DIBUTADIENYL PIPERAZINE,DIBUTADIENYL HOMOPIPERAZINES AND BUTADIENYL-SUBSTITUTED PIPERIDINES FROM MONOSUBSTITUTED HALODIENES

Compounds 3a–k were obtained from the reactions of compounds 1a–k with homopiperazine (2) in CH ₂ Cl ₂ . Compounds 1a–b, 1d–f, and 1h–l gave compounds 5a–b, 5d–f, and 5h–l with 2-methylpiperazine (4) in dichloromethane. Compounds 7c and 9c were obtained from the reactions of compound 1c with 4-ethoxycarbonyl piperazine (6) and 4-piperidinol (8) in CH ₂ Cl ₂ . Compounds 1a and 1f gave compounds 11a and 11f with 4-methylpiperazine (10), and compound 13f was obtained from the reactions of compound 1f with 4-methylpiperidine (12) in CH ₂ Cl ₂ .     

Synthesis,structural, and spectral studies of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-bis- (5-methylsalicylidene)-2,2′-diamino-4-4′-di-(trifloromethyl)-diphenyl disulfide

A new disulfide compound N,N′-bis-(5-methylsalicylidene)-2,2′-diamino-4-4′-di-(trifloromethyl)-diphenyl disulfide (C₃₀H₂₂F₆N₂O₂S₂) was prepared and characterized by ¹H-NMR, IR, mass spectroscopy, and single-crystal X-ray diffraction. Spectroscopic assignments and the crystallographic results indicate the predominance of the phenol-imine tautomeric form. [For example, N=C double bonds 1.274(9)Å and 1.275(9)Å, two very close hydrogen peaks to the atomic positions of O atoms in difference Fourier map and two strong intramolecular hydrogen bonds (O–H\(\cdots\)N) with O\(\cdots\)N distances of 2.611(10) and 2. 613(8) Åstrongly indicate that this tautomeric form is preferred]. The strong effect of the para CF₃ groups in the molecular and crystallographic arrangement was attributed to the electronegativity of the CF₃ groups.     

Non-Linear Electrodynamics in Blandford–Znajek Energy Extraction

Non-linear electrodynamics (NLED) is a generalization of Maxwell's electrodynamics for strong fields. It has significant implications for the study of black holes and cosmology and has been extensively studied in the literature, extending from quantum to cosmological contexts. In this work, two new ways to investigate these non-linear theories are investigated. First, the Blandford-Znajek mechanism is analyzed in light of this promising theoretical context, providing the general form of the extracted power up to second order in the black hole spin parameter a. It is found that, depending on the NLED model, the emitted power can be extremely increased or decreased, and that the magnetic field lines around the black hole seem to become vertical quickly. Considering only separated solutions, it is found that no monopole solutions exist and this could have interesting astrophysical consequences (not considered here). Last but not least, it is attempted to confine the NLED parameters by inducing the amplification of primordial magnetic fields (“seeds”), thus admitting non-linear theories already during the early stages of the Universe. However, the latter approach proves to be useful for NLED research only in certain models. These (analytical) results emphasize that the behavior of non-linear electromagnetic phenomena strongly depends on the physical context and that only a power-law model seems to have any chance to compete with Maxwell.