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51.
Nagarajan Shobana Pandurangan Prakash Antony V. Samrot P. J. Jane Cypriyana Purohit Kajal Mahendran Sathiyasree Subramanian Saigeetha T. Stalin Dhas D. Alex Anand Gokul Shankar Sabesan Bala Sundaram Muthuvenkatachalam Basanta Kumar Mohanty Sridevi Visvanathan 《Molecules (Basel, Switzerland)》2022,27(12)
Plant gums are bio-organic substances that are derived from the barks of trees. They are biodegradable and non-adverse complex polysaccharides that have been gaining usage in recent years due to a number of advantages they contribute to various applications. In this study, gum was collected from Moringa oleifera and Azadirachta indica trees, then dried and powdered. Characterizations of gum polysaccharides were performed using TLC, GC-MS, NMR, etc., and sugar molecules such as glucose and xylose were found to be present. Effects of the gums on Abelmoschus esculentus growth were observed through root growth, shoot growth, and biomass content. The exposure of the seeds to the plant gums led to bio stimulation in the growth of the plants. Poor quality soil was exposed to the gum polysaccharide, where the polysaccharide was found to improve soil quality, which was observed through soil analysis and SEM analysis of soil porosity and structure. Furthermore, the plant gums were also found to have bio-pesticidal activity against mealybugs, which showed certain interstitial damage evident through histopathological analysis. 相似文献
52.
S. Ramasamy D. J. Smith P. Thangadurai K. Ravichandran T. Prakash K. PAdmaprasad V. Sabarinathan 《Pramana》2005,65(5):881-891
The ultra high vacuum chamber was developed in the Department of Nuclear Physics, University of Madras with the funding from
DST, India. This UHV chamber is used to prepare nanocrystalline materials by inert gas condensation technique (IGCT). Nanocrystalline
materials such as PbF2, Mn2+-doped PbF2, Sn-doped In2O3 (ITO), ZnO, Al2O3, Ag2O, CdO, CuO, ZnSe:ZnO etc., were prepared by this technique and characterized. Results of some of these materials will be
presented in this paper. In solid-state207Pb NMR on PbF2 a separate signal due to the presence of grain boundary has been observed. The structural phase transition pressure during
the phase transformation from the cubic phase to orthorhombic phase under high pressure shows an increase with the decrease
in grain size. Presence of electronic centres in nanocrystalline PbF2 is observed from Raman studies and the same has been confirmed by photoluminescence studies. Al2O3 was prepared and56Fe ions were implanted. After implantation segregation of56Fe ions was examined by SEM. The oxidation properties of ITO were studied by HRTEM. As against the expectation of oxide coating
on individual nanograins of In-Sn alloy, ITO nanograins grew into faceted nanograins on heat treatment in air and O2 atmosphere. The growth of ITO under O2 atmosphere showed pentagon symmetry. The PMN was initially prepared by solid-state reaction. Further, this PMN relaxor material
will be used to convert into nanocrystalline PMN by IGCT with sputtering and will be studied 相似文献
53.
Jinesh M. Kuthanapillil A. Nijamudheen Nayana Joseph Praveen Prakash E. Suresh Ayan Datta K.V. Radhakrishnan 《Tetrahedron》2013
A detailed investigation on the effect of solvent polarity, temperature, and microwave irradiation on periselectivity in cycloaddition reactions of pentafulvenes with 3-oxidopyrylium betaine is described. The base catalyzed generation of 3-oxidopyrylium betaine in CHCl3 resulted in the exclusive formation of [6+3] adducts. With increase in solvent polarity and temperature, mixtures of [6+3] and [3+2] adducts were formed, where as under microwave irradiation, [3+2] adducts were formed exclusively. The experimental results have been rationalized on the basis of theoretical calculations. 相似文献
54.
55.
G.K. Surya Prakash Laxman Gurung Philipp Christoph SchmidFang Wang Tisa Elizabeth ThomasChiradeep Panja Thomas MathewGeorge A. Olah 《Tetrahedron letters》2014
Nitroso compounds are versatile reagents in synthetic organic chemistry. Herein, we disclose a feasible protocol for the ipso-nitrosation of aryl boronic acids using chlorotrimethylsilane–sodium nitrite unison as nitrosation reagent system. 相似文献
56.
Samadhan S. Nagane Sachin S. Kuhire Uday A. Jadhav Sushilkumar A. Dhanmane Prakash P. Wadgaonkar 《Journal of polymer science. Part A, Polymer chemistry》2019,57(5):630-640
A bisphenol bearing pendant maleimide group, namely, N‐maleimidoethyl‐3, 3‐bis(4‐hydroxyphenyl)‐1‐isobenzopyrrolidone (PPH‐MA) was synthesized starting from phenolphthalein. Aromatic (co)polyesters bearing pendant maleimide groups were synthesized from PPH‐MA and aromatic diacid chlorides, namely, isophthaloyl chloride (IPC), terephthaloyl chloride (TPC), and 50:50 mol % mixture of IPC and TPC by low temperature solution polycondensation technique. Copolyesters were also synthesized by polycondensation of different molar proportions of PPH‐MA and bisphenol A with IPC. Inherent viscosities and number‐average molecular weights of aromatic (co)polyesters were in the range of 0.52–0.97 dL/g and 20,200–32,800 g/mol, respectively indicating formation of medium to reasonably high‐molecular‐weight polymers. 13C NMR spectral analysis of copolyesters revealed the formation of random copolymers. The 10% weight loss temperature of (co)polyesters was found in the range 470–484 °C, indicating their good thermal stability. A selected aromatic polyester bearing pendant maleimide groups was chemically modified via thiol‐maleimide Michael addition reaction with two representative thiol compounds, namely, 4‐chlorothiophenol and 1‐adamantanethiol to yield post‐modified polymers in a quantitative manner. Additionally, it was demonstrated that polyester containing pendant maleimide groups could be used to form insoluble crosslinked gel in the presence of a multifunctional thiol crosslinker. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 630–640 相似文献
57.
