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Showing papers on "Benzophenone published in 1975"




Journal ArticleDOI
TL;DR: In this article, two successive processes result in photoproduct generation, one quenching, independent of macroscopic viscosity, and is not simply reflected in the observed quantum yield, the second process involves separation of two caged radicals, and does not occur in rigid media.

73 citations



Patent
George Rosen1
12 May 1975
TL;DR: In terms of photopolymerizable compounds, this paper showed that benzophenone or substituted benzophenones are autophotopolymerisable in compositions with another photinitiator.
Abstract: Compounds containing a benzophenone or a substituted benzophenone moiety are (a) autophotopolymerizable, (b) photopolymerizable in compositions with another photoinitiator, or (c) photoinitiating in compositions with another photopolymerizable material.

40 citations


Patent
George Rosen1
25 Apr 1975
TL;DR: In terms of photopolymerizable compounds, this article showed that benzophenone or substituted benzophenones are autophotopolymerisable in compositions with another photinitiator.
Abstract: Compounds containing a benzophenone or a substituted benzophenone moiety are (a) autophotopolymerizable, (b) photopolymerizable in compositions with another photoinitiator, or (c) photoinitiating in compositions with another photopolymerizable material.

39 citations




Journal ArticleDOI
TL;DR: Both general acid catalysis and general base catalysis were evidenced, with borate, acetate, formate, and phosphate buffers accelerating the conversion of chlordiazepoxide to lactam and nonlinear dependency of the rate constant on buffer concentration was observed.

29 citations


Journal ArticleDOI
TL;DR: In this article, a simple modification of the technique has been used to measure the emission produced when a short-lived species, in this case the benzophenone ketyl radical, is itself excited by absorption of light, a property which is normally observable only when transient species are stabilized in a rigid medium.
Abstract: The optical absorption spectra, kinetic behavior and other properties of numerous short‐lived species have been studied by flash photolysis and pulse radiolysis. By a simple modification of the technique we have now been able to measure the emission produced when a short‐lived species, in this case the benzophenone ketyl radical, is itself excited by absorption of light, a property which is normally observable only when transient species are stabilized in a rigid medium. (AIP)

23 citations


Journal ArticleDOI
TL;DR: In the reaction of benzophenone with phenylmagnesium bromide, the concentration and life-time of the ketyl radical were influenced greatly by the substitution of ortho-hydrogen atoms of both the two reactants by methyl group as discussed by the authors.
Abstract: In the reaction of benzophenone with phenylmagnesium bromide, the concentration and life-time of the ketyl radical were influenced greatly by the substitution of ortho-hydrogen atoms of both the two reactants by methyl group. From the results of visible absorption and ESR measurements and also of product-analysis, the ketyl radical was considered to be a common intermediate towards normal and abnormal reaction products. The existence of an equilibrium between monomeric and dimeric states of the ketyl radical was also proposed.

Patent
12 May 1975
TL;DR: In terms of photopolymerization, the authors showed that benzophenone or substituted benzophenones are autophotopolymerizable in compositions with another photoinitiator.
Abstract: Compounds containing a benzophenone or a substituted benzophenone moiety are (a) autophotopolymerizable, (b) photopolymerizable in compositions with another photoinitiator, and (c) photoinitiating in compositions with another photopolymerizable material.

Journal ArticleDOI
TL;DR: In this paper, the preparation of aryldiazoalkanes from benzophenone hydrazone is described, where the mixture is oxidised with peracetic acid and sodium hydroxide at pH ca. 10 in the presence of a phase transfer catalyst and a trace of iodine.
Abstract: Diazodiphenylmethane has been prepared from benzophenone hydrazone by oxidation with peracetic acid in the presence of a base and a trace of iodine. Two variants of the process are described: (a) benzophenone hydrazone in an organic solvent is oxidised with peracetic acid in the presence of 1,1,3,3-tetramethylguanidine and a trace of iodine; (b) a solution of benzophenone hydrazone, in a two-phase organic solvent–water mixture, is oxidised by adding peracetic acid and sodium hydroxide simultaneously and equivalently at pH ca. 10 in the presence of a phase-transfer catalyst and a trace of iodine. The preparation of a variety of aryldiazoalkanes is reported.

Patent
21 Apr 1975
TL;DR: The benzophenone derivatives are useful as photosensitizers for making photo-curable compositions by blending with photo polymerizable resins, especially photopolymerizable organosilicon resins as mentioned in this paper.
Abstract: Novel benzophenone derivatives represented by the general formula R m 1 --C 6 H 5-m --CO--C 6 H 5-n --R n 2 where R 1 is a halogen atom, a monovalent C 1-10 hydrocarbon, alkoxy, thioalkoxy, amino, or dialkylamino group, R 2 is an unsubstituted or organosiloxy-substituted organosilyl group, and m and n are each integers from 1 to 5. The benzophenone derivatives are useful as photosensitizers for making photo-curable compositions by blending with photo polymerizable resins, especially photopolymerizable organosilicon resins. Such photo-curable organosilicon resin compositions are further useful for making dry-planographic printing plates comprising non-image areas formed from the polymerized and cured layers of the composition.

