Syntheses, Characterization, and Crystal Structures of a Pair of Thiocyanate‐bridged Polynuclear Schiff Base Copper(II) Complexes

A pair of novel thiocyanate‐bridged polynuclear Schiff base copper(II) complexes, [CuL1(NCS)]_n · nClO₄ (1) and [Cu₂(L2)₂(NCS)₂] · 2ClO₄ (2) (L1=N‐isopropyl‐N′‐(1‐pyridin‐2‐ylmethylidene)ethane‐1,2‐diamine, L2=N,N‐dimethyl‐N′‐(1‐pyridin‐2‐ylmethylidene)ethane‐1,2‐diamine), have been synthesized and characterized by elemental analysis, IR spectrum and single crystal X‐ray diffraction. Each Cu atom in (1) and (2) is five‐coordinate in a square‐pyramidal configuration, with three N atoms of one Schiff base ligand and one terminal N atom of a bridging thiocyanate ligand defining the basal plane, and one terminal S atom of another bridging thiocyanate ligand occupying the apical position. In (1), the [N‐isopropyl‐N′‐(1‐pyridin‐2‐ylmethylidene)ethane‐1,2‐diamino]copper(II) units are linked by the bridging thiocyanate ligands, forming polymeric chains. In (2), adjacent two [N,N‐dimethyl‐N′‐(1‐pyridin‐2‐ylmethylidene)ethane‐1,2‐diamino]copper(II) units are linked by two bridging thiocyanate ligands, forming dimmers.

Keywords:

• synthesis
• crystal structure
• Schiff base
• copper complex
• polynuclear complex