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The present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850°C for 30 min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.

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A convenient synthesis of 1,5-fused 1,2,4-triazoles from readily available N-arylamidines is reported. The reaction is efficiently promoted by chloramine-T to afford the desired products mostly in high yields and in relatively short time, through direct metal-free oxidative N−N bond formation. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities.

ABSTRACT:The possibility of excited-state protomeric shifts in the biologically important molecule, alloxan, is investigated. We have focused on the S 1 and T 1 excited states of alloxan and its hydroxy tautomers. Modifications brought in by excitation on the relative stabilities, activation barriers, and optimized geometries, computed at the MNDO, AM1, and PM3 levels of approximation, have been discussed for both excited electronic states. The absorption and fluorescence spectra for the three tautomers are also discussed. Results show significant changes in the geometries on excitation, although the changes are similar for the singlet and triplet excited states. Though the relative stability orders do not change, the 2-hydroxy tautomer is stabilized, while the 4-hydroxy tautomer gets destabilized on excitation. The excited states are (n, π * ) states, involving the promotion of a nonbonding oxygen lone pair from the CO-CO-CO moiety, which explains why the oxygens of this group become less basic and the 4-hydroxy tautomer gets destabilized on excitation. However, the activation barriers do not reduce significantly on excitation, and this precludes the possibility of ground-or excited-state proton transfer in the gas phase.