6533b7cffe1ef96bd1257c4d

RESEARCH PRODUCT

Azoxybenzene rearrangement catalyzed by solid acids

Gabriela DyrdaMałgorzata A. BrodaAndrzej A. DomańskiRudolf Słota

subject

Steric effectsHeterogeneous catalysisZeoliteAzo compoundProcess Chemistry and TechnologyDFT calculationsWallach rearrangementHeterogeneous catalysisCatalysisCatalysischemistry.chemical_compoundchemistryComputational chemistryYield (chemistry)Azoxybenzene rearrangementPolymer chemistryPolystyrenePhysical and Theoretical ChemistryZeoliteSulfonated polystyrene resin

description

Abstract For the first time, the potential of acidic cation-exchange resin (sulfonated polystyrene) to catalyze the Wallach rearrangement of azoxybenzene into 4-hydroxyazobenzene has been proved. This finding reveals an alternative reaction path possible in a heterogeneous process using solid acids and may help to clear some doubts concerning the rearrangement mechanism postulated so far. The resin-induced reaction was found to proceed exclusively in a non-polar medium. Reasonable yield was obtained particularly in isooctane due to favorable distribution of azoxybenzene throughout the resin's matrix. On the contrary, the HY type zeolite did not activate the rearrangement, most probably because of steric hindrance. Experimental results favor the hypothesis of a quinoid intermediate controlling the chemistry of azoxybenzene conversion, which also follows from thermodynamic considerations involving DFT calculations.

yearjournalcountryeditionlanguage
2008-09-01Journal of Molecular Catalysis A: Chemical
https://doi.org/10.1016/j.molcata.2008.05.016