Photochemical sensitization and magnetic field effect on aerosol particle formation from a gaseous mixture of glyoxal and acrolein

Under light irradiation at 435.8 nm with a medium pressure mercury lamp, pure acrolein (AC) vapour does not produce any deposits, but a gaseous mixture of glyoxal (GLY) and AC produced sedimentary aerosol particles. The nucleation process of the aerosol particles was investigated by measuring He-Ne laser light intensity scattered by the aerosol particles as formed under light irradiation at 435.8 nm. From the dependence of the scattered light intensity on the partial pressure of GLY, it was found that electronically excited GLY in the nπ? state initiated chemical reactions with AC leading to nucleation of the aerosol particles. Magnetic field effects on the nucleation process were measured for a gaseous mixture of GLY and AC. With the application of a magnetic field of 5.3 kG, the nucleation reaction was accelerated, and the convection of the gaseous mixture was changed due to greater heat release during nucleation reaction between GLY and AC. The magnetic field effect on the gaseous mixture is discussed based on the photochemical behaviour of GLY.     

Cyclodextrin-mediated deacylation of amino acid esters with marked stereoselectivity

With respect to the hydrolysis (deacylation) of Z-D(L)-amino acid esters (N-(benzyloxycarbonyl)-D(L)-amino acid p-nitrophenyl esters) mediated by alpha-, beta- and gamma-cyclodextrins (CyDs), a remarkably high enantioselectivity (L/D=9.0) was observed for the deacylation of Ala substrate with gamma-CyD. The kinetic results on the basis of the Michaelis-Menten principle indicate that the enantioselectivity should be mainly originated in the deacylation process of substrates following the formation of gamma-CyD-substrate (1 : 1) complexes. The computer modeling (molecular mechanics) studies on the inclusion complexes are also described.     

Synthesis of a halogenated clavulone analog

A halogenated clavulone analog 1 which has remarkable antitumor activity was synthesized in a stereoselective and enantioselective manner.     

Fluoride complexation of element 104, rutherfordium

Fluoride complexation of element 104, rutherfordium (Rf), produced in the 248Cm(18O,5n)261Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchange chromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the 18O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effects on the fluoride complexation of Rf.     

The philicity of a triplet carbene: additions of diphenylcarbene to styrene substrates

Triplet diphenylcarbene adds to ring-substituted styrenes as an ambiphile, reacting more rapidly with electron-rich or electron-poor styrenes than with styrene itself.     

Copolymerization of propylene oxide and carbon disulfide with diethylzinc–electron-donor catalyst

Copolymerization of propylene oxide with carbon disulfide was studied by using a catalyst consisting of diethylzinc (ZnEt₂) and various electron donors. Tertiary amines, tertiary phosphines, and hexamethylphosphoric triamide were the effective donors for the copolymerization, but ZnEt₂–water, alcohol, and primary or secondary amines having high activities for the homopolymerization of propylene oxide were not effective for the copolymerization of propylene oxide and carbon disulfide. The copolymers obtained were of low molecular weight and had a monomer unit ratio (CS₂/PO) of 0.5–0.7. In addition, a considerable amount of 1,3-oxathioran-4-methyl-2-thion was isolated as a by-product.     

Identification of a new eicosanoid from in vitro biosynthetic experiments with clavularia viridis. Implications for the biosynthesis of clavulones.

A cell-free homogenate of $\text{Clavularia viridis}$ converts tritiated arachidonic acid into a new eicosanoid identified as $\text{4}$ (free acid) by chemical and chromatographic studies in comparison with synthetic substances. The isolation of $\text{4}$ suggests a novel, non-prostanoid type pathway for the biosynthesis of the clavulones.     

Combination of analytical spectrometers and spectroscopic data bases

Most search systems receive input data through manual keyboards in remote terminals for searching spectroscopic data bases for candidate compounds corresponding to unknown samples, but manual input systems are slow, subject to human error and mentally fatiguing. This paper records preliminary attempts to transmit spectroscopie data (peak heights and positions) directly to the data base without manual input and to let the central computer retrieve the best-fitting data and transmit them to the ramote terminals. First the spectroscopie data were digitized, exact correspondence between the intensities and peak positions being maintained. Chart data were digitized automatically; tests were made for n.m.r. and i.r. data. Direct connexion of an infrared spectrometer to the data base was also tested. Error corrections were made during the transfer processes to ensure exact spectroscopic information. The data were also concentrated for brevity and minimization of error. Two re-transmission systems were tested. In the final step, peak positions and heights were extracted from the transferred data, and the results were used for the search of the i.r. data base. Performance tests showed a considerable degree of success.