Аннотация:Visible light irradiation of the readily available sandwich complex [(C5H5)Fe(C6H6)]BF4 with multidentate salicylate dyes such as Aluminone, Alumocresone, Chrome Azurol S, or Eriochrome Cyanine R produced intesively colored iron(III) complexes. Similar reaction can proceed on paper, cotton, or polyacrylamide hydrogel to give colored pH-sensitive patterns.