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 new mixed valence copper(II)–copper(I) complexes, [Cu(L 1 ) 2 CuI 3 ] ( 1 ) and [Cu(L 2 ) 2 ] 2 [Cu(L 2 ) 2 (Cu 2 I 5 ) 2 ]·2CH 3 CN ( 2 ) where L 1 = N,N-dimethylethane-1,2-diamine and L 2 = 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. [ABSTRACT FROM AUTHOR]