The 2750-Å electronic band system of phenol

Bist, H. D.; Brand, J. C. D.; Williams, Denis R.

doi:10.1016/0022-2852(66)90123-8

Cited by 108 publications

(17 citation statements)

References 19 publications

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“…We would like to acknowledge support from U.S. REMPI process. The laser scanned over the known [104][105][106] phenol resonance, Fig. 3) verify that this m/z 94 feature is C 6 H 5 OH.…”

Section: Acknowledgementsmentioning

confidence: 79%

Thermal Decompositions of the Lignin Model Compounds: Salicylaldehyde and Catechol

et al. 2018

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The nascent steps in the pyrolysis of the lignin components salicylaldehyde ( o-HOCHCHO) and catechol ( o-HOCHOH) were studied in a set of heated microreactors. The microreactors are small (roughly 1 mm ID × 3 cm long); transit times through the reactors are about 100 μs. Temperatures in the microreactors can be as high as 1600 K, and pressures are typically a few hundred torr. The products of pyrolysis are identified by a combination of photoionization mass spectrometry, photoelectron photoion concidence mass spectroscopy, and matrix isolation infrared spectroscopy. The main pathway by which salicylaldehyde decomposes is a concerted fragmentation: o-HOCHCHO (+ M) → H + CO + CH═C═O (fulveneketene). At temperatures above 1300 K, fulveneketene loses CO to yield a mixture of HC≡C-C≡C-CH, HC≡C-CH-C≡CH, and HC≡C-CH═C═CH. These alkynes decompose to a mixture of radicals (HC≡C-C≡C-CH and HC≡C-CH-C≡CH) and H atoms. H-atom chain reactions convert salicylaldehyde to phenol: o-HOCHCHO + H → CHOH + CO + H. Catechol has similar chemistry to salicylaldehyde. Electrocyclic fragmentation produces water and fulveneketene: o-HOCHOH (+ M) → HO + CH═C═O. These findings have implications for the pyrolysis of lignin itself.

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“…We would like to acknowledge support from U.S. REMPI process. The laser scanned over the known [104][105][106] phenol resonance, Fig. 3) verify that this m/z 94 feature is C 6 H 5 OH.…”

Section: Acknowledgementsmentioning

confidence: 79%

Thermal Decompositions of the Lignin Model Compounds: Salicylaldehyde and Catechol

et al. 2018

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“…It is essential to extend our theoretical models to such systems in order to understand the impact of this increasing complexity. The dissociation of phenol (C 6 H 5 OH) with 33 internal DOFs is a particularly intriguing problem with implications for photochemistry of cyclic moieties in amino acids. ,, Consequently it has been the subject of experimental studies by several groups using state-of-the-art techniques. − Dissociation on the S 1 state, initiated by an excitation based on the phenoxyl ring, produces an H atom and a phenoxyl radical (C 6 H 5 O). , The fragment kinetic energy distribution is structured and wavelength dependent, providing valuable information concerning the internal energy distribution of the phenoxyl product, − ,− , which in turn reflects nonadiabatic dissociation dynamics. At low energies, experimental evidence, including real time measurements and isotope effects, strongly suggest that the dissociation is via tunneling.…”

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confidence: 99%

Nonadiabatic Tunneling in Photodissociation of Phenol

et al. 2016

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Using recently developed full-dimensional coupled quasi-diabatic ab initio potential energy surfaces including four electronic ((1)ππ, (1)ππ*, 1(1)πσ*, and 2(1)πσ*) states, the tunneling dynamics of phenol photodissociation via its first excited singlet state (S1 ← S0) is investigated quantum mechanically using a three-dimensional model. The lifetimes of several low-lying vibrational states are examined and compared with experiment. The deuteration of the phenoxyl hydrogen is found to dramatically increase the lifetime, attesting to the tunneling nature of the nonadiabatic dissociation. Importantly, it is shown that owing to the conical intersection topography tunneling in this system cannot be described in the standard adiabatic approximation, which eschews the geometric phase effect since the nonadiabatically computed lifetimes, validated by comparison with experiment, differ significantly from those obtained in that limit.

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“…However, the energy of former vibration, measured and computed for free molecule at about 300 cm À1 [24,27], shifts significantly to higher values in the solid state (684 cm À1 [24]). In the present work, the investigation of the 700-500 cm À1 region of natural 4-HBAH spectrum shows that the only deuteration sensitive absorption is that with maximum at 619 cm À1 .…”

Section: Bending Vibrations Of the Nh 2 Nh And Oh Groupsmentioning

confidence: 91%