Patent
20 May 1975
TL;DR: In terms of photopolymerization, this article showed that benzophenone or substituted benzophenones are autophotopolymerizable in compositions with another photoinitiator.
Abstract: Compounds containing a benzophenone or a substituted benzophenone moiety are (a) autophotopolymerizable, (b) photopolymerizable in compositions with another photoinitiator, and (c) photoinitiating in compositions with another photopolymerizable material.

Journal ArticleDOI
TL;DR: In this paper, the mechanism of the electrochemical reduction of (chromium tricarbonyl)-pivalophenone, -benzophenone and -fluorenone was studied by means of polarography and electron spin resonance spectroscopy.
Abstract: The mechanism of the electrochemical reduction of (chromium tricarbonyl)-pivalophenone, -benzophenone, and -fluorenone was studied by means of polarography and electron spin resonance spectroscopy. The polarograms of the complexed ketones in anhydrous dimethylformamide consisted of two well-defined waves: the compounds are reduced to the corresponding radical anions which are further reduced to the dinegative anion. The influence of the Cr(CO)3 group on the half-wave potentials of the first and second wave is discussed.

Journal ArticleDOI
TL;DR: The far-infrared spectra of naphthalene, anthracene, biphenyl, diphenyl ether, diphenylamine and benzophenone are measured in the region about 50-30 cm− at liquid helium temperature as discussed by the authors.

Journal ArticleDOI
TL;DR: The reaction of [Ni(dpb)2] with RCOX (R = Ph or Et; X = Cl or Br) in benzene, in molar ratio 1 : 1, at room temperature, produces nickel(II)-acyl complexes as discussed by the authors.
Abstract: Reaction of the complexes [Ni(dpb)2][dpb = 1,4-bis(diphenylphosphino)butane] and [Ni(dpp)2][dpp = 1,3-bis(diphenylphosphino)propane] with RCOX (R = Ph or Et; X = Cl or Br) in benzene, in molar ratio 1 : 1, at room temperature, produces nickel(II)-acyl complexes. The spontaneous decomposition of these species produces nickel(II) dihalogenodiphosphino-complexes, nickel(0) monocarbonyldiphosphino-complexes, and benzophenone or diethyl ketone.Reaction of [Ni(dpb)2] with PhBr gives [NiBr(Ph)(dpb)], which undergoes ready carbonylation with CO in benzene to give benzoyl bromide.

Journal ArticleDOI
TL;DR: The tertiary amine catalyzed polymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone (HEPBP) in melt and o-xylene solution was studied in this paper.
Abstract: The tertiary amine catalyzed polymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone (HEPBP) in melt and o-xylene solution was studied UV, IR, and NMR spectra of the polymer thus obtained were evaluated and its molecular weight was determined In order to elucidate the polymerization of HEPBP, the model reaction of 2-hydroxybenzophenone with 4-(2,3-epoxypropoxy)benzophenone at an equimolar ratio as well as the reaction of HEPBP with 2,4-dihydroxybenzophenone at a molar ratio of 2:1 was investigated A reaction mechanism was suggested for the polymerization of HEPBP on the basis of the results obtained According to this mechanism, a catalytic center originates during initiation, and that center affords phenoxyl anion by reacting with HEPBP In the following step phenoxyl anion opens the epoxide ring and an alkoxide anion arises The basic alkoxide anion is stabilized by a proton transfer of a phenolic group The successive recurrence of these reactions results in the growth of the polymer c

Journal ArticleDOI
TL;DR: In this paper, the effect of solvent acidity on the reciprocal interconversion of ground state species in water glassy solutions was investigated and it was shown that their reciprocal inter-conversion depends on the environmental conditions.


Journal ArticleDOI
TL;DR: The angular variation of the field for resonance for diphenylmethylene in benzophenone at T?2°K has been measured over the entire unit sphere as mentioned in this paper, and the values of the fine structure tensors T and g and the spatial relationships between the four substitutional sites in the unit cell change as the temperature is lowered from 77 °K to ∼2 K.
Abstract: The angular variation of the field for resonance for diphenylmethylene in benzophenone at T?2 °K has been measured over the entire unit sphere. Both the values of the fine structure tensors T and g and the spatial relationships between the four substitutional sites in the unit cell change as the temperature is lowered from 77 °K to ∼2 °K. The geometrical changes are consistent with a benzophenone phase transition from P212121 to P21 symmetry.

Journal ArticleDOI
TL;DR: A procedure for the determination of low levels of methadone (6-dimethylamino-4,4-diphenylheptanone-3) in serum has been developed and comparison with a combined gas chromatographic-mass spectrometric determination with selected ion monitoring showed identical serum levels.


