Lanthanide and heterometallic chalcogenido clusters

Lanthanide ions form stable chalcogen rich clusters, the structures of which are dependent on the size of the lanthanide ion, the identity of the ancillary ligand and the basicity of the solvent.; Smaller lanthanides form selenium rich tetramers in strong and weak Lewis base solvents. The group of clusters (THF)₆Ln₄I ₂(SeSe)₄(μ₄-Se) (Ln = Yb, Tm, Er, and Ho) have been isolated from less basic THF. From more basic pyridine three Yb clusters with different EPh (E = S, Se, Te) chalcogenolate ligands were obtained. Their structures are dependent on the electronegativity of the chalcogenolate ligands. In this series the previously unknown SeTePh ligand was first obtained. All Yb compounds are deep red and their visible properties are dominated by LMCT absorptions.; Larger lanthanides produce selenium rich clusters (py)₁₁Ln ₇(μ₅-Se)₂(μ₃-Se)(μ₂-Se ₂)₅(μ₃-Se₂)(μ₄-Se ₃)₂Hg(SePh) (Ln = Ce, Nd, Pr) in pyridine. All are deep orange because of an electronic transition localized on the diselenido units. The thermolysis of Ln₇ compounds are identified as two solid state phases: Ln₃Se₄ and Ln₂Se₃.; The basicity of solvents influences the nuclearity of the cluster compounds. The largest soluble heterochalcogenido cluster (THF)₁₄Ln₁₀ (μ₄-S)₆(μ₂-SeSe)₆I ₆ (Ln = Ho, Er, Dy) was obtained in THF. The structure of the middle core, Ln₆S₆ is similar to a structure of (THF) ₆Er₆S₆I₆ compound, with slight distortion. The Ln-S bond lengths in both compounds show trans effects, which points to some degree of covalency in Ln-E ionic bonding. Both Er₁₀ and Er ₆ clusters exhibit Er emission at 1543 nm. When Er₁₀ cluster dissolved in pyridine, (py)₆Er₂(Se_0.2S _0.8)(SeSe) was formed. This dimer contains the fist μ-E2− ligand in chalcogenido cluster chemistry.; The first group of stable lanthanide/group 12 metal selenido clusters (py)₈Ln₄M₂Se₆(SePh)₄ (Ln = Yb, Er, Lu; M = Hg, Cd) was isolated from pyridine. X-ray analysis showed that all of the compounds have doublecubane structures. Er emission at 1543 nm in (py)₈Er₄Cd₂Se₆(SePh) ₄ is more intense than in (py)₈Er₄Hg₂Se ₆(SePh)₄. The thermolysis products of the two Cd clusters were identified as the known solid state materials Yb₂CdSe ₄ and Er₂CdSe₄.