Theoretical study on the degree of delocalization of unpaired spin in two mixed valence copper(II/I) complexes with isomeric chelating diamines and iodide

• Two mixed valence copper(II)–copper(I) complexes have been prepared by the in situ partial reduction of copper(II) with iodide.
• Both complexes have been characterized by elemental and spectral analysis and single crystal X-ray diffraction studies.
• Copper(I) centers have trigonal planar geometry in complex 1.
• Copper(I) centers have face-sharing tetrahedral geometry in complex 2.

Two new mixed valence copper(II)–copper(I) complexes, [Cu(L1)2CuI3] (1) and [Cu(L2)2]2 [Cu(L2)2(Cu2I5)2]·2CH3CN (2) where L1 = N,N-dimethylethane-1,2-diamine and L2 = N-ethylethane-1,2-diamine, have been synthesized using isomeric chelating diamines and iodide. Complexes are characterized by elemental analyses, IR and UV–Vis spectroscopy. Single crystal X-ray diffraction studies confirm their structures. The degree of delocalization of the unpaired spin has been investigated by computing the spin density using the crystallographic coordinates. Interestingly, it can be observed from that the unpaired electron is delocalized between both copper centers in complex 1, whereas complex 2 is a completely localized mixed valence complex.

Two new mixed valence copper(II)–copper(I) ​complexes have been synthesized and characterized by elemental analyses, IR and UV–Vis spectroscopy. Single crystal X-ray diffraction studies confirm their structures. Both complexes show hydrogen bonding interactions. The spin density plots of both complexes have been computed using the crystallographic coordinates, in order to investigate if they are completely valence localized, or they show some degree of delocalization of the unpaired spin.Figure optionsDownload as PowerPoint slide