Photocycloaddition of 6-chloro-1,3-dimethyluracil to alkenes: synthesis of 1,2-dihydrocyclobuta[d]pyrimidine-4,6 (3H, 5H)-diones

The acetone-sensitized photocycloaddition of 6-chloro-1,3-dimethyluracil to alkenes affords directly 1,2-dihydrocyclobuta[$\text{d}$]pyrimidine-4,6 (3H, 5H)-diones $\text{via}$ 1-chloro-2,4-dimethyl-2,4-diazabichyclo[4.2.0]octa-3,5-diones.     

Fast chemisorption of NO and SO2 on FeOOH crystals

The electrical conductivity changes of α-, β- and γ-FeOOH by adsorption of NO and SO₂ during 1 ms-1 min were determined. The conductivity change consists of fast and slow processes which are presumably caused by fast chemisorption on the oxygen vacancies and by slow one on the surface anions. The rate constants of fast and slow chemisorption were determined from the conductivity changes. The correlations of the rate constants with the compression pressure of specimen, adsorption temperature and original electrical conductivity are given. The order of magnitude of the fast chemisorption rate constants of the three polymorphs is related to the difference in the surface structure.     

Light scattering properties of a rough-ended optical fibre

Uniform wide-angle irradiation of a laser beam is achieved by roughening chemically the output end of an optical fibre. The angular distribution of the scattered light is analysed experimentally as a function of the incident angle of the laser beam into the input end of the fibre and the length of the rough core surface at its output end.     

The magnetic structure of chalcogenid spinel CoRh2S4

Neutron diffraction study on CoRh₂S₄, having the unexpectedly high Néel temperature T_N, shows the layered antiferromagnetic structure. The magnetic moment is (3.0±0.8)μ_B/Co atom. The T_N is confirmed to be 418 K from the temperature dependence of the intensity of the (200) reflection.