Neue Kupfertellurid‐Cluster – Synthesen,Kristallstrukturen und optische Spektren

New Coppertelluride Clusters – Syntheses, Crystal Structures, and Optical Spectra Reactions of copper(I) acetate with Te(SiMe₃)₂ lead in the presence of tertiary phophines PR₃ (R = organic group) to the formation of new coppertelluride clusters: Cu₈Te₄(PPh₃)₇] ( 1 ), Cu₁₆Te₉(PPh₃)₈] ( 2 ), Cu₂₃Te₁₃(PPh₃)₁₀] ( 3 ), Cu₄₄Te₂₃(PPh₃)₁₅] ( 4 ), Cu₁₂Te₆(PPh₃)₈] ( 5 ), Cu₂₆Te₁₂(PEt₂Ph)₁₂] ( 6 ), Cu₁₆Te₈(PⁿPr₂Ph)₁₀] ( 7 ), Cu₄₄Te₂₃(PⁿPr₂Ph)₁₅] ( 8 ), Cu₂₄Te₁₂(PⁱPr₃)₁₂] ( 9 ). Simple electron counting on the basis of Cu¹⁺ and Te^2– suggests that the smaller and medium size clusters 1 , 5 , 7 , and 9 are electron precise compounds and that on the other hand some of the medium size and larger ones 2 , 3 , 4 , and 8 must contain mixtures of Cu¹⁺/Cu²⁺ ions or 6 Cu¹⁺ ions and Cu⁰ atoms. UV‐VIS spectra in the solid state strongly confirms this suggestion by showing broad intervalence bands in the region of higher wavelengths for the cluster compounds formally being not electron precise. Apparently there is also an interesting dependence of these intervalence bands on the size of the cluster molecules.