03201nas a2200289 4500008004100000022001400041245009400055210006900149260006700218300001400285490000700299520215700306653000602463653001602469653005502485653002202540653002702562653004802589653001802637653003602655653002402691653003102715653001202746100001502758700001602773856012202789 2005 eng d a0887-624X00aNovel tridentate nitrogen donor as ligand in copper catalyzed ATRP of methyl methacrylate0 aNovel tridentate nitrogen donor as ligand in copper catalyzed AT a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcNOV a4996-50080 v433 a

A tridentate ligand, BPIEP: 2,6-bis[1-(2,6-diisopropyl phenylimino) ethyl] pyridine, having central pyridine unit and two peripheral imine coordination sites was effectively employed in controlled/''living'' radical polymerization of MXU at 90 degrees C in toluene as solvent, (CuBr)-Br-I as catalyst, and ethyl-2-bromoisobutyrate (EBiB) as initiator resulting in well-defined polymers with polydispersities M-W/M-n <= 1.23. The rate of polymerization follows first-order kinetics, k(app) = 3.4 x 10(-5) s(-1), indicating the presence of low radical concentration ([P*] <= 10(-8)) throughout the reaction. The polymerization rate attains a maximum at a ligand-to-metal ratio of 2:1 in toluene at 90 degrees C. The solvent concentration (v/v, with respect to monomer) has a significant effect on the polymerization kinetics. The polymerization is faster in polar solvents like, diphenylether, and anisole, as compared to toluene. Increasing the monomer concentration in toluene resulted in a better control of polymerization. The molecular weights (M-n,M-SEC) increased linearly with conversion and were found to be higher than predicted molecular (M-n,M-Cal). However, the polydispersity remained narrow, i.e., <= 1.23. The initiator efficiency at lower monomer concentration approaches a value of 0.7 in 110 min as compared to 0.5 in 330 min at higher monomer concentration. The aging of the copper salt complexed. with BPIEP had a beneficial effect and resulted in polymers with narrow polydispersitities and higher conversion. PMMA obtained at room temperature in toluene (33%, v/v) gave PDI of 1.22 (Mn = 8500) in 48 h whereas, at 50 degrees C the PDI is 1.18 (Ma = 10,300), which is achieved in 23 h. The plot of In kapp versus 1/T gave an apparent activation energy of polymerization as (Delta E-app(not equal)) 58.29 KJ/mol and enthalpy of equilibrium (Delta H-eq(0)) to 28.8 KJ/mol. Reverse ATRP of MMA was successfully performed using AIBN in bulk as well as solution. The controlled nature of the polymerization reaction was established through kinetic studies and chain extension experiments. (c) 2005 Wiley Periodicals, Inc.

10a210a6-bis [1-(210a6-diisopropyl phenylimino) ethyl] pyridine (BPIEP)10aActivation energy10aapparent rate constant10aAtom transfer radical polymerization (ATRP)10adiphenylether10aethyl-2-bromoisobutyrate (EBiB)10amethyl methacrylate10apolydispersity index (PDI)10aToluene1 aMittal, A.1 aSivaram, S. uhttps://library.ncl.res.in/content/novel-tridentate-nitrogen-donor-ligand-copper-catalyzed-atrp-methyl-methacrylate-102001nas a2200253 4500008004100000022001400041245008300055210006900138260006800207300001200275490000700287520113000294653002201424653001601446653002201462653002101484653001501505100002501520700002001545700002201565700001801587700002501605856011701630 2005 eng d a0021-899500aThermal degradation kinetics of polyesters containing mesogenic aromatic diols0 aThermal degradation kinetics of polyesters containing mesogenic  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcAUG a784-7920 v973 a

A series of polyesters were synthesized by reacting structurally differing aromatic diols with either saturated (flexible) or unsaturated (rigid) dicarboxylic acid halide by a stirred interfacial polycondensation technique. Thermal degradation kinetics of these polyesters were investigated by applying Coats-Redfern and Horowitz-Metzger nonisothermal procedures. The dynamic thermogravimetry experiments were conducted in nitrogen to obtain differential thermogravimetric plots. Thermal stability of these polyesters was discussed on the basis of semiquantitative methods such as differential procedural decomposition temperature, integral procedural decomposition temperature, and fraction decomposition temperature (e.g., 10 % DT). Degradation proceeded in multiple stages. The thermal degradation patterns and activation energies in these stages were discussed in relation to central bridging moieties of aromatic diol. The activation energies of these polyesters were found to be in the range of 100 to 200 kJ/mol. The effect of spacer type on activation energy was also reported. (c) 2005 Wiley Periodicals, Inc.

10aActivation energy10aDegradation10akinetics (polym.)10aPolycondensation10apolyesters1 aMule, Smita, Atmaram1 aGhadage, R., S.1 aJacob, Nalini, E.1 aRajan, C., R.1 aPonrathnam, Surendra uhttps://library.ncl.res.in/content/thermal-degradation-kinetics-polyesters-containing-mesogenic-aromatic-diols-002127nas a2200229 4500008004100000022001400041245016000055210006900215260006800284300001400352490000700366520120600373653002201579653001901601653002901620653001301649653002201662653002701684100002901711700002501740856013201765 2007 eng d a0887-624X00aKinetics of hexene-1 polymerization using [(N,N `-diisopropylbenzene)-2,3-(1,8-napthyl)-1,4-diazabutadiene] dibromonickel/methylaluminoxane catalyst system0 aKinetics of hexene1 polymerization using NN diisopropylbenzene23 a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAR a1093-11000 v453 a