Ikhlas Gadwal Prakash P. Wadgaonkar Amol B. Ichake Shivshankar R. Mane 《Journal of polymer science. Part A, Polymer chemistry》2019,57(2):146-156
A new approach was developed for synthesis of certain A3B3‐type of double hydrophilic or amphiphilic miktoarm star polymers using a combination of “grafting onto” and “grafting from” methods. To achieve the synthesis of desired miktoarm star polymers, acetyl protected poly(ethylene glycol) (PEG) thiols (Mn = 550 and 2000 g mol?1) were utilized to generate A3‐type of homoarm star polymers through an in situ protective group removal and a subsequent thiol–epoxy “click” reaction with a tris‐epoxide core viz. 1,1,1‐tris(4‐hydroxyphenyl)ethane triglycidyl ether. The secondary hydroxyl groups generated adjacent to the core upon the thiol–epoxy reaction were esterified with α‐bromoisobutyryl bromide to install atom transfer radical polymerization (ATRP) initiating sites. ATRP of N‐isopropylacrylamide (NIPAM) using the three‐arm star PEG polymer fitted with ATRP initiating sites adjacent to the core afforded A3B3‐type of double hydrophilic (PEG)3[poly(N‐isopropylacrylamide)] (PNIPAM)3 miktoarm star polymers. Furthermore, the generated hydroxyl groups were directly used as initiator for ring‐opening polymerization of ε‐caprolactone to prepare A3B3‐type of amphiphilic (PEG)3[poly(ε‐caprolactone)]3 miktoarm star polymers. The double hydrophilic (PEG)3(PNIPAM)3 miktoarm star polymers showed lower critical solution temperature around 34 °C. The preliminary transmission electron microscopy analysis indicated formation of self‐assembly of (PEG)3(PNIPAM)3 miktoarm star polymer in aqueous solution. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 146–156 相似文献
58.
59.
Clickable polyurethanes based on s‐triazine ring containing aromatic diisocyanate bearing pendent alkyne group: Synthesis and postmodification 下载免费PDF全文
Kavita Garg Deepshikha Chatterjee Prakash P. Wadgaonkar 《Journal of polymer science. Part A, Polymer chemistry》2017,55(6):1008-1020
A new s‐triazine ring containing aromatic diisocyanate bearing a pendent alkyne group, namely, 2,4‐bis(4‐isocyanatophenoxy)?6‐(prop‐2‐yn‐1‐yloxy)?1,3,5‐triazine was synthesized and reacted with various diols viz., 1,10‐decanediol, tetraethylene glycol and polyethylene glycols in the presence of dibutyltin dilaurate as the catalyst to obtain a series of linear polyurethanes. The selected polyurethanes possessing pendent alkyne groups were postmodified with chemically diverse azides viz., 1‐(azidomethyl)benzene, 1‐(azidomethyl)pyrene, and methoxy end‐caped poly(ethylene glycol) azide via copper‐catalysed azide‐alkyne Huisgen 1,3‐dipolar cycloaddition. FTIR and 1H NMR spectra indicated quantitative click reaction. UV–vis and fluorescence spectroscopic analysis confirmed complete incorporation of pyrenyl groups indicating the formation of fluorescence active polyurethane by postmodification with 1‐(azidomethyl)pyrene. TG analysis of polyurethanes indicated two stage weight loss and their thermal stability, as judged by T 10 values, was governed by weight percent of urethane linkages. The water contact angle measurements revealed improved wettability with increased content of PEG either in the backbone of polyurethanes or as grafted chains. DLS and TEM studies confirmed that certain polyurethanes possessing PEG segments displayed self‐assembly in aqueous solution, which was further supported by pyrene encapsulation studies using UV–vis spectroscopy. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 1008–1020 相似文献
60.
Shivanand Gajare Megha Jagadale Altafhusen Naikwade Prakash Bansode Gajanan Rashinkar 《应用有机金属化学》2019,33(6)
Ferrocene tethered N‐heterocyclic carbene‐copper complex anchored on graphene ([GrFemImi]NHC@Cu complex) has been synthesized by covalent grafting of ferrocenyl ionic liquid in the matrix of graphene followed by metallation with copper (I) iodide. The [GrFemImi]NHC@Cu complex has been characterized by fourier transform infrared (FT‐IR), fourier transform Raman (FT‐Raman), CP‐MAS 13C NMR spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), energy dispersive X‐ray (EDX) analysis, X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area analysis and X‐ray diffractometer (XRD) analysis. This novel complex served as a robust heterogeneous catalyst for the synthesis of bioactive N‐aryl sulfonamides from variety of aryl boronic acids and sulfonyl azides in ethanol by Chan‐Lam coupling. Recyclability experiments were executed successfully for six consecutive runs. 相似文献