Tetragonal Distortion in Thermochromic Copper(II) Diamine Complex Induced by the Fixation on Silica Surfaces and Their Catalytic Investigations

The fixation of the thermochromic complex [Cu(dieten)(2)](ClO4)(2) on the silica surfaces induced the transformation from a square-planar to tetrahedral coordination geometry around the copper atoms along with the color changes from red violet to pale blue. Hybrid materials were found to be catalytically active toward the oxidation of benzene to phenol using hydrogen peroxide as an oxidant, while the pure complex remained virtually inactive.