A new electronic transition found for the aniline derivatives

From comparisons of the ultraviolet absorption spectra of aniline derivatives in the gas phase with those in solutions, it is here proposed that there is a transition from the ground state to a molecular Rydberg state between the first and second π-type transitions.     

Simultaneous determination of nitrite, nitrate, thiocyanate and uric acid in human saliva by capillary zone electrophoresis and its application to the study of daily variations

Simultaneous determination of nitrite (NO2-), nitrate (NO3-), thiocyanate (SCN-) and uric acid in human saliva was performed by capillary zone electrophoresis using a coated capillary with reversed electroosmotic flow (EOF), using a 100 mM sodium phosphate buffer at pH 6.5 as a running buffer. Saliva samples were deproteinized with acetonitrile and filtered through a membrane filter. The important advantages of the reported method are: simple operation, short analysis time, minimal sample pre-treatment and sample dilution. In order to evaluate the daily variations of the anionic components, the concentrations were determined in the human saliva of four healthy volunteers upon waking and at 2qh intervals during a day.     

Comparison of nonmetal and metal hydrophilic photosensitizer, ATX-S10 (Na) and ATN-2, binding with human serum proteins using spectrophotometry

Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.     

Measurement of the mechanocaloric effect in rubber

An apparatus for measurement of mechanocaloric effect in rubber has been constructed and tested by measuring the thermal response of three rubber materials to mechanical strain. The results obtained were satisfactory. Detailed measurement has been performed on these materials. The entropy changes that accompany elongation were calculated from the experimental results and compared with those derived from literature data and statistical theory of the macromolecular chain. A dissipative effect was found to accompany the rapid deformation of rubber and attributed to viscoelastic irreversibility. An experimental procedure to eliminate this effect was identified. The apparatus, assembled with the readily available components, will be a useful device for introducing the entropy concept in thermodynamics courses.     

Vinylhydroquinone. IV. Preparation and polymerization behavior of 2-methyl-5-vinylhydroquinone derivatives

As in the case of vinylhydroquinone (I), its alkyl-substituted derivative, 2-methyl-5-vinylhydroquinone (II) was found to copolymerize with methyl methacrylate by tri-n-butylborane in cyclohexanone at 30°C. II was prepared from the O,O′-bisether compound, 2-methyl-5-vinyl-O,O′-bis(1′-ethoxyethyl)hydroquinone (III). The monomer reactivity ratios (M₂ = II) were determined to be r₁ = 0.37 and r₂ = 0. No homopolymerization proceeded under the same conditions. Ordinary free-radical initiators, such as azobisisobutyronitrile and benzoyl peroxide, were not effective in the homopolymerization of II. 1:1 Copolymers were obtained from II and maleic anhydride by using tri-n-butylborane as an initiator. The copolymers exhibited no definite melting range and decomposed at 370–375°C endothermally (DSC). The polymerization behavior of III was also investigated. Although tri-n-butylborane did not initiate the homopolymerization of the monomer, azobisisobutyronitrile was capable of initiating the homopolymerization and copolymerization of III. The monomer reactivity ratios (M₁ = styrene) were determined to be r₁ = 0.83 and r₂ = 0.18. The ratios gave the following Q and e values; Q = 0.15 and e = ?2.2.