Photochemical Properties of 2-Aryl-3-imino-1-indones

1992 ◽  
Vol 47 (12) ◽  
pp. 1243-1247 ◽  
Author(s):  
I. Timtcheva ◽  
N. Getoff ◽  
P. Nikolov ◽  
R. M. Quint
Keyword(s):  
Absorption Spectrum ◽  
Steady State ◽  
Reaction Mechanisms ◽  
Transient Absorption ◽  
Flash Photolysis ◽  
Uv Light ◽  
Transient Absorption Spectrum ◽  
Light Illumination ◽  
Probable Reaction ◽  
Photochemical Properties

Steady state as well as flash photolysis experiments of 2-aryl-3-imino-1-indones (2-AIID) have been carried out with the aim to learn more about their photochemical properties. It was established that in ethanol these substances exist solely in the keto-enamine-form and are rather photostable under the influence of uv-light. Illumination in dichloroethane, acetonitrile and dioxane is leading to stable photoproducts. A typical transient absorption spectrum of 2-AIID is presented. Probable reaction mechanisms are given.

Steady-State and Flash Photolysis Investigations of 1 H-Indene-l,3(2H)-Dione Derivatives

1991 ◽  
Vol 46 (4) ◽  
pp. 344-350 ◽  
Author(s):  
R. Quint ◽  
G. Grabner ◽  
R. M. Quint ◽  
N. Getoff ◽  
St. Minchev
Keyword(s):  
Steady State ◽  
Reaction Mechanisms ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Uv Light ◽  
Laser Flash ◽  
Reaction Rates ◽  
Alkaline Solutions ◽  
Solvated Electrons ◽  
Probable Reaction

Abstract Pyrophthalone (PP, 2-(2-pyridinyl)-l H-indene-l,3(2H)-dione) and quinophthalone (QP, 2-(2-quinolinyl)- l H-indene-1,3(2 H)-dione) were investigated in various solvents with respect to their photostability. It was found that PP and QP in ethanol as well as QP in cyclohexane are rather stable under steady-state conditions using UV light (λ = 253.7 nm). Conventional as well as laser flash photolysis of airfree aqueous alkaline solutions (pH 12) lead to the formation of different radicals and solvated electrons (eaq). Some reaction rates were determined and probable reaction mechanisms were postulated

ABSORPTION SPECTRUM OF THE CCN RADICAL

1965 ◽  
Vol 43 (10) ◽  
pp. 1795-1830 ◽  
Author(s):  
A. J. Merer ◽  
D.N. Travis
Keyword(s):  
Absorption Spectrum ◽  
Transient Absorption ◽  
Flash Photolysis ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Transient Absorption Spectrum ◽  
Molecular Constants ◽  
Angular Momenta ◽  
Show Evidence ◽  
Vibrational Energy Levels

A new transient absorption spectrum, attributed to the CCN free radical, has been discovered in the flash photolysis of diazoacetonitrile, HC(CN)N2; three electronic transitions, between 3 500 Å and 4 700 Å, have been photographed for both CC14N and CC15N. The ground state of the radical is a 2Πr electronic state, and the three excited states observed are A2Δ, B2Σ−, and C2Σ+. The 2Π and 2Δ states show evidence of Renner–Teller interaction between the vibrational and electronic angular momenta, an effect not observed previously for 2Δ states. Theoretical expressions for the vibrational energy levels of linear triatomic molecules in 2Δ electronic states have been derived, in terms of a parameter η associated with the quartic terms in the potential energy. They are compared with the observed pattern in the ν2 = 1 level of the A2Δ state. The principal molecular constants for CC14N (in cm−1) are as follows:[Formula: see text]

Electronic Spectral Investigations upon the Photochemical Transformations of Some Substituted 1-(N,N-bisacyl)amino-4,5-diphenyl-l,2,3-triazoles

2001 ◽  
Vol 56 (6-7) ◽  
pp. 452-458
Author(s):  
Irina Petkova ◽  
Apostolos J. Maroulis ◽  
Constantina Hadjiantoniou-Maroulis ◽  
Peter Nikolov
Keyword(s):  
Steady State ◽  
Room Temperature ◽  
Uv Light ◽  
Uv Absorption ◽  
Luminescence Spectra ◽  
Model Compounds ◽  
Photochemical Transformations ◽  
Absorption And Luminescence Spectra ◽  
Photochemical Properties ◽  
Substituted 1

Abstract The objective of this report is to investigate the steady state and dynamic photophysical and photochemical properties of 1-(N,N-bisacyl)amino-4,5-diphenyl-1,2,3-triazoles in solvents of dif­ferent polarity at room temperature and in frozen matrix at 77 K. On the basis of the comparison of their UV absorption and luminescence spectra with those of 4,5-diphenyl-1,2,3-triazole and diben-zamide (model compounds), cleavage of the N-N bond in the title compounds after irradiation with polychrome UV light is proved.

