All-valence-electron scf-mo calculations on the electronic structure and reactivities of some halogenated benzene and azabenzene derivatives

All-valence-electron CNDO/2 SCF-MO calculations have been performed on some fluoro, chloro and methoxy derivatives of benzene, pyridine and the diazines. The computed charge distributions and the dipole moments are discussed and compared with available experimental data. The relative basicities of the derivatives of pyridine and the diazines have been investigated and an attempt made to correlate the results with known pK_a values. Localisation energies for the nucleophilic substitution of halogen by methoxide ion have also been calculated and the predicted relative reactivities compared with experimental observations, where these were available.     

The study on supported Fe and FeMo hydrotreating catalysts by combining Mössbauer spectroscopy and ordinary γ-ray transmission

From in-situ Mössbauer spectra recorded at room temperature it is concluded that the support material (carbon or alumina) influences the degree of sulfidation of Fe and FeMo hydrotreating catalysts. For the latter a Fe?Mo?S phase is observed. By combining Mössbauer spectroscopy and ordinary γ-ray spectroscopy the sulfur uptake by the catalyst has been studied.     

The Will of the People

The paper discusses the cybernetic mechanisms whereby our institutions fail to translate the will of the people into effective policies, and those by which the will of the people is an attenuated version of human potentiality in the first place. A systemic model is developed to account for the observed phenomena in terms of a cybernetic theory of the management process, and this is then exemplified from current dilemmas facing humankind. The model is subsequently extended to encompass the theory of viable systems, the principle of self-reference, and a model of self-hood which promotes new concepts that close the model into its starting point of human potential. The total approach bears on the capability of individuals, groups, institutions, societies and nations to realize themselves, and to thwart the dangers in which our civilization is plunged.     

Measurement of the hyperfine splitting of the 1s state in muonic 7Li as a search for axial-vector muon-nucleon interactions

The magnetic hyperfine splitting (h.f.s.) in the 1s state of ⁷Li has been measured with a precision of 1% using the bent-crystal spectrometer facility at the SIN muon channel. With an instrumental resolution of 2.5 eV FWHM the h.f.s. was completely resolved in the 2p-1s transition. The result is ΔE(M1) = 4684 ± 49meV. A comparison of this result with the electromagnetic value yields a new upper limit for the strength of a possible muon-nucleon interaction mediated by an axial-vector boson, which is much lower than those that can be derived from other present data.     

Pionic K X-rays in liquid He

Energies and lorentzian widths of pionic K X-ray transitions have been measured in liquid ³He with improved accuracy. The strong interaction on the π³He 1s level is found to be attractive and to produce an increase in the K transition energies of 34 ± 4 eV; the measured lorentzian width is 36 ±7 eV. Measured values are also presented for K X-ray energies in liquid π⁴He and μ⁴He, the lorentzian width of the 1s level in π⁴He, and relative intensities of K X-ray transitions in π³He, π⁴He and μ⁴He. The measurements are compared with those of others and with recent theoretical calculations.     

X-rays from antiprotonic helium in helium gas

X-ray transitions to the 4F, 3D, and 2P atomic levels of p?He have been observed with antiprotons stopped in He gas at 4 and 1.1 atm NT. The population by radiative transitions of the 3D level in gas Y_M(4atm) = (28±14)% and Y_M(1.1 atm) = (43±22)% exceeds by more than one order of magnitude that measured in liquid He. The annihilation width of the 3D level Γ^a_3D = 2.8±1.0 × 10^?3eV is determined from the ratio between the numbers of X-rays feeding and depopulating the 3D level. The strong-interaction shift of the 2P level ε(2P) = ?14±6 eV is obtained by inputting the $\text{p}\text{He}$ experimental X-ray yields into a cascade calculation, the results of which are in good agreement with well-established data from muonic, pionic, and kaonic helium.     

Novel heteropentalenes. Synthesis of heteropentalenes from tetrahydroimidazo [1.2-d]-(1,2,4)-thiadiazoles and conversion of certain heteropentalenes to benzothiazole derivatives

Oxidation of 1 - phenylcarbamoylidazolidine - 2 - thione gives 2,3,5,6 - tetrahydro - 2 - phenylimidazo [1,2-d]- (1,2,4) - thiadiazole - 3 - one which undergoes addition reactions with heterocumulenes leading to various heteropentalenes. Oxidation of 1 - phenylthiocarbamoylimidazlidine- 2 - thione yields 1- (benzothiazol - 2- yl) - imidazolidine - 2 - thione, also obtained by acid catalysed decomposition of 3,4 - ethano - 2,3,4,5 - tetrahydro - 2, 5 - bisphenylimino - 1,6,6aS^IV - trithia - 3,4 - diazapentalene. A similar acid catalysed decomposition to a benzothiazole occurs with 2,3,4,5 - tetrahydro - 1,6 - diphenyl - 3,4 - propano - 6aS^IV - thia - 1,3,4,6 - tetraazapentalene -2, 5- dithione.