DFT studies of copper complexes with biphenyldiimino dithioether

Using DFT method, the optimized geometries of tetrahedral and square-planar complexes of Cu(I) and Cu(II) with tetrabenz[a,e,g,k]-15,18-dithia-9,24-diaza-cyclohexadeca-9,23-diene macrocyclic ligand (bite) have been investigated and compared with experimental data. The non-equivalence of Cu-S bonds in tetrahedral Cu(bite)+ is caused by mechanical strain of the bite ligand and may be significantly influenced by crystal packing. The energy and electronic structure of Cu(bite)+/2+ complexes indicates that the mechanical strain of the bite ligand should play the key role in electron transfer processes.