Ultraviolet spectra and structure of unsaturated compounds of elements of group IV

Summary In the series of compounds CH₂=CH-(CH₂)_n-XR₃ the greatest bathochromic shift of the absorption bands is observed in the allyl compounds. The magnitude depends essentially on the nature of the atoms of the XR₃ group. The bathochromic shift is maximal for a nonplanar position of the double bond and the C-X bond. The results observed cannot be explained by d- interaction or inductive effect and they are in agreement with the idea of a - interaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12 p. 2203–2206, December, 1964     

Ultraviolet spectra ofα,β-unsaturated γ,δ-epoxycarbonyl compounds

Conclusions The presence of an epoxy ring in the -position of ,-unsaturated compounds is accompanied by a marked bathochromic shift of _max in comparison with similar ,-unsaturated carbonyl compounds without an epoxy ring. This shift is evidently due to conjugation of the oxide ring's electrons with the -electrons of the double bond.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1873–1874, August, 1967.     

Ultraviolet emission spectra of sunbeds

It is well known that UV radiation contributes to the development of skin cancer. Exposure to solar radiation is predominantly responsible for the high incidence rate of skin cancer, but there are also indications that sunbeds are involved. The aim of the present investigation was to determine the UV emission spectra of sunbeds. It included the most common sunbed models, which cover more than 50% of the Swiss market. The UV emission spectra of sunbeds have special characteristics and are different from the sun spectrum, which can be seen in high-resolution spectral measurements. Sunbed emission spectra are similar to the sun spectrum in the UVB (280-320 nm) range but reach values 10 to 15 times higher in the UVA (320-400 nm) range. An average erythema-effective irradiance of 0.33 W/m2 was determined for sunbeds. This corresponds to a UV index of 13, which is significantly higher than the UV index of 8.5 of the high summer sun at noon at intermediate latitudes. The measurements were spread over the whole effective area of the sunbeds, and an inhomogeneous distribution of the irradiances with variations of up to 30% from the average value was found.     

Ultraviolet absorption spectra of some alkylchloramines

The ultraviolet spectra of six alkylchloramines are determined between 220 and 320 nm. The wavelengths of maximum absorption are 244 nm (? = 458 l mol^?1 cm^?1) for monochloramine, 252 nm (? = 372 l mol^?1 cm^?1) for methylchloramine, 251 nm (? = 378 l mol^?1 cm^?1) for ethylchloramine, 250 nm (? = 368 l mol^?1 cm^?1) for isopropylchloramine, 264 nm (? = 354 l mol^?1 cm^?1) for dimethylchloramine and 262 nm (? = 315 l mol^?1 cm^?1) for diethylchloramine.     

Ultraviolet and infrared spectra of substituted indoles

An investigation of the electronic absorption spectra of 5-bromo- and N-methyl indoles in the vapour and liquid state in near u.v. region along with their i.r. spectra in the region 400–4000 cm⁻¹ is presented. The vapour absorption spectra of N-methylindole contains two discrete systems in the region 2906.9-2707.5 Å and 2522-2454 Å. Only one system (2976.2-2844.8 Å) has been photographed in case of 5-bromoindole. The observed bands are interpreted in terms of fundamentals, combinations and overtones. The solution phase spectra contain very limited number of bands in each case. The position of these bands together with the nature of solvents used, has been an indicative of the fact that there is sufficient delocalization of the electrons over both the rings.     

芳基汞化合物的性质研究 VI.某些氯化芳基汞的紫外吸收光谱

The UV spectra of 24 substituted phenylmercuric chlorides as well as α-and β-naphthylmereuric chlorides were measured in ethanolic solutions. The effects of the substitution group on the C-Hg bond and UV spectral characterisics were discussed.     

Ultraviolet photoelectron spectra of some resorcinols and dithioresorcinols

The photoelectron spectra of resorcinol, dithioresorcinol, 4,6-dichlororesorcinol 1, 4,6-dichlorodithioresorcinol 3 and their methyl derivatives were recorded by using He(I) and HE(II) excitations. The assignment of the photoelectron bands was mainly based on relative band intensity variations and on the results of ab initio STO-3G calculations. The results show clear evidence of the presence of intramolecular OH … Cl hydrogen bonding interactions in 1, while no effects of such a bonding was observed in the corresponding dithiocompound 3. These findings are confirmed by the STO-3G calculations. The photoelectron spectra of both 1,3-dithiomethoxybenzene and 1,3-dithiomethoxy-4,6-dichlorobenzene give evidence of rotational isomerism of the SCH₃ group.     

Mass spectra of boron compounds

The infrared and Raman spectra of six compounds (trimethylsiloxyethylene, (CH₃)₃SiOCHCH₂, methoxytrimethylsilane, (CH₃)₃SiOCH₃, and their deuterated derivatives: (CD₃)₃SiOCHCH₂, (CH₃)₃SiOCDCD₂, (CD₃)₃SiOCH₃, (CH₃)₃SiOCD₃ have been analysed.The majority of the bands observed have been assigned, in particular those due to ν(SiO).The study of the vinyl compounds shows that the enoxysilane exists in two conformers, the major being the gauche and the minor the s-cis one.