The first example of generation and emission of divalent Sm2+* ion in a liquid-phase chemiluminescence in the system SmCl3·6H2O–THF–Bui2AlH–O2

Abstract

Abstract First it was found that the divalent Sm 2+ ion can act as enhancer and emitter of a liquid-phase chemiluminescence (СL) on the example of the near-infrared emission of Sm 2+* in the system SmCl 3 ·6H 2 O–THF–Bu i 2 AlH–O 2 . The Sm 2+* –CL ( λ max = 780 ± 20 nm) occurs upon adding the diisobutylaluminum hydride Bu i 2 AlH to a suspension of the SmCl 3 ·6H 2 O crystalline hydrate in THF. The Bu i 2 AlH removes water molecules from the coordination sphere of Sm 3+ and reduces Sm 3+ to Sm 2+ with formation of the SmCl 2 ·(THF) 2 complex. The excess of Bu i 2 AlH is oxidized by oxygen with generating a primary emitter, the triplet-excited molecule of isobutyric aldehyde 3 Me 2 CHC(H) = O * . The energy of the latter is transferred to the SmCl 2 ·(THF) 2 complex, leading to the formation of the excited state of the Sm 2+ ion. The composition of SmCl 2 ·(THF) 2 complex, which are formed after the interaction in the system SmCl 3 ·6H 2 O–THF–Bu i 2 AlH–O 2 , was also determined. Moreover, its photoluminescence (PL), UV–vis IR, 1 H and 13 C NMR spectra were measured. The spectrum of Sm 2+* –CL contains maxima both ions Sm 2+ and Sm 3+ due to incomplete reducing of Sm 3+ .