Synthesis, characterization and crystal structures of di-three-coordinated copper(I) macrocyclic Schiff base complexes

The air-stable di-copper(I) complexes Cu2L(SCN)2 (1) and Cu2L(SCN)1.86I0.14 (2) of the N4 macrocyclic Schiff base ligand L have been synthesized and characterized by IR, elemental analysis, UV–Vis and crystal structure determination. X-ray analysis of the complexes shows an approximate distorted trigonal planar geometry around each copper(I) ion that is constructed from one N-bonded thiocyanate (or iodide in 2) group and two imine nitrogen atoms. DFT calculations were used to determine the structural features of the Cu2L(SCN)2 complex, and these were consistent with the experimental data for the complex.

Synthesis, characterization and crystal structures of two di-three-coordinated copper(I) complexes of a 20-membered [2+2] macrocyclic Schiff base ligand with N4 donors, containing SCN− and I− groups have been investigated. Density functional theory calculations have also been carried out for one complex to determine its structural features, and these results were compared with the experimental data for the complex.Figure optionsDownload as PowerPoint slideResearch highlights
► Complexes bearing macrocyclic Schiff base with N4 donors and terminal SCN− and I−.
► Each Cu(I) atom is three coordinated in an approximate distortion trigonal planar.
► Replacement of I− with SCN− in Cu2LI2 does not happen in presence of excess KSCN.
► The observed geometry parameters are in good agreement with DFT calculations.