Synthesis and structure of Schiff bases based on 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde. New sterically hindered bis-catecholaldimines

A reaction of 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde with aliphatic (ethylenediamine, propylene-1,3-diamine, 1,4-diaminobutane) and aromatic (o-, m-, p-phenylenediamines, 1,8-diaminonaphthalene, benzidine) diamines leads to the Schiff bases containing fragments of sterically hindered catechols in high yields (up to 97%). The products exist in two tautomeric forms in solutions and in the crystalline state. In the case of aliphatic diamines, catecholaldimines exist in solutions in the quinomethide form, whereas in the case of aromatic, in the catechol form. In the crystalline state, the position of the hydrogen atom in the O-H…N fragment is also affected by the intermolecular hydrogen bonds, which promote stabilization of the quinomethide form of catecholaldimines.     

Excitation of tornados by squall storms

The theory of tornado generation by squall storms has been constructed. The results of the theoretical calculations are confirmed by field observations and are in good agreement with measurements.     

Spectroscopic Properties of Neodymium Ions in the Crystal Lattice of Gadolinium Titanate

Crystallography Reports - The possibility of using gadolinium titanate single crystals in quantum electronics is considered. This compound has been chosen as a result of consideration of possible...     

Synthesis,Structure, and Electrochemical Properties of New Sterically Hindered o-Benzoquinone—6,9-Di-tert-Butyl-1,2,3a,4-Tetrahydrobenzo[b]oxazolo[3,2-d][1,4]oxazine-7,8-Dione

Crystallography Reports - A new representative of sterically hindered 3,6-di-tert-butyl-o-benzoquinones bearing an annulated tetrahydrooxazolo[3,2-d][1,4]oxazine...     

Effects of 2 particle–2 hole configurations on dipole states in neutron-rich <Emphasis Type="Italic">N</Emphasis> = 80–84 isotones

Starting from the Skyrme interaction SLy4 we study the effects of 2 particle–2 hole configurations on the low-energy electric dipole response in ^130–134Sn. It is shown that the pygmy dipole resonance properties are correlated with the neutron skin thickness. The two-phonon configurations give a considerable contribution to the low-lying E1 strength.     

Synthesis and structure of sterically hindered o-benzoquinone carboxylic acid

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Describing of the properties of quadrupole states in a 94Mo nucleus with skyrme interaction

The influence of coupling between simple and complex configurations on the probabilities of E2 and M1 transitions between vibrational quadrupole states is investigated. The finite rank separable approximation for the Skyrme effective forces is used. Properties of the low-energy spectrum for quadrupole excitations in ⁹⁴Mo nucleus are considered.     

Properties of giant dipole resonance and the elimination of center-of-mass motion

The accuracy of eliminating the spurious state from the E1-transition strength distribution is investigated within the random-phase approximation with separabelized Skyrme forces. The E1-transition strength distribution in ¹³²Sn is considered as an example.     

Pair correlations and the time-dependent Hartree-Fock-Bogoliubov method in the theory of nuclear structure

It is shown that an idea of the superfluidity of nuclear matter and the u-v transformation of Bogoliubov, time-dependent Hartree-Fock-Bogoliubov method have made a strong impact on the development of the modern nuclear theory. Some applications of the Bogoliubov methods to describe properties of the low-lying collective nuclear states and the giant resonances are demonstrated.