Photobilin e. Photooxidation von bacteriochlorophyll-e-derivaten

The blue photooxidation products from metall-free derivatives of bacteriochlorophyll e can be purified without decomposition by reversed phase chromatography. They are identified spectroscopically and chemically as open-chain tetrapyrroles and are named photobilins e.     

The tube electrode and e.s.r.

The convective diffusion equation for the downstream distribution of products and intermediates produced on a tube electrode under conditions of laminar flow is solved. For distances which are large compared to the thickness of the electrode, an analytical solution in real space can be found. The solution of the equation has been applied to an apparatus in which the intermediates and products are detected by e.s.r. The species are transported by laminar flow from the electrode through an e.s.r. cavity. Results are presented for two systems and are found to be in good agreement with the theory.     

Base-catalyzed autoxidation of trialkylamines. An e.s.r study

When a freshly distilled tertiary alkyl amine is dissolved in water a base-catalyzed oxidative dealkylation process takes place, leading to the formation of secondary nitroxyl radicals, alkenes and carbonyl-containing compounds.     

Photodynamic activity of chlorin e6 and chlorin e6 ethylenediamide in vitro and in vivo.

Several parameters of chlorin e6 and its derivative chlorin e6 ethylenediamide have been investigated as these compound are potential sensitizers for photodynamic therapy. A study carried out to compare the cellular uptake of the pigments indicates that chlorin e6 ethylenediamide possesses an enhanced affinity for tumour cells and cellular membranes. Comparison of the uptake in induced sarcoma shows that chlorin e6 ethylenediamide is a much better tumour localizer than chlorin e6. The efficiency of phototherapy with chlorin e6 ethylenediamide is higher than that with chlorin e6. These data show the influence of the substitution of the carboxyl groups in chlorin e6 by ester and amide groups on the photosensitizing properties of the pigments.     

Non-linear perturbation functions in the study of electrode kinetics: I. Some theoretical aspects concerning the e., e.c. and catalytic mechanisms

The possibilities offered by the use of nonlinear perturbation functions in electrochemical measurements are presented using as examples the e., e.c. and catalytic reaction mechanisms. The solutions for the diffusion equations are given in particular for two current-time functions: one containing an arbitrary power of time, and the other an exponential function of time.     

(e,2e) Spectroscopy of methane

Measurements are reported on the spectroscopy of methane using the symmetric (e,2e) technique at energies of 600 eV and 1200 eV. The angular correlations of the states with separation energies of 14.2 and 23.1 eV have been measured and compared with the orbital wavefunctions of Snyder and Basch and with some earlier data at 400eV. The angular correlation of the configuration interaction state at 31 eV shows that this state definetely results from the removal of an electron in the 2a₁ orbital. Other structure at high separation energy is also identified with this orbital. Relative strengths of the It₂ and 2a₁ states are compared and found to be in agreement with the theory at 1200eV.     

X-band e.p.r. spectra of mixed-ligand copper(II) complexes

E.p.r. spectra of [Cu(et2dtc)2], Na[Cu(asp/glut)(et2dtc)] and Na2[Cu(asp/glut)(et2dtc)2] in the polycrystalline state have been recorded and discussed. The complexes display an antiferromagnetic exchange interaction, increasing in the order: Na2[Cu(asp/glut)(et2dtc)2] < Na[Cu(asp/glut)(et2dtc)] < [Cu(et2dtc)2] This revised version was published online in June 2006 with corrections to the Cover Date.     

Mass spectrometric determination of cadmium in i.a.e.a. fish solubles

The cadmium content of the I.A.E.A Fish Solubles [A-6 (1975)] was determined by the isotope dilution method. After dry-ashing and dissolution of the specimen, the cadmium was equilibrated with a known amount of ¹⁰³Cd spike, isolated by ion exchange, purified by dithizone extraction, and converted to the sulfide form in 1% H₃PO₄ solution. The CdS precipitate was loaded onto a baked single rhenium filament for mass spectrometric analysis. The ¹⁰³Cd/¹¹⁰Cd ratio was measured to compute the cadmium content of 0.278 ± 0.032 ppm (dry weight basis) in the Fish Solubles.     

The structure of 4-anilinopiperidine analgesics. III. The structure of the acid sulfate of 1(e)-(2-phenethyl)-2(e), 5(e)-dimethyl-4(e)-(N-propylylanilino) piperidine

Institute of Fine Organic Chemistry, Academy of Sciences of the Armenian SSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 2, pp. 141–145, March–April, 1990.     

An e.s.r. study of copper(II) complexes of N-hydroxyalkylsalicylideneimines

X-band e.s.r. spectra of copper(II) complexes of empirical formula Cu(Sal.NCH2CH2O)X (where X= H2O, py or Cl) and [Cu(Sal.NCH2CH2CH2O)]2 (Sal.N= OC6H4CHN) in solid and solution states at room temperature and at 77K are reported. In frozen solution at 77K the spectra show axial symmetry with a dx2−y2 ground state. The in-plane π-bonds show a moderate degree of covalence, while the out-of-plane π-bonds possess ionic character. The orbital populations of these complexes are 70.9, 81.3, 93.3 and 82.4% respectively, indicating a dx2−y2 ground state. This revised version was published online in June 2006 with corrections to the Cover Date.     

Synthesis of(7e,9e,11e,13e)-18,18,18-trifluororetinal (all-trans 5-trifluoromethylretinal)

All-trans-18,18,18-trifluororetinal (2) was synthesized through trifluorocyclocitral (3) as a key intermediate.     

The tube electrode and e.s.r.: Second order kinetics

A radical species is generated on a tube electrode; it is then transported under conditions of laminar flow through an e.s.r. cavity. In the bulk of solution it decomposes by second order kinetics. The convective diffusion equation for this problem is treated by the simulation method. This method is greatly improved if the spatial co-ordinates are suitably distorted. The distortion used in this work is applicable to all problems involving tube and channel electrodes. The results of the calculation are tested using the reduction of nitrobenzene and are found to be in good agreement with experiment. An upper limit is estimated for the second order rate constant for the radical decomposition above which the radicals will not be detected.