Spectroscopic study of ternary copper(II) complexes on a silica surface

The formation of ternary surface complexes of copper(II) with one or two molecules of 2,2′-bipyridine (bpy) or α-picolinic acid (Hpic), which were obtained after adsorption on the silica surface in different ways, was studied by electronic and ESR spectroscopy. Coordination of the ligands, which were preliminarily adsorbed by copper ions, afforded only 1∶1 ternary surface complexes. In both cases, coordinatively more saturated ternary surface complexes were formed only when Cu(bpy)₂ ²⁺ and Cu(pic)₂ were adsorbed on the SiO₂ surface from solutions. The compositions and structures of the ternary surface complexes containing bipyridine ligands are temperature independent, whereas in the picolinate-containing ternary surface complexes, the coordination spheres of the adsorbed complexes are rearranged as the temperature changes. Presented at the First Moscow Workshop on Highly Organized Catalytic Systems (June 19, 1997). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1765–1771, October, 1997.