Unexpectedly ambivalent O-2 role in the autocatalytic photooxidation of 2-methoxybenzyl alcohol in water

Leonardo Palmisano, Vincenzo Augugliaro, Andrea Pace, Vittorio Loddo, Sedat Yurdakal, Bilge Sina Tek, Giovanni Palmisano

Risultato della ricerca: Article

5 Citazioni (Scopus)

Abstract

tAn unusual autocatalytic photooxidation of 2-methoxybenzyl alcohol has been observed under UV irradi-ation in aqueous medium. The homogeneous oxidation is catalyzed by the corresponding aldehyde that isalso the main oxidation product. The trend of alcohol disappearance rate matches the typical shape of anautocatalytic process, where a crucial and ambivalent role is played by the presence of molecular oxygen.Low oxygen concentrations give rise to a zero-order reaction since the beginning of irradiation, whilehigher amounts of oxygen reduce the alcohol oxidation rate until the aldehyde reaches a concentrationhigh enough to speed up the alcohol’s conversion. Experiments performed by varying alcohol, aldehydeand oxygen concentrations in both aqueous and organic media suggest that the alcohol oxidation is ini-tially favored by the presence of oxygen. Once the formed aldehyde competes for photon absorption,the oxidation is driven by aldehydes alpha cleavage leading to reactive oxygenated species in aqueousmedium. An excess of oxygen quenches the latter processes thus inhibiting/slowing down the reaction.
Lingua originaleEnglish
pagine (da-a)37-42
Numero di pagine6
RivistaJOURNAL OF MOLECULAR CATALYSIS. A: CHEMICAL
Volume403
Stato di pubblicazionePublished - 2015

Fingerprint

Photooxidation
photooxidation
alcohols
Alcohols
Aldehydes
aldehydes
Water
Oxygen
oxygen
Oxidation
oxidation
water
Molecular oxygen
cleavage
Photons
Irradiation
trends
irradiation
photons
products

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Process Chemistry and Technology
  • Physical and Theoretical Chemistry

Cita questo

@article{b2d935efcbf44895882b057963f98c28,
title = "Unexpectedly ambivalent O-2 role in the autocatalytic photooxidation of 2-methoxybenzyl alcohol in water",
abstract = "tAn unusual autocatalytic photooxidation of 2-methoxybenzyl alcohol has been observed under UV irradi-ation in aqueous medium. The homogeneous oxidation is catalyzed by the corresponding aldehyde that isalso the main oxidation product. The trend of alcohol disappearance rate matches the typical shape of anautocatalytic process, where a crucial and ambivalent role is played by the presence of molecular oxygen.Low oxygen concentrations give rise to a zero-order reaction since the beginning of irradiation, whilehigher amounts of oxygen reduce the alcohol oxidation rate until the aldehyde reaches a concentrationhigh enough to speed up the alcohol’s conversion. Experiments performed by varying alcohol, aldehydeand oxygen concentrations in both aqueous and organic media suggest that the alcohol oxidation is ini-tially favored by the presence of oxygen. Once the formed aldehyde competes for photon absorption,the oxidation is driven by aldehydes alpha cleavage leading to reactive oxygenated species in aqueousmedium. An excess of oxygen quenches the latter processes thus inhibiting/slowing down the reaction.",
keywords = "2-Methoxybenzaldehyd, 2-Methoxybenzyl alcohol, Autocatalytic photooxidation, Homogeneous photocatalysis, O2 quenching",
author = "Leonardo Palmisano and Vincenzo Augugliaro and Andrea Pace and Vittorio Loddo and Sedat Yurdakal and Tek, {Bilge Sina} and Giovanni Palmisano",
year = "2015",
language = "English",
volume = "403",
pages = "37--42",
journal = "Journal of Molecular Catalysis A: Chemical",
issn = "1381-1169",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Unexpectedly ambivalent O-2 role in the autocatalytic photooxidation of 2-methoxybenzyl alcohol in water

AU - Palmisano, Leonardo

AU - Augugliaro, Vincenzo

AU - Pace, Andrea

AU - Loddo, Vittorio

AU - Yurdakal, Sedat

AU - Tek, Bilge Sina

AU - Palmisano, Giovanni

PY - 2015

Y1 - 2015

N2 - tAn unusual autocatalytic photooxidation of 2-methoxybenzyl alcohol has been observed under UV irradi-ation in aqueous medium. The homogeneous oxidation is catalyzed by the corresponding aldehyde that isalso the main oxidation product. The trend of alcohol disappearance rate matches the typical shape of anautocatalytic process, where a crucial and ambivalent role is played by the presence of molecular oxygen.Low oxygen concentrations give rise to a zero-order reaction since the beginning of irradiation, whilehigher amounts of oxygen reduce the alcohol oxidation rate until the aldehyde reaches a concentrationhigh enough to speed up the alcohol’s conversion. Experiments performed by varying alcohol, aldehydeand oxygen concentrations in both aqueous and organic media suggest that the alcohol oxidation is ini-tially favored by the presence of oxygen. Once the formed aldehyde competes for photon absorption,the oxidation is driven by aldehydes alpha cleavage leading to reactive oxygenated species in aqueousmedium. An excess of oxygen quenches the latter processes thus inhibiting/slowing down the reaction.

AB - tAn unusual autocatalytic photooxidation of 2-methoxybenzyl alcohol has been observed under UV irradi-ation in aqueous medium. The homogeneous oxidation is catalyzed by the corresponding aldehyde that isalso the main oxidation product. The trend of alcohol disappearance rate matches the typical shape of anautocatalytic process, where a crucial and ambivalent role is played by the presence of molecular oxygen.Low oxygen concentrations give rise to a zero-order reaction since the beginning of irradiation, whilehigher amounts of oxygen reduce the alcohol oxidation rate until the aldehyde reaches a concentrationhigh enough to speed up the alcohol’s conversion. Experiments performed by varying alcohol, aldehydeand oxygen concentrations in both aqueous and organic media suggest that the alcohol oxidation is ini-tially favored by the presence of oxygen. Once the formed aldehyde competes for photon absorption,the oxidation is driven by aldehydes alpha cleavage leading to reactive oxygenated species in aqueousmedium. An excess of oxygen quenches the latter processes thus inhibiting/slowing down the reaction.

KW - 2-Methoxybenzaldehyd

KW - 2-Methoxybenzyl alcohol

KW - Autocatalytic photooxidation

KW - Homogeneous photocatalysis

KW - O2 quenching

UR - http://hdl.handle.net/10447/176159

M3 - Article

VL - 403

SP - 37

EP - 42

JO - Journal of Molecular Catalysis A: Chemical

JF - Journal of Molecular Catalysis A: Chemical

SN - 1381-1169

ER -