Kupferkomplexe des neuen Chelatliganden 1‐Methyl‐2‐(2‐thiophenolato)‐1H‐benzimidazol (mtpb) und dessen Oxidationsprodukten

Copper Complexes of the New Chelate Ligand 1‐Methyl‐2‐(2‐thiophenolato)‐1H‐benzimidazole (mtpb) and of its Oxidation Products Anodic electrolysis of copper in acetonitrile in the presence of Hmtpb leads to formation of yellow Cu₄(mtbp)₄] which was crystallized as a dichloromethane solvate with two crystallographically independent cluster molecules in the unit cell. The copper(I) atoms exhibit slightly pyramidal S₂N coordination with bridging thiolate sulfur atoms. The two clusters contain the four copper atoms arranged in a more (Cu1‐Cu4) or less (Cu5‐Cu8) distorted bisphenoidal arrangement. Reaction of mtpb^— with Cu(ClO₄)₂ under anoxic conditions also produces Cu₄(mtpb)₄]. However, the admittance of O₂ in the reaction of mtpb^— with copper(II) acetate in methanol causes oxidation of the sulfur atoms; a square‐pyramidal configurated copper(II) complex Cu(CH₃CO₂‐κ²O)(L₁‐κN)(L₂‐κN, O)] has been isolated and crystallographically characterized in which L₁ is the neutral sulfinic methyl ester and L₂^— is the sulfonate derived from mtpb^—.