Reaction of 3,6-disubstituted 4-nitropyridazine 1-oxides with methanolic ammonia and liquid ammonia

Reaction of 3-chloro-6-methyW-nitropyridazine 1-oxide ( 5 ) with methanolic ammonia at 0° led to a replacement of the chlorine atom by a methoxy group as well as by an amino group. Reaction of the 3-methoxy-6-methyl-4-nitropyridazine 1-oxide ( 6 ) with the same reagent led to amino-demethoxylation; this replacement reaction was very slow. Attempts to perform these reactions with liquid ammonia failed. Pmr spectroscopy of solutions of compound 6 in methanolic ammonia revealed that no σ-adduct was present. However in liquid ammonia a 1:1 σ-adduct at C-5 i.e. 12b was formed. 3,6-Dimethoxy-4-nitropyridazine 1-oxide (7) gave with methanolic ammonia an amino-demethoxylation at C-6. No σ-adduct could be detected by pmr spectroscopy. However, in liquid ammonia convincing pmr data were obtained showing the presence of a 1:1 σ-adduct at C-5.     

A 13C NMR study of β-carboline alkaloids

The ¹³C NMR spectra of β-carboline alkaloids were determined, and unambiguous assignments of the spectra were carried out from the long-range coupling constants.     

Core-exciton induced resonant photoemission in the covalent semiconductor black phosphorus

Valence band photoemission spectra of black phosphorus have shown anomalous behavior at the excitation of 2p core-excitons. The intensity of the 2.7 ev peak shows a clear Fano type interference due to a direct recombination of core-excitons leaving one hole in valence bands. Besides, strong enhancement of the 10.8 eV peak is interpreted as due to a core-exciton induced resonance with two-hole final states. The role of core-excitons as intermediate states for photoemission processes is newly revealed in the experiments.     

Ultraviolet photoemission and 4d core reflectance spectra of SmSe(100)

Ultraviolet photoemission (UPS) and inner core reflectance spectra have been measured on SmSe(100) surface with synchrotron radiation. Besides the multiplet structures observed in UPS spectra for the Sm 4f, 5p and 5s excitations, the reflectance spectrum has revealed a multiplet structure associated with the Sm 4d→4f excitation. Each band of the UPS spectra has shown remarkably different hν dependence and the resonant behavior of the cross section. Sm 4f- and Se 4p-derived valence band features are unambiguously identified by the angle resolved UPS.     

β-Lactams via photochemical reaction of monothioimides

Photolysis of acyclic monothioimides gave β-lactams and thioamides via Type II reaction involving γ-hydrogen abstraction by thiocarbonyl group.     

Spin-parity assignments of excited states in 12C

The reaction ¹²C(α, α')¹²C¹(3α) is observed by using 90 MeV a-particles in ionographic matter. The energies of the three α-particles from the break-up of ¹²C¹ are plotted in Dalitz diagrams. The density distributions for the three α-particles in the diagrams are calculated by assuming the spins and parities for the states in ¹²C¹(3α). The spin-parities for the states are assigned by comparing the observed density distributions with those calculated.     

Lattice supersymmetry and the nicolai mapping

We propose the use of the Nicolai mapping as a guiding principle for formulating supersymmetric theories on a discrete space-time lattice, on which the supersymmetry algebra is not well-defined. We present a discretized form of the N = 2 Wess-Zumino model in 1+1 dimensions. This model is also examined in the hamiltonian (continuous time) formalism on a spatial lattice, and is found to allow consistent discretization only for those subalgebras which admit an internal O(2) symmetry.