Synthesis and characterization of iron(III) complexes of salicylaldehyde 4-methoxybenzoyl hydrazone

107-111lron(lll) complexes of salicylaldehyde 4-methoxybenzoyl hydrazone, (H2smbhon), have been isolated and the reactions of [Fe(smbhon) (Cl) (H2O)]2 with SnCl2 and CH3CN are discussed. These complexes have been characterised by elemental analyses, molar conductance values, magnetic susceptibilities, molecular weights and spectroscopic (electronic,infrared and Mössbauer) data. Depending on the reaction conditions, the ligand may function as a dibasic tridentate, monobasic or neutral bidentate ligand

Synthesis and characterization of iron(III) complexes of diacetylbis- (4-methoxybenzoyl hydrazone)

529-534A few mono- and binuclear iron(III) complexes have been isolated by the reaction of diacetylbis( 4-methoxybenzoyl hydrazone), H2dambhon with iron salts under varied reaction conditions. Some reactions of [(dambhon)Fe(Cl)(H2O)].4H2O, isolated in this study, with acetylacetone, pyridine, SnCl2 and PPh3 have been carried out which afforded new iron(III) complexes. The new complex [(dambhon)Fe(PPh3)Cl], thus prepared, smoothly reacts with thiomethanol, N-trimethylsilyldimethylamine, benzyltrimethylsilane, and p-bis(trimethylsilylmethyl)benzene leading to the isolation of several new iron(III) and organoiron(III) compounds.. The complexes are characterized on the basis of elemental analyses, molar conductance, molecular weight, magnetic susceptibilities and spectroscopic (electronic, IR and Mössbauer) data. The ligand H2 dambhon in these complexes functions as a NNOO donor either as a mono- or dianion or neutral ligand

Size-Dependent Conformational Features of Aβ_17–42 Protofilaments from Molecular Simulation Studies

Alzheimer’s disease is caused due to aggregation of amyloid beta (Aβ) peptide into soluble oligomers and insoluble fibrils in the brain. In this study, we have performed room temperature molecular dynamics simulations to probe the size-dependent conformational features and thermodynamic stabilities of five Aβ_17–42 protofilaments, namely, O₅ (pentamer), O₈ (octamer), O₁₀ (decamer), O₁₂ (dodecamer), and O₁₄ (tetradecamer). Analysis of the free energy profiles of the aggregates showed that the higher order protofilaments (O₁₀, O₁₂, and O₁₄) undergo conformational transitions between two minimum energy states separated by small energy barriers, while the smaller aggregates (O₅ and O₈) remain in single deep minima surrounded by high barriers. Importantly, it is demonstrated that O₁₀ is the crossover point for which the twisting of the protofilament is maximum, beyond which the monomers tend to rearrange themselves in an intermediate state and eventually transform into more stable conformations. Our results suggest that the addition of monomers along the axis of an existing protofilament with a critical size (O₁₀ according to the present study) proceeds via an intermediate step with relatively less stable twisted structure that allows the additional monomers to bind and form stable larger protofilaments with minor rearrangements among themselves. More importantly, it is demonstrated that a combination of twist angle and end-to-end distance can be used as a suitable reaction coordinate to describe the growth mechanism of Aβ protofilaments in simulation studies

<span style="font-size:12.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language: EN-IN;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Synthesis and charaterisation of cobalt complexes of salicylaldehyde 4-methoxybenzoyl hydrazone (H₂ smbhon)</span>

1139-1144A number of mononuclear and dinuclear cobalt(II) and cobalt(III) complexes have been isolated by reacting salicylaldehyde 4- methoxybenzoyl hydrazone (H2smbhon) with CoCI2.6H2O, CO(NO3)26H2O, Co(CH3COO)2.4H2O and Co(acac)3 under varied reaction conditions. [CoII(smbhon)(H2O)3], isolated in this study, further reacts with pyridine (Py) dipyridine (dip) and triphenylphosphine (Ph3P) in presence of NaCIO4 to form new cobalt(III) complexes. Equimolar mixtures of [CoII(smbhon)(H2O)3] and the ligands like acetylacetone (Hacac), glycine (Hgly), N,N-bisethyleneacteophenoneimine (bape),N-phenylsalicylaldimine (Haslan), N-phenylorthohydroxyacetophenoneimine (Hohapan), N-hydroxymethylsalicylaldimine (H2salgly), N-2-hydroxyphenylsalicylaldimine (H2saloap) or N-2-carboxyphenylsalicylaldimine (H2salana) on refluxing in methanol-acetonitrile in the presence of oxygen at pH ~ 9 afford coloured heterochelates of cobalt (III) in high yields. Structures of the complexes have been assigned on the basis of elemental analyses, molecular weights, molar conductances, magnetic moments and spectral (UV -vis and IR) studies. The physico-chemical data suggest that H2smbhon can behave as a dibasic tridentate (ONO) donor, monobasic tridentate (ONO) (keto form) donor and monobasic bidentate (NO) donor depending on the reaction conditions

