Metallorganische Verbindungen des Kupfers: XIV Spaltung der Halogeno-Brücken in den zweikernigen Alkin-Kupfer(I)-Komplexen [CuX( η2-tmtch)] 2 (X=Cl, Br, I; tmtch=3,3,6,6-Tetramethyl-1-thia-4-cycloheptin) durch die N-haltigen Lewis-Basen Ammoniak, Anilin, Pyridin und Diethylamin

Abstract

The dinuclear alkyne copper(I)–halide complexes [CuX(tmtch)] 2 [tmtch=3,3,6,6-tetramethyl-l-thiacyclohept-4-yne; X=Cl ( 2a), X=Br ( 2b), X=I ( 2c)] react with the N containing Lewis bases ammonia, aniline, pyridine, and diethylamine to form the mononuclear compounds [CuX(N-base)(tmtch)] ( 5a: X=Cl, base=ammonia; 5b: X=Cl, base=aniline; 5c: X=Cl, base=pyridine; 5d: X=Cl, base=diethylamine; 5e: X=Br, base=diethylamine; 5f: X=I, base=diethylamine). X-ray diffraction studies on all compounds (except 5b) reveal trigonal-planar coordinated mononuclear Cu(I) complexes with the CC triple bond (123.7 pm) in the coordination plane. A strong Cu(I) alkyne interaction with two slightly different CuC bond lengths is found: a shorter distance (194.0 pm) to the carbon atom in trans position to the N base and a longer one (195.7 pm) to the carbon atom in trans position to the halide ligand.