Design of Wall-Functionalized Hybrid Silicas Containing Diazene Radical Precursors. EPR Investigation of Their Photolysis and Thermolysis

Stéphane Gastaldi (1) , Emily Bloch (2) , Eric Besson (1) , François Vibert (1) , Michèle P Bertrand (1) , Sylvain R.A. Marque (1) , Séverine Queyroy (1)

1 ICR - Institut de Chimie Radicalaire
2 MADIREL - Matériaux divisés, interfaces, réactivité, électrochimie

Bis-silylated diazenes were designed to prepare wall-functionalized hybrid silicas via the sol–gel process. These precursors enabled the straightforward generation of arylsulfanyl radicals by either photolysis or thermolysis. Their location in the framework of the mesoporous materials was evidenced by spin trapping experiments. The incidence of confinement on the radical lifetime was investigated by electron paramagnetic resonance (EPR). An amazing persistence (t1/2 = 27 min) was recorded at 473 K.

Keywords: thermal fragmentation; hybrid materials; sulfanyl radicals; radical persistence

Domains: Chemical Sciences; Organic chemistry; Chemical Sciences; Material chemistry

Stéphane Gastaldi, Emily Bloch, Eric Besson, François Vibert, Michèle P Bertrand, et al.. Design of Wall-Functionalized Hybrid Silicas Containing Diazene Radical Precursors. EPR Investigation of Their Photolysis and Thermolysis. Journal of Physical Chemistry C, 2015, 119 (10), pp.5434-5439. ⟨10.1021/jp5117382⟩. ⟨hal-01139937⟩