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 (λmax=335 nm), singlet oxygen 1О2 (emission near 1270 nm) and its dimer (1О2)2 (λmax=490, 645, 715 nm). 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 (λmax=353 nm, 3.7 eV). 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.