0.054).C: I42m, a = 20.140 (2) Angstroem, c = 16.896 (1) Angstroem, Z = 2(x C112H128Cd10S20N4), 916 reflections, Mo Kα, R (R_w) = 0.042 (0.051).