Showing papers in "Journal of Photochemistry in 1984"

TL;DR: In this paper, the authors presented quantiques quantiques d'isomerisation trans-cis and cis-trans a 313 and 436 nm, respectively, for azobenzene.

TL;DR: In this paper, the production and quenching of singlet oxygen O2(1Δg) by the sensitizer in dye-sensitized photo-oxygenations are studied.

TL;DR: In this paper, the low-lying A states of trans-stilbene were investigated by means of two-photon excitation spectroscopy and the experimental results were compared with theoretical results.

TL;DR: The results of this study suggest that the porphyrins sensitize Singlet oxygen efficiently but that the singlet oxygen is rapidly scavenged by substrates such as methionine and other amino acids.

TL;DR: In this article, the originine des impuretes photosensibilisantes dans les polymeres is described, and the photostabilisation controlee dans le temps is discussed.

TL;DR: In this paper, the b1Σ+(b0+) → X3Σ−(X10+, X21) and a1Δ(a2) → X 3 Σ− (X10+X21) transitions of group VI and group VII diatomic molecules in the near-IR spectral region were investigated by chemiluminescence measurements, excimer laser pulse photolysis and dye laser fluorescence.

TL;DR: In this article, the use of a liquid-nitrogen-cooled germanium detector was used to measure singlet oxygen production in the lactoperoxidase (HOG) and HOG-halide systems.

TL;DR: In this article, a biphenyl cosensitization mechanism for 9,10-dicyanoanthracene (DCA) is presented. But the authors do not consider the effect of biphenyclic acid as a cosensitizer for photo-oxygenation.

TL;DR: The initial experimental results are described and the experimental design was found to be very flexible and easily adaptable to different problems, and it is explained in detail.

TL;DR: In this article, the efficiency φΔ of the generation of singlet oxygen 1O2* via oxygen quenching of triplets of a number of substrates of photochemical and photobiological interest was studied by 337.1 nm laser flash photolysis using 1,3-diphenylisobenzofuran as the monitor for 1O 2 *.

TL;DR: In this paper, solvent-dependent fluorescence emission of 7-Alkoxy and 4-methyl-7-alkoxy coumarins was exploited as a probe to measure the surface polarity of the micelles formed by ionic (sodium dodecylsulphate and cetyltrimethyl-ammonium bromide) and non-ionic detergents.

TL;DR: In this paper, a two-stage process with a molecular species, presumably O2, as the transfer agent was proposed to excite the b state of O3P in the terrestrial v′ = 0 bands.

TL;DR: In this article, the photolysis of a series of aminocoumarin laser dyes, including 7-diethylamino-4-methyl coumarin (1), has been investigated.

TL;DR: In this paper, the absorption and fluorescence of pyrenealdehyde have been utilized to probe the nature of sites in solid zeolites that adsorb aromatic molecules, and excimer formation is found for pyrenealde adsorbed on type Na+Y zeolite.

TL;DR: In this article, the photoenolization of 2-methylbenzophenone in ethanol at room temperature was investigated using photosecond and nanosecond spectroscopy methods.

TL;DR: The rate of formation of O2(b) when oxygen atoms recombine has been monitored in a fast flow system by following the emission at 762 nm as a function of time.

TL;DR: In this paper, the pH dependence of the absorption and fluorescence spectra of the alkaloids harmaline and harmalol was investigated, and the p K a values associated with the ground state equilibria were determined spectrophotometrically.

TL;DR: A survey of excitation processes for singlet O 2 in planetary atmospheres can be found in this article, where the authors provide an introduction to the following papers in which laboratory investigations and field measurements are discussed in more detail.

TL;DR: In this paper, it was deduced that the photodissociation of 2,2,4-trimethyl-1,2-dihydroquinolines occurs from higher triplet states which are populated by intersystem crossing from the S2 state.

TL;DR: The results indicate that Rose Bengal plus visible light can cause biological damage without the intermediacy of reactive oxygen species, i.e. Rose Bengal andvisible light can react directly with biological material, in reactions that appear to be type I photosensitized processes, independent of singlet oxygen as an intermediate.

TL;DR: In this article, a Holobeam model 255 Nd-YAG laser with an output at 1065 nm was used to achieve the transition O 2 ( 3 Σ g −, v = 0) → O 2( 1 Δ g, v = 1) The mean lifetime τ of the resulting excited oxygen species in the gas phase at atmospheric pressure was measured to be 0.124 ± 0.012 s.

TL;DR: The photoredox behavior of the Cu(I)-CN system in aqueous solutions was studied in this article, where the cyanide content decreased on irradiation at 253.7 nm and the quantum yield ΦCN for cyanide conversion was determined at various pH values.

TL;DR: In this article, the absorption and emission properties of Ph3P, MePh2P and Ph2P(CH2)nPPh2 (from n = 1 to n = 6) (Ph  phenyl; Me  methyl) are reported.

TL;DR: In this article, the authors show that large viscosity changes are induced by small changes in solubilizate concentration caused by photodimerization of the anthracenes at wavelengths exceeding 300 nm.

TL;DR: In this paper, the light-induced oxygenation of lignin was studied with the aid of Lignin model compounds in a dimethoxyethane solution saturated with air or oxygen.

TL;DR: The reactivity of fresh precipitated amorphous titanium dioxide and colloidal titanium dioxide is attributed to the formation of titanium(III) species rather than electron-hole pairs as discussed by the authors.

TL;DR: In this article, the overall quantum yield of tetracene-, rubrene- and heterocoerdianthrone-sensitized photoperoxidation of 1,3-diphenyl-isobenzofuran and self-sensorized photoprocessing of 9,10-dimethyl-anthracene was investigated.

TL;DR: In this article, X-ray crystal structure analyses of 7-chlorocoumarin and 7-methoxycoumarins reveal unusual features, such as the positions of the reactive double bonds of these two coumarins, which are rotated by about 65° with respect to each other.

TL;DR: In this paper, the authors investigated the relaxation of electronically excited nitro aromatic compounds, in particular 3,5-dinitroanisole (3-DINA), by means of picosecond and nanosecond laser kinetic spectroscopy.