Composition and structure of the surface compounds formed after interaction between Cu(OH)2 supported on aerosil and bpy, py, PhOH, and H2O2 are studied. The EXAFS and electron spectroscopy methods show the main part of copper ions to remain in a hydroxide surrounding, whose structure does not change practically and does not depend on the nature of the extra ligands used. The colloidal Cu(OH)2 stabilized by starch is found to reveal the same properties as the supported one, but differs by greater sizes of hydroxide particles. Copyright 1999 Academic Press.