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

Copper Complexes of the New Chelate Ligand 1‐Methyl‐2‐(2‐thiophenolato)‐1 H ‐benzimidazole (mtpb) and of its Oxidation Products Anodic electrolysis of copper in acetonitrile in the presence of Hmtpb leads to formation of yellow [Cu 4 (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 S 2 N 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(ClO 4 ) 2 under anoxic conditions also produces [Cu 4 (mtpb) 4 ]. However, the admittance of O 2 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(CH 3 CO 2 ‐κ 2 O)(L 1 ‐κN)(L 2 ‐κN, O)] has been isolated and crystallographically characterized in which L 1 is the neutral sulfinic methyl ester and L 2 — is the sulfonate derived from mtpb — .