Application of Oil Condition Monitoring Techniques for Improving Critical Equipment Availability in Steel Plant

The particles contained in the lubricating oil carry detailed and important information about the condition of the machine. The information may be deduced from particle shape, composition, size distribution and concentration. Particles eroded from the surface of an oil wetted component in any centralized lubrication system upon examination give specific and accurate information. The operating wear modes prevailing in the machine are determined with the examination of the lubricant in circulation. Analytical and experimental studies were undertaken to assess the deleterious effect of contaminants present in lubricant on the performance of critical equipment in steel plant. The study involves the findings of typical characteristics developed in the oil wetted components on account of contaminants. Morphology of worn out particles, change in chemistry of lubricant and the presence of contaminants in the centralized system was optimized. The experimental methods include quantification of total ferromagnetic particles through direct reading and analytical ferrography, particle size in a laser diffraction particle counter and deleterious particles present in the lubricant through an Oil View Analyser instrument and an inductive couple plasma unit. The above condition based analytical techniques were used to predict the overall health of the critical equipment located in different units of steel plant

Effects of a Solar Eclipse on the Propagation of VLF-LF Signals: Observations and Results

The results from the measurements of some of the fundamental parameters (amplitude of sferics and transmitted signal, conductivity of lower ionosphere) of the ionospheric responses to the 22 July 2009 solar eclipse (partial: 91.7%) are shown. This study summarizes our results from sferics signals at 81 kHz and subionospheric transmitted signals at 19.8 and 40 kHz recorded at Agartala, Tripura (latitude: 23¢XN, longitude: 91.4¢XE). We observed significant absorption in amplitude of these signals during the eclipse period compared to their ambient values for the same period during the adjacent 7 days. The signal strength along their propagation paths was controlled by the eclipse associated decrease in ionization in the D-region of the ionosphere. Waveguide mode theory calculations show that the elevation of the height of lower ionosphere boundary of the Earth-ionosphere waveguide to a value where the conductivity parameter was 106 unit. The absorption in 81 kHz sferics amplitude is high compared to the absorption in the amplitude of 40 kHz signal transmitted from Japan. The simultaneous changes in the amplitudes of sferics and in the amplitude of transmitted signals assert some sort of coupling between the upper atmosphere and the Earth¡¦s near-surface atmosphere prevailing clouds during solar eclipse

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Not AvailablePresent study is a maiden attempt to assess net ecosystem exchange (NEE) of carbon dioxide ( CO2) flux from jute crop (Corchorus olitorius L.) in the Indo-Gangetic plain by using open-path eddy covariance (EC) technique. Diurnal variations of NEE were strongly influenced by growth stages of jute crop. Daytime peak NEE varied from − 5 μmol m− 2 s− 1 (in germination stage) to − 23 μmol m− 2 s− 1 (in fibre development stage). The ecosystem was net CO2 source during nighttime with an average NEE value of 5–8 μmol m− 2 s− 1. Combining both daytime and nighttime CO2 fluxes, jute ecosystem was found to be a net CO2 sink on a daily basis except the initial 9 days from date of sowing. Seasonal and growth stage-wise NEEs were computed, and the seasonal total NEE over the jute season was found to be − 268.5 gC m− 2 (i.e. 10.3 t CO2 ha- 1). In different jute growth stages, diurnal variations of NEE were strongly correlated (R2 > 0.9) with photosynthetic photon flux density (PPFD). Ecosystem level photosynthetic efficiency parameters were estimated at each growth stage of jute crop using the Michaelis–Menten equation. The maximum values of photosynthetic capacity (Pmax, 63.3 ± 1.15 μmol CO2 m− 2 s− 1) and apparent quantum yield (α, 0.072 ± 0.0045 μmol CO2 μmol photon− 1) were observed during the active vegetative stage, and the fibre development stage, respectively. Results of the present study would significantly contribute to understanding of the carbon flux from the Indian agroecosystems, which otherwise are very sparse.Not Availabl