Fe3O4@SiO2–ZrCl2‐MNPs: A novel magnetic catalyst for the clean and efficient cascade synthesis of 1‐(benzothiazolylamino)methyl‐2‐naphthol derivatives in the absence of solvent

A green, simple and eco‐friendly three‐component condensation for the synthesis of 1‐(benzothiazolylamino)methyl‐2‐naphthols using new magnetic nanoparticles formulated as Fe₃O₄@SiO₂–ZrCl₂‐MNPs is described. Considering the economic and environmental aspects, the method provides some advantages such as clean procedure, solvent‐free conditions, simple operation and work‐up, relatively short reaction times and high yields of the products. Moreover the introduced catalyst can be readily recovered up to 4 consecutive runs with consistent activity using an external magnet.     

The Bochner-Schoenberg-Eberlein Property for L^{1}(\mathbb{R}^{+})

The classical Bochner-Schoenberg-Eberlein theorem characterizes the continuous functions on the dual group of a locally compact abelian group G which arise as Fourier-Stieltjes transforms of elements of the measure algebra M(G) of G. This has led to the study of the concept of a BSE-algebra as introduced by Takahasi and Hatori in 1990. In the present paper we establish affirmatively a question raised by Takahasi and Hatori that whether $L^{1}({\mathbb{R}}^{+})$ is a BSE-algebra.     

A Simple and Eco-Compatible One-Pot Synthesis of New Symmetrical Dithiocarbamate Podands and Their Dynamic NMR Studies

Abstract

A simple and eco-compatible synthesis of podands as 4_a-i is performed using amines (3_a-c ), CS₂, and dichlordiamides (DCDs) (2_{a, c} ) in the absence of a catalyst in water. Three reacting DCDs (2_a-c ) were obtained in the reaction of aromatic diamines (1_{a, c} ) with chloroacetyl chloride. Dynamic NMR spectroscopic data of three series of podands (4_a-c , 4_d-f , and 4_g-i ) are discussed and their free energies of activations are calculated (ΔG ^≠ _c s) at coalescence temperatures. The ΔG ^≠ _c of these podands were attributed to conformational isomerization in the range of 14.7–17 kcal/mol due to rotation and resonance effects about the thioamide C?N bond.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures.]     

Magnetic Properties of TlCo2Se2 Studied by Mössbauer Spectroscopy

Hyperfine Interactions - The quasi two-dimensional antiferromagnetic compound TlCo2Se2 has been studied by 57Fe Mössbauer spectroscopy. Small single crystals have been made with 2% Fe doping....     

Global anomalies on orbifolds

We consider global anomalies for heterotic string theory formulated on orbifolds. The vanishing of certain characteristic classes in group cohomology provides sufficient conditions for the absence of global anomalies. For abelian orbifolds level matching implies these cohomology conditions, so suffices for the absence of anomalies. For nonabelian orbifolds level matching does not suffice, and there are additional constraints. We give some examples to illustrate these new constraints.The first author is partially supported by an NSF Postdoctoral Research Fellowship. The second author is supported in part by the NSF contract no. PHY 82-15249, and in part by a fellowship from the Harvard Society of Fellows     

Inflation Driven by q-de Sitter

We propose a generalised de Sitter scale factor for the cosmology of early and late time universe, including single scalar field is called as inflaton. This form of scale factor has a free parameter q is called as nonextensivity parameter. When q = 1, the scale factor is de Sitter. This scale factor is an intermediate form between power-law and de Sitter. We study cosmology of such families. We show that both kinds of dark components, dark energy and dark matter simultaneously are described by this family of solutions. As a motivated idea, we investigate inflation in the framework of q-de Sitter. We consider three types of scenarios for inflation. In a single inflation scenario, we observe that, inflation ended without any specific ending inflation ?_end, the spectral index and the associated running of the spectral index are n_s ? 1 ～ ?2??, α_s ≡ 0. To end the inflation: we should have \(q=\frac {3}{4}\). We deduce that the inflation ends when the evolution of the scale factor is a(t) = e_3/4(t). With this scale factor there is no need to specify ?_end. As an alternative to have inflation with ending point, We will study q-inflation model in the context of warm inflation. We propose two forms of damping term Γ. In the first case when Γ = Γ₀, we show the scale invariant spectrum, (Harrison-Zeldovich spectrum, i.e. n_s = 1) may be approximately presented by (\(q=\frac {9}{10},~~N=70\)). Also there is a range of values of R and n_s which is compatible with the BICEP2 data where \(q=\frac {9}{10}\). In case Γ = Γ₁V(?), it is observed that small values of a number of e-folds are assured for small values of q parameter. Also in this case, the scale-invariant spectrum may be represented by \((q,N) = (\frac {9}{10},70)\). For \(q=\frac {9}{10}\) a range of values of R and n_s is compatible with the BICEP2 data. Consequently, the proposal of q-de Sitter is consistent with observational data. We observe that the non-extensivity parameter q plays a significant role in inflationary scenario.