7325-63-5Relevant academic research and scientific papers
Equilibrium between 2-oxomorpholin-3-yl radicals and viologen radicals. Determination of reduction potentials
Mahoney, Robert Patrick,Fretwell, Paul A.,Demirdji, Samuel H.,Mauldin III,Benson Jr., Olester,Koch, Tad H.
, p. 186 - 193 (2007/10/02)
Bi(3,5,5-trimethyl-2-oxomorpholin-3-yl) (TM-3 dimer) undergoes bond homolysis to yield 3,5,5-trimethyl-2-oxomorpholin-3-yl (TM-3), which reduces propyldiquat (PDQ2+) to its radical cation PDQ+. The byproduct is 5,6-dihydro-3,5,5-trimethyl-1,4-oxazin-2-one (8). Similarly, bi(5,5-dimethyl-4-ethyl-2-oxomorpholin-3-yl) (DEM-3 dimer) cleaves to 5,5-dimethyl-4-ethyl-2-oxomorpholin-3-yl (DEM-3), which reduces paraquat (PQ2+) to its radical cation PQ+. The byproduct, 5,5-dimethyl-4-ethyl-3-methoxy-2-oxomorpholine (10), results from rapid addition of methanol solvent to the transient 5,6-dihydro-4-ethyl-5,5-dimethyl-1,4-oxazin-2-onium cation (11). Concentration versus time data for the respective viologen radical cations together with reduction potentials for the viologens place the reduction potentials for TM-3 dimer and DEM-3 dimer at -0.56 and -0.33 V versus NHE, respectively, in Tris/Tris·H+ buffered methanol. The kinetics of reduction are analyzed using numerical integration, and the two reducing agents are compared with dithionite.
