Formation of singlet oxygen in the system tris(bipyridine)ruthenium(II)–dimethyldioxirane

Dioxiranes: from oxidative transformations to chemiluminescence

“…98 The following scheme was proposed to interpret the CL observed: }This should depend appreciably on the energy characteristics of the reaction. Thus we were unable to detect CL of singlet oxygen in the reaction of the dioxirane 1a with Ce(III), 17,343 apparently, due to the too high redox potential of the Ce(III)/Ce(IV) pair (1.4 V), 358 which precludes the transfer of an electron from Ce(III) to the dioxirane.…”

“…On the contrary, it is accompanied by very bright CL, which occurs in the infrared region (1270 nm), indicating the formation of singlet oxygen in the system. 17,343 The yield of 1 O 2 based on the decomposed dioxirane 1a in the Me 2 CO ± CD 3 CN (1 : 2) system is 0.03%. It is notable that the kinetics of the IR CL decay, unlike that for the Ru(II)* luminescence in the visible region of the spectrum, follows a fairly complex pattern (Fig.…”

“…10). 17,343 Thus, the Ru(II) ± 1a system contains two luminescence emitters, 15,17,343 Ru(II)* in the visible region and 1 O 2 in the infrared region. A possible pathway to 1 O 2 is the reaction of Ru(II) with the dioxirane 1a by the electron chain mechanism (Scheme 13, pathways b and c).…”

“…Luminescence in the visible region might be due to the dimol emission of 1 O 2 (634 and 703 nm). 286 Scheme 14 Finally, the third example of evolution of 1 O 2 in the reactions of dioxiranes, namely, in the decomposition of 1a catalysed by the complex Ru(bipy) 3 Cl 2 17 was considered in detail above.…”

“…13 C NMR spectra were recorded relative to Me4Si. b Acetone labelled by the17 O-isotope was used as the initial ketone. c The measurements were performed in 1,1,1-trifluoropropanone.…”