Synthesis of 6‐Aminopropyl‐6H‐indolo[2,3‐b]quinoxaline Derivatives

A series of 6‐(3‐aminopropyl)‐6H‐indolo[2,3‐b]quinoxalines were synthesized with high yields by the reaction of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline and corresponding amines in presence of tetrabutylammonium iodide in boiling toluene or dimethylformamide at room temperature. It was found that boiling of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline in acetone with sodium iodide or in acetic acid lead to intramolecular cyclization product.     

Electrical control of ferromagnetic state

We report experiments where magnetization in GaMnAs ferromagnetic semiconductor is manipulated via strain or electric current. In both cases, charge carrier holes become partially polarized due to the anisotropic modification of holes spectra caused by spin–orbit interactions, and this polarization exerts spin torque sufficient to rotate ferromagnetic domains.     

2.1 Tesla permanent-magnet Faraday isolator for subkilowatt average power lasers

A Faraday isolator with one magneto-optical element providing 31 dB isolation ratio for 330 W average power lasers was produced and investigated in an experiment. These remarkable parameters were achieved by increasing the magnetic field and using a [0 0 1] oriented TGG crystal.     

On diversity and stability of unit bases for the Euclidean metric

We prove the existence of a family Ω(n) of 2 ^c (where c is the cardinality of the continuum) subgraphs of the unit distance graph (E ⁿ , 1) of the Euclidean space E ⁿ , n ≥ 2, such that (a) for each graph G ? Ω(n), any homomorphism of G to (E ⁿ , 1) is an isometry of E ⁿ ; moreover, for each subgraph G ₀ of the graph G obtained from G by deleting less than c vertices, less than c stars, and less than c edges (we call such a subgraph reduced), any homomorphism of G ₀ to (E ⁿ , 1) is an isometry (of the set of the vertices of G ₀); (b) each graph G ? Ω(n) cannot be homomorphically mapped to any other graph of the family Ω(n), and the same is true for each reduced subgraph of G.     

Thiazolidine-2,4-dione in benzoylation reaction

Chemistry of Heterocyclic Compounds - The direction of the benzoylation reaction of thiazolidine-2,4-dione under the conditions of basic and general acid catalysis was studied. It was shown that...     

Frequency-degenerate nonlinear light scattering in low-symmetry crystals

A considerable distinction of light-induced scattering in optically biaxial crystals comes from the fact that the principal axes of the optical indicatrix do not coincide with the crystallographic directions. The study of photorefractive scattering in Sn2P2S6 (monoclinic symmetry) revealed the particular requirements as to light polarization for excitation of parametric scattering and the polarization inhomogeneity of wide-angle scattering.     

Polymeric Semiconductors with a Pre‐Specified Alternation of Conjugated Bonds and Metal Clusters

Summary: In this work the first samples of polymeric semiconductors of a new structure are produced. Their electric conductivity is of the order ∼10⁻² Ohm⁻¹ · cm⁻¹ and it increases with temperature. Their synthesis includes a stage of radiation grafting of a matrix‐type on stretched polyamide films. Conducting molecular circuits in such materials include fragments with conjugated bonds and metal clusters. The alternation of these fragments is determined by the polyamide matrix.

Plot of voltage versus current determined for new polymer semiconducting films where fragments with conjugated bonds alternate with silver clusters.     

Reaction of ω‐carbonyl substituted 1,3,3‐trimethyl‐2‐methyleneindolines with phosphorus(III) halides

The phosphorylation of N‐benzoyl‐2‐(1,3,3‐trimethyl‐2‐methyleneindoline)acetamide ( 2 ) and ω‐(3‐dimethylamino)benzoyl‐1,3,3‐trimethyl‐2‐methyleneindoline ( 6 ) with phosphorus(III) halides resulted in the formation of 2,3‐dihydro‐4H‐1,5,2‐oxazaphosphinin‐4‐one and 1,2‐dihydro‐3H‐phosphindol‐3‐one systems, respectively. The properties of the obtained compounds were studied. Further cyclization of 1,2‐dihydro‐3H‐phosphindol‐3‐one into dihydrophosphindolo[3,2‐c]pyrazole was carried out. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:23–28, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10060     

Effect of spatial heterogeneity on level of rejuvenation in Ni80P20 metallic glass

Understanding the relation between spatial heterogeneity and structural rejuvenation is one of the hottest topics in the field of metallic glasses (MGs). In this work, molecular dynamics (MD) simulation is implemented to discover the effects of initial spatial heterogeneity on the level of rejuvenation in the Ni$_{80}$P$_{20 }$MGs. For this purpose, the samples are prepared with cooling rates of $10^{10}$ K/s-$10^{12}$ K/s to make glassy alloys with different atomic configurations. Firstly, it is found that the increase in the cooling rate leads the Gaussian-type shear modulus distribution to widen, indicating the aggregations in both elastically soft and hard regions. After the primary evaluations, the elastostatic loading is also used to transform structural rejuvenation into the atomic configurations. The results indicate that the sample with intermediate structural heterogeneity prepared with 10$^{11}$ K/s exhibits the maximum structural rejuvenation which is due to the fact that the atomic configuration in an intermediate structure contains more potential sites for generating the maximum atomic rearrangement and loosely packed regions under an external excitation. The features of atomic rearrangement and structural changes under the rejuvenation process are discussed in detail.