Patent
Roger A. Mader1
17 Nov 1975
TL;DR: In this article, 2,4'-Dihydroxy-4-pentadecyl benzophenone is prepared by mixing in the presence of an acid catalyst equimolar amounts of meta pentadecyl phenol and parahydroxy benzoic acid.
Abstract: 2,4'-Dihydroxy-4-pentadecyl benzophenone is prepared by mixing in the presence of an acid catalyst equimolar amounts of meta pentadecyl phenol and parahydroxy benzoic acid. Thermoplastic resins, normally susceptible to degradation upon prolonged exposure to ultraviolet light, become resistant to such degradation when a small amount of 2,4'-dihydroxy-4-pentadecyl benzophenone is blended therein.

Journal ArticleDOI
TL;DR: A micro-modification of the benzophenone procedure proposed by Wallace for the determination of 5,5-diphenylhydantoin in blood is described which does not require specialised glassware and avoids the interference caused by chloroform as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the phosphorescence lifetimes of ω-alkenyl esters of p -benzophenone-carboxylic acid have been measured in dilute solution in degassed acetic acid solution.

Journal ArticleDOI
TL;DR: In this paper, two kinds of competitive reaction processes are proposed from the results of the substituent effects for the phenyl ring of toluene, the effect of the additives such as sensitizers and quenchers, and the dependence of the photoreaction yields on the concentration of the additive.
Abstract: Irradiation of N-acetyldiphenylmethyleneamine (II) in toluene solution gave N-(1,1,2-triphenylethyl)acetamide and N-(1,1-diphenylmethyl)acetamide in 11% and 4.4% yields, respectively. The former is an addition product of toluene to the C=N bond of imine II, and the latter a hydrogenation product of II. The same kind of addition and hydrogenation products as those in toluene were obtained on irradiation of imine II in ethylbenzene, cumene, o-, m-, and p-xylene, mesitylene, p-methoxytoluene, and p-cyanotoluene, respectively. Two kinds of competitive reaction processes are proposed from the results of the substituent effects for the phenyl ring of toluene, the effect of the additives such as sensitizers and quenchers, and the dependence of the photoreaction yields on the concentration of the additive. The photoreaction proceeds not only by the “chemical sensitization” mechanism derived from the ketyl radical of benzophenone, a hydrolyzed product of II, but also by the mechanism through the excited state of I...

Journal ArticleDOI
TL;DR: In this article, the syn-isomer undergoes complete iso merization to anti ; for sensitized irradiation, a photoequilibrium state between two isomers is obtained, and two different mechanisms are proposed.
Abstract: syn-anti Photoisomerization of 4-nitrophenylhydrazone of pyri dine-2-aldehyde by direct and benzophenone sensitized excitation has been investigated. For direct irradiation, the syn-isomer undergoes complete iso merization to anti ; for sensitized irradiation,a photoequilibrium state between two isomers is obtained. Two different mechanisms are proposed.

Journal ArticleDOI
TL;DR: The reaction of Pb(OCOCF3)4 with several olefines and conjugated dienes is reported in this article, including 1.4-methanonaphthalene-(2S,9R+2R,9S)-diol-bis-trifluoroacetate.
Abstract: The reaction of Pb(OCOCF3)4 with several olefines and conjugated dienes is reported. The oxidation of styrene, stilbene and 1.4-dihydro-1.4-methanonaphthalene leads to phenylacetaldehyde (1), benzaldehyde (2) and benzophenone (3), and to 1.2.3.4-tetrahydro-1.4-methanonaphthalene-(2S,9R+2R,9S)-diol-bis-trifluoroacetate (8) respectively. Of the conjugated dienes, 1.3-cyclohexadiene yieldscis-2-cyclohexene-1.4-diol bis-trifluoroacetate (4), cyclopentadiene yieldscis-2-cyclopentene-1.4-diolbis-trifluoroacetate (5) andtrans-2-cyclopentene-1.4-diol-bis-trifluoroacetate (6) andE,E-2.4-hexadiene yields the isomers of 3-hexene-2.5-diol bis trifluoroacetate (7). Oxidation of unsaturated steroids such as 2-cholestene, 2-androsten-17-one, 4-cholestene, androsta-4.9(11)-diene-3.17-dione and 3β-acetoxy-5-cholestene results in cholestane-2α,3α-diol diacetate (9), 2α,3α-diacetoxyandrostan-17-one (10) and 1α-acetoxy-2-androsten-17-one (11), in coprostane-4β,5β-diol-4β-trifluoroacetate (12) or coprostane 4β,5β-diol-4β-acetate (12a), 4-cholestanone (13), in 12α-trifluoroacetoxyandrosta-4,9(11)-diene-3.17-dione (14), and in cholestane-3β,5α,6α-triol-3β-acetate-6α-trifluoracetate.