Structural Variety of Cobalt(II), Nickel(II), Zinc(II), and Cadmium(II) Complexes with 4,4'-Azopyridine: Synthesis, Structure and Luminescence Properties.

Self-assembled bi- and polymetallic complexes of Co(II), Ni(II), Zn(II), and Cd(II) were obtained by the reaction of 4,4'-azopyridine (azpy) with metal tri-tert-butoxysilanethiolates (Co, 1; Cd, 2), acetylacetonates (Ni, 3; Zn, 4), and acetates (Cd, 5). All compounds were characterized by single-crystal X-ray structure analysis, elemental analysis, FTIR spectroscopy, and thermogravimetry. Complexes 1, 2 and 4, 5 exhibit diverse structural conformations: 1 is bimetallic, 2 and 4 are 1D coordination polymers, and 5 is a 2D coordination framework formed from bimetallic units. The obtained complexes contain metal atoms bridged by a molecule of azpy. The luminescent properties of 1-5 were investigated in the solid state.