Sweta Mishra

Use of Graphite Oxide and Graphene Oxide as Catalysts in the Synthesis of Dipyrromethane and Calix(4)pyrrole

Graphite oxide and graphene oxides have been used as solid catalysts for the synthesis of 5,5-dialkyldipyrromethanes and calix[4]pyrroles in organic and aqueous solutions at room temperature.

Challenges with Mosquito-borne Viral Diseases: Outbreak of the Monsters

BACKGROUND The viruses responsible for mosquito-borne diseases are on an exploring mode, expanding their horizon, adapting to the situation and comfortably making their presence felt globally, from South Africa to Asia, Europe and United States. The current global scenario and recent documentations indicate towards the real monsters, outbreak of Zika, dengue and chikungunya viruses. Zika, dengue and chikungunya viruses are positive sense single-stranded RNA arbovirus and so their initial symptoms are almost 80% similar and all three are spread by mosquitos which bite during the day. Zika virus may damage brain by targeting the neuron cells in babies, and thereby it is very perilous to pregnant women. Dangerous Type: A less common but highly dangerous type of dengue is one which causes haemorrhagic fever and shock syndrome which are lethal. Chikungunya is not as lethal as Zika and dengue are, but it triggers joints pain which could last for months and even for years. CONCLUSION The vaccines against Zika, dengue and chikungunya viruses are at different stages of development. The challenges associated with the epidemic wave of Zika, dengue and chikungunya viruses have been explained and the current status of drug/ vaccine development against these viruses has been reviewed.

Sulfonated graphenes catalyzed synthesis of expanded porphyrins and their supramolecular interactions with pristine graphene

AbstractA newer synthesis of sulfonic acid functionalized graphenes have been developed, which have been characterized, examined as heterogeneous solid acid carbocatalyst in the synthesis of selected expanded porphyrins in different reaction conditions. This environment-friendly catalyst avoids the use of toxic catalysts and enhances the yields of porphyrinoids. The non-covalent interaction of porphyrinoids has also been studied with exfoliated graphene solution in organic solvents by UV-Visible and fluorescence spectroscopy. Graphical AbstractReaction of pyrrole with arylaldehydes catalyzed by newly synthesized sulfonated graphene in ortho-dichlorobenzene gave 5,10,15,20-tetraarylporphyrins and corresponding expanded porphyrins depending upon the reaction conditions. The possible non-covalent interactions with porphyrinoids with prisitine graphene have been examined by UV-visible and fluorescence spectroscopy.

Applications of laser Raman and FT-IR techniques to leprology, neurology, bacteriology and traumatology

The application of Fourier transform infrared spectroscopy and laser Raman spectroscopy for obtaining structural information about the subtle changes occurring at the molecular level following leprosy, pulmonary tuberculosis, infected burns, epilepsy and Duchenne muscular dystrophy (DMD) are reported in this paper. It is shown that IR spectra exhibit specific signals for each disease. Results of the observed bands of hemoproteins are compared with those of normals. Raman spectra of IgG reveal that alpha-helical conformations are introduced partially in case of the proliferation ofMycobacterium leprae. These results are supported by our IR studies. Typical signals of perturbed stretching region are seen in the pulmonary tuberculosis cases. Disappearance of a few normal bands and strong peaks in the hydrocarbon region characterizes epileptic disorder. Perturbations in the Raman spectra of erythrocyte ghosts are identified following gram-negativePseudomonas aeruginosa infection. Investigations of pathological changes following the onset of body disorders at the molecular level are reported using IR and Raman spectroscopic techniques.

Guanidino-Graphene Catalysed Synthesis of Flavones via Aldol-Michael-Oxidation

Guanidino-graphene has been synthesized by the reaction of bromoamine with reduced graphene oxide and characterized by FT-IR, Raman, TGA, powder XRD, TEM, SEM, and zeta potential. It is a cheap, heterogeneous and environmentally benign solid base catalyst used for cascade Aldol-Michael-oxidation in the synthesis of chalcone, flavonoids.

ELECTRICAL AND OPTICAL NONLINEARITY IN VACUUM-DEPOSITED THIN FILMS OF POLY[N-(4-BENZOYLPHENYL)-2-METHYLACRYLAMIDE]

A new optically nonlinear material, poly[N-(4-benzoylphenyl)-2-methylacrylamide], for conversion of wavelength 1064 nm to 532 nm has been synthesized. The material possesses strong electrical and optical nonlinearity required for second harmonic generation (SHG). The thin films of poly[N-(4-benzoylphenyl)-2-methylacrylamide] were prepared by the vacuum-deposition technique. The optical UV-visible, IR, NMR studies, mass spectrometry, surface topography and nonlinear optical properties of the thin films were studied. The vacuum-deposited thin films of the polymer were subjected to optimized high potential multi-point corona poling at temperatures just below the glass transition temperature (Tg) to create directional orientation of the side chain groups. The optical UV-visible absorption indicates a complete transparency in the visible and IR regions with an absorption peak at ~350 nm. The energy band gap of the polymer was estimated to be ~2.9 eV, from the optical absorption spectra of the thin films. The electrical current–voltage (IV) and optical nonlinear characteristic indicate the strong potential of these polymeric thin films for nonlinear optical (NLO) applications.