New model describing interaction between an electromagnetic wave and a molecule

The expediency of refining some basic concepts of the common theory of interaction between an electromagnetic field and a substance using a quasi-classical model for the phenomena of absorption and emission of energy and Raman scattering (RS) is considered. The use of the time-dependent Schrodinger equation for obtaining the transition probability constants is discussed. A new model that describes the intensities of the RS lines and involves the explicit introduction of the perturbation operator for the RS spectrum is proposed. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 309–318, May–June, 2008.     

Countably Categorical Structures with n-Degenerate Algebraic Closure

We study the class of ω-categorical structures with n-degenerate algebraic closure for some n ε ω, which includes ω-categorical structures with distributive lattice of algebraically closed subsets (see [4]), and in particular those with degenerate (trivial) algebraic closure. We focus on the models of ω-categorical universal theories, absolutely ubiquitous structures, and ω-categorical structures generated by an indiscernible set. The assumption of n-degeneracy implies total categoricity for the first class, stability for the second, and ω-stability for the third.     

The theory of quark confinement

This is the second of the two last papers by V.N. Gribov concluding his 20 year long study of the problem of quark confinement in QCD. In this paper the analytic structure of quark and gluon Green functions is investigated in the framework of the theory of confinement based on the phenomenon of supercritical binding of light quarks. The problem of unitarity in a confining theory is discussed. The write-up remained unfinished and as such it is presented here. The author was planning to emphasise the link between the electroweak and strong interactions, and in particular the r?le of pions (Goldstone bosons) in confinement, to present an explicit solution for bound states, and to write down an analytic model for quark and gluon Green functions corresponding to confinement. Received: 15 February 1999 / Published online: 15 July 1999     

Synthesis and Characterisation of 1‐[9‐(H,Me3Si,Me3Ge,Me3Sn)9‐Fluorenyl]‐3,7,10‐trimethylgermatranes. The Crystal Structure Analysis of 1‐(9‐Fluorenyl)‐3,7,10‐trimethylgermatrane

The title compounds, viz. C₁₃H₈(R)Ge · (OCHMeCH₂)₃N ( 1 : R = H, 2 : R = Me₃Si; 3 : R = Me₃Ge) were prepared as mixtures of diastereomers by the reaction of N(CH₂CHMeOSnAlk₃)₃ ( 7 : Alk = Et; 8 : Alk = Bu) with C₁₃H₈(R)GeBr₃ ( 4 : R = H, 5 : R = Me₃Si; 6 : R = Me₃Ge), respectively. The synthesis of C₁₃H₈(Me₃Sn)Ge · (OCHMeCH₂)₃N ( 13 ) by the reaction of germatrane ( 1 ) with Me₃SnNMe₂ is reported. Identity and structures were established by elemental analyses, ¹H and ¹³C NMR spectroscopy and mass spectrometry. The crystal structure of 1 was determined by X‐ray diffraction methods.     

Pyrene-Benzimidazole Derivatives as Novel Blue Emitters for OLEDs

Three novel small organic heterocyclic compounds: 2-(1,2-diphenyl)-1H-benzimidazole-7-tert-butylpyrene (compound A), 1,3-di(1,2-diphenyl)-1H-benzimidazole-7-tert-butylpyrene (compound B), and 1,3,6,8-tetra(1,2-diphenyl)-1H-benzimidazolepyrene (compound C) were synthesized and characterized for possible applications as blue OLED emitters. The specific molecular design targeted decreasing intermolecular aggregation and disrupting crystallinity in the solid-state, in order to reduce dye aggregation, and thus obtain efficient pure blue photo- and electroluminescence. Accordingly, the new compounds displayed reasonably high spectral purity in both solution- and solid-states with average CIE coordinates of (0.160 ± 0.005, 0.029 ± 0.009) in solution and (0.152 ± 0.007, 0.126 ± 0.005) in solid-state. These compounds showed a systematic decrease in degree of crystallinity and intermolecular aggregation due to increasing steric hindrance, as revealed using powder X-ray diffraction analysis and spectroscopic studies. An organic light-emitting diode (OLED) prototype fabricated using compound B as the non-doped emissive layer displayed an external quantum efficiency (EQE) of 0.35 (±0.04)% and luminance 100 (±6) cd m⁻² at 5.5 V with an essentially pure blue electroluminescence corresponding to CIE coordinates of (0.1482, 0.1300). The highest EQE observed from this OLED prototype was 4.3 (±0.3)% at 3.5 V, and the highest luminance of 290 (±10) cd m⁻² at 7.5 V. These values were found comparable to characteristics of the best pure blue OLED devices based on simple fluorescent small-molecule organic chromophores.     

Side‐chain functionalized liquid crystalline polymers and blends, 6. Phase behavior,structure and magnetic properties of Cu(II) containing liquid crystalline ionomers

The new series of the LC ionomers containing copper ions has been obtained and their phase behavior has been studied. It was shown that at low metal ion concentrations in the LC ionomers (˜2 mol‐%) the induction of the SmA phase is observed. An increase in the copper ion concentration is accompanied by a slight rise in clearing and glass transition temperatures. The magnetic properties of LC ionomers were studied at the first time. It was shown that LC ionomers are antiferromagneties with a strong exchange interaction J = 174–178 cm^–1. Temperature dependencies of the magnetic moment and the magnetic anisotropy are adequately described in the framework of the 1‐D‐Heisenberg linear‐chain model.     

Comparative analysis of structure and temperature behaviour of two copolyamides - regular KEVLAR and statistical ARMOS

In the present investigation X-ray diffraction techniques, DSC and dynamic mechanical relaxation (DMR) methods have been employed to compare the structure and thermal behaviour of Kevlar (“DuPont”, USA) and Armos (Russia) fibers. Our recent studies have indicated that the non-crystalline phase of copolyesters always contains LC smectic structure in addition to some part of the nematic LC mesophase. It turned out that the copolyamides also possess this interesting feature. Moreover, on heating of a semicrystalline copolyester always the second order phase transition from the crystalline state to condis mesophase has been observed, whereas in the case of copolyamides such a transition has the «virtual» character. As was established by other authors both polymers under study reveal the moisture content. The changes in wide angle X-ray scattering of copolyamides under heat treatment were interpreted in terms of desorption of bound water and structural rearrangement in the plane perpendicular to the chain axis involving of the hydrogen bonding between neighboring macromolecules.