Combining a Phenanthroline Moiety with Peralkylated Guanidine Residues: Homometallic Cu^II, Ni^II and Zn^II Halide Complexes with Site‐Differentiating Janus Head Ligands

Abstract

The unique core portion of Janus head pro-ligands based on a tailored phenanthroline-bis(guanidine) architecture has been utilized to generate a multiplicity of homometallic copper(II), nickel(II) and zinc(II) complexes terminated by halide constituents. The bis-bidentate nitrogen donor ligands provide coordination sites with metal-differentiating properties which can be loaded successively starting with the phenanthroline interface as can be demonstrated by mononuclear species which form under metal deficient conditions. Furthermore, depending on both the alkylation and metalation stage of the guanidine residues comprising variants with tetramethyl-, tetraethyl-, dimethylethylene-, and dipentylene-guanidino function- [a] 5177 molecular structures, which are presented in Scheme 2, were identified by crystal structure analysis or mass spectrometry (see crystal structures and experimental section). Scheme 2. Synthesized mononuclear copper(II) (1-4) and nickel(II) (5 and 6) complexes.