{Kinetics of hexene-1 polymerization was investigated using [(N,N'-diiso-propylbenzene)2,3-(1,8-napthly)-1,4-diazabutadiene]/dibro monickel/methylaluminoxane catalyst. Experiments were performed at varying catalyst and monomer concentrations in the temperature range of -10 to 35 degrees C. First order time-conversion plot shows a downward curvature at temperatures of 20 degrees C and 35 degrees C indicating the presence of finite termination reactions. A nonlinear plot of degree of polymerization (P-n) with respect to conversion indicates occurrence of transfer reactions and slow initiation. The experimental molar masses are higher than predicted, which implies that a fraction of catalyst species could not be activated or is deactivated at the early stages of the reactions. The efficiency of the catalyst (Cat(eff)) varies from 0.77 to 0.89. The observed polydispersity of the poly(hexene-1) s is in the range of 1.18-1.48. The reaction order was found to be 1.11 with respect to catalyst. The Arrhenius plot obtained using the overall propagation rate constant, k(p), at five different temperatures (-10, 0, 10, 20, and 35 degrees C) was found to be linear with an activation energy

10aActivation energy10achain transfer10adegree of polymerization10ahexene-110akinetics (polym.)10anickel (alpha-diimine)1 aSubramanyam, Ummadisetty1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/kinetics-hexene-1-polymerization-using-nn-diisopropylbenzene-23-18-napthyl-14-diazabutadiene01978nas a2200229 4500008004100000022001400041245011200055210006900167260007300236300001200309490000700321520111200328653002201440653002501462653003001487653000901517653001401526100002301540700003201563700002701595856012601622 2013 eng d a0141-813000aBiochemical characterization of recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala0 aBiochemical characterization of recombinant cinnamoyl CoA reduct aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a154-1590 v583 a

Recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) protein from Leucaena leucocephala was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. Optimum pH for forward and reverse reaction was found to be 6.5 and 7.8 respectively. The enzyme was most stable around pH 6.5 at 25 degrees C for 90 min. The enzyme showed k(cat)/k(m) for feruloyl, caffeoyl, sinapoyl, coumaroyl CoA, coniferaldehyde and sinapaldehyde as 4.6, 2.4, 2.3, 1.7, 1.9 and 1.2 (x10(6) M-1 s(-1)), respectively, indicating affinity of enzyme for feruloyl CoA over other substrates and preference of reduction reaction over oxidation. Activation energy, E-a for various substrates was found to be in the range of 20-50 kJ/mol. Involvement of probable carboxylate ion, histidine, lysine or tyrosine at the active site of enzyme was predicted by pH activity profile. SAXS studies of protein showed radius 3.04 nm and volume 49.25 nm(3) with oblate ellipsoid shape. Finally, metal ion inhibition studies revealed that Ll-CCRH1 is a metal independent enzyme. (C) 2013 Elsevier B.V. All rights reserved.

10aActivation energy10aCinnamoyl CoA esters10aCinnamoyl CoA reductase 110aSAXS10astability1 aSonawane, Prashant1 aVishwakarma, Rishi, Kishore1 aKhan, Bashir, Mohammad uhttps://library.ncl.res.in/content/biochemical-characterization-recombinant-cinnamoyl-coa-reductase-1-ll-ccrh1-leucaena-002798nas a2200229 4500008004100000245010000041210006900141260000900210300001600219490000600235520205700241653002202298653002002320653002102340653000802361653001402369653000802383100001902391700001802410700001902428856012102447 2026 eng d00aNanostructured Fe-ZIF supported on ni foam as electrocatalyst for the oxygen evolution reaction0 aNanostructured FeZIF supported on ni foam as electrocatalyst for cJUL  a12921-129360 v93 a

Developing and constructing highly stable and active electrocatalysts for the water oxidation or oxygen evolution reaction (OER) remains critical for achieving efficient water splitting. Herein, we report the in situ transformation of iron-cobalt hydroxycarbonate directly grown on nickel foam (NF) into nanostructured Fe0.2ZIF(67 + 9)/NF via a ligand-engineering strategy using a solvothermal approach. Post-OER characterization reveals a slight increase in oxygen content, suggesting surface reconstruction during electrochemical operation. The obtained Fe0.2ZIF(67 + 9)/NF exhibits outstanding catalytic performance, revealed in a low overpotential value of only 250 mV to reach the current density of 50 mA cm-2 with a small Tafel slope of 60 mV dec-1, indicative of accelerated reaction kinetics and favorable charge-transfer characteristics. Moreover, the electrochemically active surface area (ECSA) taken before and after 100 C-V cycles shows a 6.5% increase, indicating a structural activation, which is supported by an enhancement of anodic charge by about 13% as compared to Fe0.2ZIF-9/NF. Furthermore, just a 2 mV increase in potential after a 24 h chronopotentiometry test and a 37 mV decrease to sustain 25 mA cm-2 current density depicted the high stability and surface activation in Fe0.2ZIF(67 + 9)/NF. The enhanced catalytic efficiency is further supported by activation energy calculations, confirming improved reaction energetics. Moreover, from the Tafel slope analysis, the K H/K D ratio was calculated, which comes to about 0.42, suggesting a strong inverse kinetic isotopic effect, indicating that proton transfer is not involved in the rate-determining step and that O-H bond cleavage does not control the reaction kinetics. Overall, this study highlights ligand engineering as an effective strategy to regulate structural transformation and surface reconstruction, offering a promising pathway for the rational design of advanced nanostructured ZIF-based electrocatalysts for efficient and durable water oxidation.

10aActivation energy10aelectrocatalyst10ahydroxycarbonate10aKIE10astability10aZIF1 aPrakash, Satya1 aNagar, Harsha1 aSingh, Archana uhttps://library.ncl.res.in/content/nanostructured-fe-zif-supported-ni-foam-electrocatalyst-oxygen-evolution-reaction