Chemiluminescence of the Ce3+* ions, and the 1О2 and (1О2)2 molecular species of oxygen induced by active surface of the (NH4)2Ce(NO3)6 crystals at reduction of Ce4+ to Ce3+ by water in heterogeneous system «(NH4)2Ce(NO3)6-C6H6-H2O»

We have discovered an unusual new chemiluminescence (CL) in the title system, which is different from other known CL by unusual combination of various in nature emitters, namely, electronically excited state of the Ce³⁺* ion (λ_max=335nm), singlet oxygen ¹О₂ (emission near 1270nm) and its dimer (¹О₂)₂ (λ_max=490, 645, 715nm). The Ce³⁺* ions and oxygen emitters ¹О₂ and (¹О₂)₂ are generated in the reaction of Ce⁴⁺ with water and hydrogen peroxide, respectively. CL is generated only in a heterogeneous system «(NH₄)₂Ce(NO₃)₆-C₆H₆-H₂O» and completely absent in a homogeneous solution (NH₄)₂Ce(NO₃)₆ in water containing benzene. This is due to the fact that the redox processes and CL in the «(NH₄)₂Ce(NO₃)₆-C₆H₆-H₂O» system are induced by active surface of the (NH₄)₂Ce(NO₃)₆ crystals. It is through the action of the active surface of the (NH₄)₂Ce(NO₃)₆ crystals is carried out population of such a high energy level of 5d¹ excited state of Ce³⁺* ion (λ_max=353nm, 3.7eV). Discovered CL is the first example of an experimental registration of the Ce³⁺* ion emission in a chemical reaction, because formation of Ce³⁺* ion previously assumed to be in a great many works on the study of CL in reactions of Ce⁴⁺ compounds with various reducing agents, including the reaction with water, initiated by light or catalysts. Possible mechanism generation of new CL in the system under study has been proposed in the paper.