The dependence of the rate of photodecomposition of the dye rhodamine 6G in polymer active elements on the average pump intensity was studied, The service life of such active elements pumped transversely with low-intensity (less than 1 MW cm(-2)) pump pulses was also investigated. When the average intensity was reduced below a certain value, the dye photodecomposition rate decreased significantly and the service life of the active elements rose strongly.

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The photoreactions of 7-diethylaminocoumarin, 4-methyl-7-diethylaminocoumarin, 4-trifluoromethyl-7-diethylaminocoumarin, and 4-N-morpholino-7-diethylaminocoumarin with trans,trans-1,4-diphenyl-1,3-butadiene, which lead to the formation of [2+2]-cycloaddition products, were studied. It was established that photocycloaddition proceeds with the formation of adducts that have a 1-endo-styryl substituent and a 2-exo-phenyl group. The effect of the substituent in the 4-position of the 7-aminocoumarin molecule on the effectiveness of cycloaddition is discussed.

3-Substituted 7-dialkylaminocoumarins were synthesized as a result of the photoreaction of 7-diethylaminocoumarin, 4-trifluoromethyl-7-diethylaminocoumarin, 4-chloro-7-diethylaminocoumarin, 4-(N-morpholino)-7-diethylaminocoumarin, and coumarin-102 (2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]-benzopyrano[6,7,8-ij]quinolizin-11-one) with iodobenzene, 3,4-dimethoxyiodobenzene, isopropyl iodide, and ethyl α-bromoacetate. It was established that electron-acceptor and electron-donor substituents in the 4 position accelerate photosubstitution. The spectral-luminescence characteristics of the compounds obtained were investigated.

ChemInformVolume 20, Issue 45 Heterocyclic Compounds ChemInform Abstract: Photochemical Reactions of 7-Aminocoumarins. Part 4. Reaction of 4-Methyl-7-diethylaminocoumarin (I) with Compounds (II), (IV), (VI) Capable of Photolysis Cleavage. M. A. KIRPICHENOK, M. A. KIRPICHENOK Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorL. M. MEL'NIKOVA, L. M. MEL'NIKOVA Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorL. K. DENISOV, L. K. DENISOV Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorI. I. GRANDBERG, I. I. GRANDBERG Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this author M. A. KIRPICHENOK, M. A. KIRPICHENOK Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorL. M. MEL'NIKOVA, L. M. MEL'NIKOVA Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorL. K. DENISOV, L. K. DENISOV Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this authorI. I. GRANDBERG, I. I. GRANDBERG Mosk. sel'skokhoz. akad. im. Timiryazeva, Moskva 127550Search for more papers by this author First published: November 7, 1989 https://doi.org/10.1002/chin.198945164AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume20, Issue45November 7, 1989 RelatedInformation

The photochemical reactions of 4-methyl-7-diethylaminocoumarin with a series of alkyl halides including isopropyl iodide, allyl iodide, bromoacetone α-bromoethyl acetate, phenacyl bromide, p-bromophenacyl bromide, and chloroacetonitrile, and aryl iodides including iodobenzene, 2-nitroiodobenzene, 3,4-dimethoxyiodobenzene, and 3-iodo-4-methyl-7-diethylaminocoumarin proceed by a radical addition mechanism to give 3-substituted aminocoumarins. A series of 3-substituted 7-aminocoumarins was also obtained as a result of the photochemical reactions of 4-methyl-7-diethylaminocoumarin, with other reagents, having photolabile chemical bonds such as dioxanyl peroxide, phenyl iodosodiacetate, and nitromethane. The luminescence characteristics of the compounds synthesized were studied.

The photochemical reactions of 4-methyl-7-diethylaminocoumarin with the dimethyl ester of acetylenedicarboxylic acid, diethyl ester of maleic acid, and N-phenylmaleimide in the presence of oxygen and acetophenone give products of the heterocyclization at C(6) and C(8) of coumarin fragment with participation of the diethylamino group. The stereochemical structure of the compounds synthesized was demonstrated using PMR spectroscopy. A mechanism was proposed for this reaction involving the formation of an α-amino radical and its addition to the acetylene or olefin, accompanied by attack on the aromatic ring with subsequent aromatization.

AbstractThe photochemical cyclization of the 7‐diethylaminocoumarin (I) with the acetylenedicarboxylate (II) gives a mixture of the regioisomeric pyranoquinolinones (III) and (IV).

The photocycloaddition of trans-stilbene to 7-diethylaminocoumarin, 4-methyl-7-diethylaminocoumarin, and 4-(N-morpholino)-7-diethylaminocoumarin was investigated. Adducts involving stereospecific (2+2)-cycloaddition at the 3–4 bond were isolated. On the basis of the PMR spectra and an x-ray diffraction study, it was established that the phenyl groups in the cycloadducts occupy 1-endo and 2-exo positions.

Adducts of [2 + 2]-cycloaddition to the 3–4 bond were isolated in the photochemical cycloaddition of vinyl butyl ether and acrylonitrile to 4-methyl-7-diethylaminocoumarin. The stereochemical structures of the compounds obtained as isomers of the ″head-to-tail″ type with an endo or exo orientation of the substituents were established by means of PMR spectroscopy. As a result of an evaluation of the effect of sensitizers and one-electron oxidizing and reducing agents it was found that the investigated reactions proceed through the singlet excited states of 7-aminocoumarins. It is assumed that the regiospecificity of the [2 + 2]-cycloaddition is determined by the C(3) reaction center of the coumarin fragment.

The range of one- and two-band lasing in a donor-acceptor system of polymer laser elements is determined for a fixed donor concentration and a varying acceptor concentration. The calculations are made assuming longitudinal pulsed coherent pumping of the donor dye and a radiative mechanism for transfer of electronic excitation energy from the donor to the acceptor. Expressions are derived for the lasing threshold of the system in the fluorescence bands of the donor and the acceptor. The calculated range of one- and two-band lasing in the system of laser dyes was confirmed experimentally.

The principal methods for the synthesis of 7-amino coumarins and their reactivities are described. The luminescence properties and generation characteristics of this important class of organic dyes are examined.