Closed and open framework architectures in copper(II) complexes with triazine substituted N,N′-bis-pyridin-2-ylmethyl-ethane-1,2-diamine ligands

Both closed and open framework structures were designed for copper complexes with N,N′-bis-pyridin-2-ylmethyl-ethane-1,2-diamine (2-bpen)-based ligands. The design included substitution at the bridging aliphatic nitrogen atoms by reaction with cyanuric chloride to yield the 3,5-dichloro-2,4,6-triazine derivative. The chloride atoms on the triziane rings were further substituted by either electron donating amines, or an electron withdrawing thiomethyl moiety. The substitution of bridging nitrogen atoms by more electron donating aminated 2,4,6-triazines led to the formation of copper(II) complexes with closed square pyramidal architecture. On the other hand, substitution of bridging nitrogen atoms by the more electron withdrawing 2,4,6-triazines with thioether groups led to the formation of square planar or tetrahedral copper complexes with an open framework architecture whose specific structure and oxidation state depended on the anion.