Nonlinear nanoantenna with self-tunable scattering pattern

A new concept of a nonlinear plasmonic nanoantenna with self-tunable scattering pattern (indicatrix) is suggested. It is shown that the onset of modulational instability in a nanoantenna consisting of two identical nonlinear metallic nanoparticles results in dynamic energy exchange between the eigenmodes of the nanodimer, accompanied by periodic rotation and switching of the scattering pattern. Such a nanoantenna features a wide scanning sector, a relatively low working threshold, and a short response time. This makes it attractive for applications in nanophotonics and biology.     

Structure and kinetic stability of 1-hydroxy-and aminoalkalnesulfinates in aqueous solutions

The structural parameters of the molecules of sodium hydroxymethane-, 1-hydroxyethane-, 1-hydroxypropane-, aminomethane-, and dimethylaminomethanesulfinates, aminoiminomethanesulfinic acid, and thiourea dioxide were studied by Hartree-Fock-Roothaan and DFT quantum-chemical calculations. The C-S bond length in these molecules varies in the same direction as the constants characterizing their decomposition in aqueous solutions.     

2-Benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide and Its Analogs in Aza-Michael Reaction

2-Benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide and its analogs have been introduced in the aza-Michael reaction with hydrazine derivatives. Novel polysubstituted nitrosulfolenes have been obtained; their structures have been confirmed using ¹Н NMR and IR spectroscopy as well as X-ray diffraction analysis.     

Reactions of 1-nitrocyclohexene with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-binucleophiles

A modification of 1-nitrocyclohexene synthesis is proposed; its reaction with phenylhydrazine and benzoic acid hydrazide is shown to afford monoadducts, and with hydrazine hydrate, bisaduct. With diphenylguanidine occurs heterocyclization to 1-phenyl-2-N-phenylamino-4,5,6,7-tetrahydrobenzimidazole, whose structure is confirmed by the X-ray diffraction data. The analysis performed for this compound of the electron density distribution function in the crystal made it possible to estimate the charge distribution, π-electrons delocalization nature, and the role of N-H…N, C-H…H-C and C-H…C interactions in the formation of the crystal packing.     

213Bi production and complexation with new picolinate containing ligands

Journal of Radioanalytical and Nuclear Chemistry -     

Ab initio Study of the Structure of the Molecular Forms of C3H4O2

The geometrical parameters, force fields, and vibration frequencies were calculated by the ab initio SCF MO LCAO technique using extensive basis sets of Cartesian Gaussian functions for a number of structural isomers of the C₃H₄O₂ molecule. The relative energies of all the isomers were refined in terms of second-order Möller–Plesset (MP2) perturbation theory including electron correlation. For the most energetically favorable forms of the C₃H₄O₂ molecule, geometry optimization was fulfilled in the MP2 approximation. For the main conformer, -hydroxypropenal, possessing a chelate OCCCO fragment, the data are compared with the experimental and theoretical data available in the literature. The MP2 calculated internuclear distances and bond angles are in good agreement with the experimental values. For each form of the C₃H₄O₂ molecule, the geometrical and electronic structure is analyzed. It is shown that the presence of an intramolecular hydrogen bond is the characteristic feature of the structure of the isomers and an additional stabilizing factor.     

Observed two-dimensional tunnel bifurcations in an external electric field

The controllability problem for two-dimensional dissipative tunneling in the system of tunnel-coupled quantum dots (a quantum molecule), interacting quantum molecules, and the system “ACM/CTM cantilever tip-quantum dot” simulated by a 2D oscillator potential in a heat bath and an external electric field is investigated. The obtained results qualitatively correspond to the separate experimental volt-ampere characteristics (VACs) for the system “platinized ACM/CTM cantilever tip-gold quantum dot” obtained at Scientific-Research Physical-Technical Institute with Nizhnii Novgorod State University. The previously-predicted 2D tunnel bifurcations with dissipation for the case of interacting particles tunneling in parallel are found to be experimentally observed and stable.     

The chemistry of bicyclic bisureas

Conclusions A general preparative method has been developed for the alkylation of BBU with various structures using alkyl iodides and liquid ammonia by the action of sodium amide in the presence of alkali halide salts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1306–1313, June, 1979.     

Ab Initio Structure Investigation of the Enol Forms of β-Diketones RCOCH2COR (R = H, CH3, CF3)

The geometrical parameters, force field parameters, and vibrational frequencies of the enol forms of -diketones RCOCH₂COR (R = H, CH₃, CF₃) were calculated using the ab initio MO LCAO SCF method involving broad bases of Cartesian Gaussian functions. For acetylacetone (R = CH₃), the potential surface of rotation of the two methyl groups was investigated in detail, and the minimal energy route of the transfer of the hydroxyl proton inside the chelate ring was calculated. For hexafluoroacetylacetone (R = CF₃) and malonic dialdehyde (R = H), calculations were carried out only for stationary points on the potential energy surface. For all the geometrical configurations under study, the relative energies were refined with inclusion of electron correlation in terms of second-, third-, and fourth-order Möller–Plesset perturbation theory; for molecules with R = H, CH₃, the configuration interaction procedure taking account of all single and double excitations was additionally employed. The experimental and theoretical data are compared with those available in the literature. The substituent effect on the geometrical and electronic structure of the chelate ring is studied.