A spectroscopic study of proton transfer and photochromism in <i>N</i>-(2-hydroxybenzylidene)aniline

Lewis, James W.; Sándorfy, C.

doi:10.1139/v82-237

Cited by 57 publications

(25 citation statements)

References 5 publications

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“…Conventional 18,19 and time-resolved infrared spectroscopy 20,21 were used to identify the photoproducts of irradiated salicylidene aniline in solution, polycrystalline film and encaged in zeolites.…”

Section: Introductionmentioning

confidence: 99%

Structure and Photochemistry of N-Salicylidene-p-carboxyaniline Isolated in Solid Argon

Avădanei¹,

Kuş

Cozan³

et al. 2015

J. Phys. Chem. A

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Infrared matrix isolation spectroscopy and DFT/B3LYP/6-311++G(d,p) calculations have been used to characterize the conformational space of the enol-imine and keto-amine tautomers of N-salicylidene-p-carboxyaniline (SCA) in both their E and Z isomeric forms. Monomers of SCA were isolated in an argon matrix (15 K), which was shown to contain only the most stable conformer of the E-enol isomer of the compound. The matrix-isolated E-enol was then subjected to in situ UV irradiation (λ = 335; 345 nm, provided by a laser/MOPO system, or λ > 235 nm, provided by a Hg(Xe) broad-band source), and the photoinduced processes probed by infrared spectroscopy. Two photoreaction channels were observed, with a branching ratio of ∼1:1, corresponding to E-enol → Z-enol isomerization and E-enol → E-keto tautomerization. Both processes were found to be rather effective, with practically complete consumption of the reactant after broad-band irradiation by 1 min only. Identification among the photoproduced species of the Z-enol conformer that differs from the reactant only by E-to-Z isomerization suggests the initial photoproduction of this conformer, which subsequently decays into the lowest energy Z-enol conformer (also identified experimentally). The E-enol → E-keto tautomerization requires an excited state intramolecular proton transfer and twisting about the exocyclic CC bond of the molecule. These processes most probably take place sequentially. However, in the present study the Z-keto isomer, which should act as intermediate in this sequence of processes, could not be detected, most probably due to its short lifetime under the used experimental conditions. On the contrary, the detailed structural and vibrational characterization of the photoproduced E-keto form was successfully achieved.

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Section: Introductionmentioning

confidence: 99%

Structure and Photochemistry of N-Salicylidene-p-carboxyaniline Isolated in Solid Argon

Avădanei¹,

Kuş

Cozan³

et al. 2015

J. Phys. Chem. A

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“…[9][10][11][12][13][14][15][16][17][18][19][20]22,23,[25][26][27][28][29] However, the solvent effect may significantly influence the excited-state dynamics of SA in the condensed phase, because a large change in the geometry occurs during the photochromic reaction of SA. Femtosecond real-time probing of the excited states in a molecular beam is crucial for complete understanding of the ultrafast processes in SA.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast excited-state dynamics in photochromic N-salicylideneaniline studied by femtosecond time-resolved REMPI spectroscopy

Okabe

Nakabayashi

Inokuchi

et al. 2004

The Journal of Chemical Physics

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Articles you may be interested inCommunication: Ultrafast time-resolved ion photofragmentation spectroscopy of photoionization-induced proton transfer in phenol-ammonia complex Ultrafast nonradiative dynamics in electronically excited hexafluorobenzene by femtosecond time-resolved mass spectrometry Ultrafast processes in photoexcited N-salicylideneaniline have been investigated with femtosecond time-resolved resonance-enhanced multiphoton ionization spectroscopy. The ion signals via the S 1 (n,*) state of the enol form as well as the proton-transferred cis-keto form emerge within a few hundred femtoseconds after photoexcitation to the first S 1 (,*) state of the enol form. This reveals that two ultrafast processes, excited-state intramolecular proton transfer ͑ESIPT͒ reaction and an internal conversion ͑IC͒ to the S 1 (n,*) state, occur on a time scale less than a few hundred femtoseconds from the S 1 (,*) state of the enol form. The rise time of the transient corresponding to the production of the proton-transferred cis-keto form is within 750 fs when near the red edge of the absorption is excited, indicating that the ESIPT reaction occurs within 750 fs. The decay time of the S 1 (,*) state of the cis-keto form is 8.9 ps by exciting the enol form at 370 nm, but it dramatically decreases to be 1.5-1.6 ps for the excitation at 365-320 nm. The decrease in the decay time has been attributed to the opening of an efficient nonradiative channel; an IC from S 1 (,*) to S 1 (n,*) of the cis-keto form promotes the production of the trans-keto form as the final photochromic products. The two IC processes may provide opposite effect on the quantum yield of photochromic products: IC in the enol form may substantially reduce the quantum yield, but IC in the cis-keto form increase it.

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“…The deep‐red color can be erased by irradiation with visible light or by thermal fading in the dark. Although many studies have been performed over the last three decades, there remains a controversy about the structure of the colored species …”

Section: Photochromism Of Salicylideneanilinesmentioning

confidence: 99%

Direct Observation of Unstable Reaction Intermediates by Acid‐Base Complex Formation

Ohashi¹

2013

The Chemical Record

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The structures of several unstable or metastable reaction intermediates that were photoproduced in crystals were analyzed by using X-ray techniques. The presence of enough void space around the reactive group(s) is an essential factor for the reaction to occur with retention of the single-crystal form. To expand the void space, an acid group (COOH) was substituted onto the reactant molecule and acid-base complex crystals were prepared with several amines, such as dibenzylamine and dicyclohexylamine. Following the formation of such acid-base complexes in crystals, the metastable structures of nitrenes and red species of photochromic salicylideneanilines have been successfully analyzed by using X-ray techniques. Moreover, the structure of a Pt complex anion in the excited state has been analyzed, which formed acid-base complex crystals with various alkylammonium cations. The formation of acid-base complexes will be a powerful tool for directly observing the structure of unstable or metastable reaction intermediates by using X-ray techniques.

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A spectroscopic study of proton transfer and photochromism in N-(2-hydroxybenzylidene)aniline

Cited by 57 publications

References 5 publications

Structure and Photochemistry of N-Salicylidene-p-carboxyaniline Isolated in Solid Argon

Structure and Photochemistry of N-Salicylidene-p-carboxyaniline Isolated in Solid Argon

Ultrafast excited-state dynamics in photochromic N-salicylideneaniline studied by femtosecond time-resolved REMPI spectroscopy

Direct Observation of Unstable Reaction Intermediates by Acid‐Base Complex Formation

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