Thermochemiluminescent peroxide crystals

Stefan Schramm,James Weston,Luca Catalano,Ejaz Ahmed,Durga Prasad Karothu,Taro Moriwaki,Liang Li,Panče Naumov,Nathan M Lui,Patrick Commins,Kyril M Solntsev

doi:10.1038/s41467-019-08816-8

Abstract

Chemiluminescence, a process of transduction of energy stored within chemical bonds of ground-state reactants into light via high-energy excited intermediates, is known in solution, but has remained undetected in macroscopic crystalline solids. By detecting thermally induced chemiluminescence from centimeter-size crystals of an organic peroxide here we demonstrate direct transduction of heat into light by thermochemiluminescence of bulk crystals. Heating of crystals of lophine hydroperoxide to ~115 °C results in detectable emission of blue-green light with maximum at 530 nm with low chemiluminescent quantum yield [(2.1 ± 0.1) × 10‒7 E mol‒1]. Spectral comparison of the thermochemiluminescence in the solid state and in solution revealed that the solid-state thermochemiluminescence of lophine peroxide is due to emission from deprotonated lophine. With selected 1,2-dioxetane, endoperoxide and aroyl peroxide we also establish that the thermochemiluminescence is common for crystalline peroxides, with the color of the emitted light varying from blue to green to red.

Highlights

Chemiluminescence, a process of transduction of energy stored within chemical bonds of ground-state reactants into light via high-energy excited intermediates, is known in solution, but has remained undetected in macroscopic crystalline solids
We demonstrate that the solid-state thermochemiluminescence is not limited to LHP but is common for cyclic, endo, and aroyl peroxides, and the color and spectrum of the emitted light are specific to the respective decomposition products
LHP was synthesized by Schenck-ene photooxygenation of lophine at −10 °C in presence of methylene blue adsorbed onto silica as a sensitizer in a custom-built LED photoreactor

Summary

Introduction

Chemiluminescence, a process of transduction of energy stored within chemical bonds of ground-state reactants into light via high-energy excited intermediates, is known in solution, but has remained undetected in macroscopic crystalline solids. The high-energy reaction intermediates are usually thermally labile hydroperoxides, 1,2dioxetanes, 1,2-dioxetaneones (1,2-dioxetanones), or 1,2-dioxetanedione[2,3,4] If these chemiluminophores are chemically modified to be stable at room temperature, their decomposition can be induced by heating or by application of mechanical force, and the respective phenomena are referred to as thermo- and mechanochemiluminescence. We demonstrate that the solid-state thermochemiluminescence is not limited to LHP but is common for cyclic, endo, and aroyl peroxides, and the color and spectrum of the emitted light are specific to the respective decomposition products. These results open prospects for application of organic peroxides as multicolor thermally sensitive solid light-emitting materials

Methods

Results

Conclusion