Paramagnetic Cu II complexes with 1-(hetarylmethyl)silatranes

The structures of paramagnetic complexes CuCl 2 •L with L = HetCH 2 Si(OCH 2 CH 2 ) 3 N [Het = pyrrol-1-yl ( 1 ), indol-1-yl ( 2 ), carbazol-9-yl ( 3 ), imidazole-1-yl ( 4 ), 3,5-dimethylpyrazol-1-yl ( 5 ), 1,2,4-triazol-1-yl ( 6 ), benzimidazol-1-yl ( 7 ), and 1,2,3-benzotriazol-1-yl ( 8 )] were studied by the ESR and quantum chemical methods in terms of the density functional theory (DFT) approximation. The difference in structures of complexes CuCl 2 •1—CuCl 2 •8 is mainly determined by the nature of the five-membered heterocycle. The ESR spectra at room temperature are typical of the mononuclear complexes of Cu II of axial symmetry with various types of distortions. In complexes CuCl 2 •1—CuCl 2 •3, narrow symmetric signals of zero-valent copper are recorded. These signals remain in the spectra for at least six months, which can characterize them as efficient stabilizing matrices of nanoparticles.