Search results for "Uv spectra"

Verschiedenartige Additionsreaktionen von 2-Cyano-2-propylradikalen an p-Tolylmethacrylat und 4-Cyclohexylphenylmethacrylat

1976

Durch Umsetzung von p-Tolylmethacrylat oder 4-Cyclohexylphenylmethacrylat in stark verdunnter, siedender Benzollosung mit einem sehr grosen Uberschus an 2,2′-Azoisobutyronitril wurden die erwarteten Additionsprodukte mit 2-Cyano-2-propylradikalen (1) erhalten, namlich p-Tolyl- bzw. 4-Cyclohexylphenyl-[4-cyano-2-(2-cyano-2-propyl)-2,4-dimethyl]valerianat (3a bzw. 3b) mit rund 50% Ausbeute. Daneben wurden p-Tolyl- bzw. 4-Cyclohexylphenyl-(4-cyano-4-methyl-2-methylen)valerianat (4a bzw. 4b), p-Tolyl- bzw. 4-Cyclohexylphenyl-[4-cyano-2(2-cyano-2-methyl-1-propyl)-4-methyl]valerianat (5a bzw. 5b), p-Tolyl- bzw. 4-Cyclohexylphenyl-(4-cyano-2,4-dimethyl)valerianat (6a bzw. 6b) und p-Tolyl- bzw. 4-C…

Valorisation of Cashew Nut Shell Liquid Phenolics in the Synthesis of UV Absorbers

2019

Structural and spectroscopic characterisation of 2-(2'-hydroxybenzoyl)pyrrole and its O-methyl derivative

2004

Abstract Density functional theory calculations on the tautomeric and conformational equilibria of 2-(2′-hydroxybenzoyl)pyrrole (HBP) and 2-(2′-methoxybenzoyl)pyrrole (MBP) were performed. Moreover, the experimental IR and UV spectra of the same compounds were recorded and compared with the theoretical data. The presence of an intramolecular hydrogen bond in HBP can be related to the biological activities of some of its derivatives.

Concentriols B, C and D, three squalene-type triterpenoids from the ascomycete Daldinia concentrica

2002

Abstract Three squalene-type triterpenoids named concentricols B, C and D ( 1 – 3 ) were isolated from the ethyl acetate extract of fruiting bodies of the xylariaceous ascomycete Daldinia concentrica . Their absolute structures were elucidated by analysis of 2D NMR, MS, IR and UV spectra, and the modified Mosher's method.

Die Dissoziationskonstanten von 2,2?-Dihydroxydiphenylmethanderivaten

1973

The pK-values of the first and second degree of dissociation of 2.2′-dihydroxy-5-methyl-3′.5′-dinitro-diphenylmethane, 2.2′-dihydroxy-5-methyl-5′-nitro-diphenylmethane and 2.2′-dihydroxy-5.5′-dimethyl-3′-nitro-diphenylmethane were determined in aqueous solution at 25°C spectrophotometrically. Comparing the observed pK-values with those of 2-methyl-4.6-dinitrophenol, 2-methyl-4-nitrophenol, 2.4-dimethyl-6-nitro-phenol and 2.4-dimethylphenol, we found a decrease of the values of pK1 and an increase of pK2. We explain this by the formation of an intramolecular hydrogen bridge which stabilizes the anion of the half dissociated form. This assumption is supported by the UV spectra.

Simulation of the VUV spectral emission from the JT-60SA divertor

2021

A divertor survey dual-spectrometer is being designed by an EU-Japan team [1] to be installed on JT-60SA [2], the new fusion experiment expected to start operating in 2020. Positioned on an upper port, the primary role of the spectrometer is to analyse the radiation losses in the divertor region and to aid studying the physics of the divertor plasmas, including plasma detachment. Its spatial resolution capability is around 10 cm at the divertor and its two branches together cover the wavelength range from 10 to 130 nm, to satisfy the physics scope [3]. The spectrometer Lines Of Sight (LOS) are mapped onto a 2D SOLEDGE [4] simulations of the divertor region carried out for different density …

Chemical Constituents of Urospermum picroides

1992

Seven phenolic compounds were isolated from the aerial parts of U. picroides. They were identified by UV spectra, TLC and HPLC-DAD as luteolin, luteolin-7-glucoside, quercetin, quercetin-3-galactoside, kaempferol-3-galactoside, chlorogenic and isochlorogenic acids. Other phenolics were characterized by HPLC-DAD analysis: gallic, protocatechuic, caffeic, ferulic and isoferulic acids, quercetin-3-glucoside and luteolin-4′-glucoside.