A Novel Route to 1,2,4-Triazoles

A novel synthetic method for the synthesis of 1,2,4-triazoles have been described starting from 1,3,4-thiadiazoles by adsorbing on acidic alumina under microwave irradiations (MWI).     

Detailed physicochemical and thermochemical investigation of Upper Assam oil shale

Journal of Thermal Analysis and Calorimetry - The present work provides a detailed characterization and kinetic study of oil shale of Upper Assam, India. The physicochemical characteristics of oil...     

First-principles density functional theory study of generalized stacking faults in TiN and MgO

In this paper, the generalized stacking fault (GSF) energies in different slip planes of TiN and MgO are calculated using highly reliable first-principles density functional theory (DFT) calculations. During DFT calculations, the issue of different ways to calculate the GSF energetics in ceramic materials containing more than one element was addressed and applied. For 〈1?1?0〉/{1?1?1} slip, a splitting of saddle point in TiN was observed. For 〈1?1?2〉/{1?1?1} slip, a stable stacking fault at a₀/3〈1?1?2〉 displacement was formed in TiN. For synchroshear mechanism where the slip was accompanied by a cooperative motion of the interfacial nitrogen atoms within the slip plane, a second stable stacking fault was formed at a₀/6〈1?1?2〉 displacement. The energy barrier for the shuffling of nitrogen atoms from one state to another is calculated to be 0.70 eV per atom. In contrast, such features are absent in MgO. These differences highlight the influence of complex bonding nature (mixed covalent, ionic, and metallic bondings) of TiN, which is substantially different than that in MgO (simple ionic bonding) on GSF shapes.     

On ‘light’ fermions and proton stability in ‘big divisor’ D3/D7 large volume compactifications

Building on our earlier work (Misra and Shukla, Nucl. Phys. B 827:112, 2010; Phys. Lett. B 685:347–352, 2010), we show the possibility of generating “light” fermion mass scales of MeV–GeV range (possibly related to the first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-brane restricted to (in principle) stacks of fluxed D7-branes wrapping the “big” divisor Σ _B . This part of the paper is an expanded version of the latter half of Sect. 3 of a published short invited review (Misra, Mod. Phys. Lett. A 26:1, 2011) written by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, and we estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 10⁶¹ years. Based on GLSM calculations in (Misra and Shukla, Nucl. Phys. B 827:112, 2010) for obtaining the geometric K?hler potential for the “big divisor,” using further the Donaldson’s algorithm, we also briefly discuss in the first of the two appendices the metric for the Swiss-Cheese Calabi–Yau used, which we obtain and which becomes Ricci flat in the large-volume limit.     

Skeletal Rearrangement in the ZnII‐Catalyzed [4+2]‐Annulation of Disubstituted N‐Hydroxy Allenylamines with Nitrosoarenes to Yield Substituted 1,2‐Oxazinan‐3‐one Derivatives

This work reports zinc‐catalyzed [4+2]‐annulation reactions of disubstituted N‐hydroxy allenylamines with nitrosoarenes to afford substituted 1,2‐oxazinan‐3‐ones with a skeletal rearrangement. This annulation is applicable to a reasonable scope of allenylamines and nitrosoarenes. Our control experiments indicate that nitrosobenzene can also implement this annulation through a radical annulation path, but with poor efficiency. Zn(OTf)₂ or AgOTf greatly improves the efficiency of this [4+2]‐annulation; the effect of these metal species is discussed in detail.     

Rotationally-Resolved Excitation Spectroscopy of the Methoxy Radical in a Supersonic Jet

Abstract

Laser-induced fluorescence excitation spectra of the methoxy radical have been obtained under sufficiently high resolution in a supersonic jet expansion. The rotational structure associated with its origin band has been identified in the midst of strong overlapping rotational transitions due to the hydroxyl radical in the 31490–31700 cm^?1 spectral region. Rotationally-resolved A ²A₁ - X ²E spectra of the 0₀ ⁰ band of methoxy have been explicitly assigned using the nomenclature for prolate symmetric top transitions in doublet states.