Copper(I) complexes of N-centered aliphatic tripodal trithioether ligands – Adjustment of complex geometry by variation of spacer lengths

A series of novel aliphatic tripodal trithioether ligands 4–6 differing in the lengths of the alkyl chains between central nitrogen atom and sulfur donor function has been synthesized. The neutral ligands 4–6 react with copper(I) under formation of the mononuclear complexes 7–9 featuring exclusive coordination of the metal center by the tertiary amine and the three thioether donor functions of the tripodal ligand. Molecular structures of 7 and 9 show a direct influence of the spacer lengths between central and terminal donor functions on the geometry of the tetracoordinated complex cations. Substitution of one ethylene by a propylene spacer leads to a larger bite angle between the amine and thioether donor functions and effects a tetrahedral distortion for the complex cation in 7. For the copper(I) compound 9 with a ligand possessing exclusively propylene spacers this effect is increased leading to a tetrahedral geometry of the complex cation.