Thickness dependence of transient absorption spectrum for InGaN thin films

2003 ◽  
Vol 0 (7) ◽  
pp. 2606-2609
Author(s):  
M.-S. Nomura ◽  
M. Arita ◽  
S. Ashihara ◽  
S. Kako ◽  
M. Nishioka ◽  
...  
Keyword(s):  
Thin Films ◽  
Absorption Spectrum ◽  
Transient Absorption ◽  
Thickness Dependence ◽  
Transient Absorption Spectrum

scholarly journals Attosecond transient absorption spectrum of argon at the L2,3 edge

2018 ◽  
Vol 97 (3) ◽  
Author(s):  
Andrew Chew ◽  
Nicolas Douguet ◽  
Coleman Cariker ◽  
Jie Li ◽  
Eva Lindroth ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Transient Absorption ◽  
Transient Absorption Spectrum

Thiophosphonyl Radicals Photolytic Generation and Reactivity Towards Olefinic Compounds

1985 ◽  
Vol 40 (6) ◽  
pp. 541-543 ◽  
Author(s):  
T. Sumiyoshi ◽  
W. Weber ◽  
W. Schnabel
Keyword(s):  
Absorption Spectrum ◽  
Free Radicals ◽  
Optical Absorption ◽  
Vinyl Acetate ◽  
Optical Absorption Spectrum ◽  
Rate Constants ◽  
Flash Photolysis ◽  
Uv Light ◽  
Strong Band

Upon irradiation with UV light (λ = 347 nm), 2,4,6-trimethylbenzoyldiphenylphosphine sulfide was found to be fragmented into free radicals by α-scission (F(k) = 0.3 ± 0.1): Flash photolysis studies revealed that the optical absorption spectrum of diphenylthiophosphonyl radicals, S = P(Ph)2. possesses a strong band with λmax = 340 nm and a somewhat weaker band with λmax ≈ 500 nm (e340nm = 1.2 ± 0.2) · 104 1/mol cm). The reactivity towards olefinic compounds, M, is 10 to 30 times lower than in the case of O = P(Ph)2 radicals. Typical bimolecular rate constants (in 1/mol s) of the reaction of S = P(Ph)2 with M are: 4 x 106 (styrene), 6.2 x 105 (methylacrylate), 4.2 x 104 (vinyl acetate).

Photoinduced electron transfer in a supramolecular triad system composed of ferrocene-zinc porphyrin-pyridylnaphtha-lenediimide

2007 ◽  
Vol 11 (05) ◽  
pp. 368-374 ◽  
Author(s):  
Shunichi Fukuzumi ◽  
Yukiyasu Kashiwagi
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Transient Absorption ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Zinc Ion ◽  
Transient Absorption Spectrum ◽  
Zinc Porphyrin ◽  
Long Lifetime ◽  
Porphyrin Moiety

A supramolecular ferrocene-zinc porphyrin-pyridylnaphthalenediimide triad is formed by coordinating the pyridine entity of pyridylnaphthalenediimide with the zinc ion of a ferrocene-zinc porphyrin dyad in benzonitrile. The fluorescence of the zinc porphyrin moiety is efficiently quenched by photoinduced electron transfer from the singlet excited state of the zinc porphyrin moiety to the naphthalenediimide moiety. This is followed by subsequent electron transfer from the ferrocene moiety to the zinc porphyrin radical cation to produce the final charge-separated state, ferricenium ion-zinc porphyrin-naphthalenediimide radical anion, which is successfully detected as a transient absorption spectrum in the laser flash photolysis. The decay of the charge-separated state obeys first-order kinetics irrespective of the initial concentration of the charge-separated state to afford a long lifetime (320 μs). This is the first example of a supramolecular triad that has a long lifetime as compared with the charge-separated state lifetime of the component dyad.

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