Synthesis of alkynyl(tricarbonyl)rhenium complexes containing a lightly coordinated diamine ligand

Several alkynyl(tricarbonyl)diaminerhenium complexes were prepared from corresponding halo complexes and silver acetylides. With the diamine N,N′-dimethylpiperazine the compounds were found to be sufficiently stable to allow synthetic transformations on the acetylide ligand as well as purification by chromatography and subsequent substitution of the diamine ligand by stronger ligands such as phenanthrolines or isocyanides.