scholarly journals Optical Absorption, Kinetics and Thermodynamic Studies of Pr(III) and Nd(III) Ions with N-Acetyl L-Cysteine in Presence of Ca(II) ions

2022 ◽  
Vol 34 (2) ◽  
pp. 272-278
Author(s):  
Thiyam Samrat Singh ◽  
Thiyam David Singh
Keyword(s):  
Activation Energy ◽  
Complex Formation ◽  
Optical Absorption ◽  
Spectroscopic Technique ◽  
Absorption Kinetics ◽  
Intensity Parameter ◽  
Hypersensitive Transition ◽  
Heterobimetallic Complex ◽  
Spectral Bands ◽  
Kinetics And Thermodynamic

Interaction of N-acetyl-L-cysteine (NAC) with Pr3+ (Pr(NO3)3·6H2O) and Nd3+ (Nd(NO3)3·6H2O) ions are studied in presence of Ca2+ (Ca(NO3)3·4H2O) ion in an aqueous and organic solvent by applying the spectroscopic technique for quantitative probe of 4f-4f transition. The complexation was determined by the variation in the intensities of 4f-4f absorption spectral bands and by applying the change of symmetric properties of electronic-dipole known as Judd-Ofelt parameters Tλ (λ = 2,4,6). On the addition of Ca2+ ion in the binary complexation of praseodymium and neodymium with N-acetyl-L-cysteine (NAC) there is an intensification of bands which shows the effect of Ca2+ toward the heterobimetallic complex formation. Other parameters like Slater-Condon (Fk), bonding (b1/2), the Nephelauxetic ratio (β), percentage covalency (δ) are also used to correlate the complexation of metals with N-acetyl-L-cysteine (NAC). With the minor change in coordination around Pr3+ and Nd3+ ions, the sensitivity of 4f-4f bands is detected and further used to explain the coordination of N-acetyl-L-cysteine (NAC) with Pr3+ and Nd3+ in presence of Ca2+. The variation in oscillator strength (Pobs), energy (Eobs) and dipole intensity parameter help in supporting the heterobimetallic complexation of N-acetyl-L-cysteine. In kinetics investigation, the rate of the complexation of both hypersensitive and pseudo-hypersensitive transition is evaluated at various temperature in DMF solvent. The value of the thermodynamic parameters such as ΔHo, ΔSo and ΔGo and activation energy (Ea) also evaluated.

Thermal Degradation of Complexes Derived from Cu (II) Groundnut (Arachis hypogaea) and Sesame (Sesamum indicum) Soaps

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Anju Joram ◽  
Rashmi Sharma ◽  
Arun kumar Sharma
Keyword(s):  
Activation Energy ◽  
Fatty Acid ◽  
Thermal Degradation ◽  
Arachis Hypogaea ◽  
Edible Oils ◽  
Analytical Data ◽  
Spectroscopic Technique ◽  
Sesamum Indicum ◽  
Energy Of Activation ◽  
Significant Information

Abstract The complexes have been synthesized from Cu (II) soaps of groundnut (Arachis hypogaea) and sesame (Sesamum indicum) oils, with ligand containing nitrogen and sulfur atoms like 2-amino-6-methyl benzothiazole. The complexes were greenish brown in color. In order to study TGA, first characterized them by elemental analysis, and spectroscopic technique such as IR, NMR and ESR. From the analytical data, the stoichiometry’s of the complexes have been observed to be 1:1 (metal:ligand). These complexes have been thermally analyzed using TGA techniques to determine their energy of activation. These complexes show three step thermal degradation corresponding to fatty acid components of the edible oils and each complex has three decomposition steps in the range of 439–738 K. Various equations like Coats–Redfern (CR), Horowitz–Metzger (HM) and Broido equations (BE) were applied to evaluate the energy of activation. The values of energy of activation are observed to be in the following order for both copper groundnut benzothiazole (CGB) and copper sesame benzothiazole (CSeB) complexes: CGB > CSeB. CGB is observed to be more stable than CSeB due to its higher activation energy. The above studies would provide significant information regarding the applications of synthesized agrochemicals and their safe removal through parameters obtained in degradation curves and its relation with energy.

Structural, Electrical and Optical Properties of Laser Deposited Thin Films of Srco0.8Fe0.2O3-δ

1994 ◽  
Vol 369 ◽  
Author(s):  
C. Zhang ◽  
H. Deng ◽  
J. Varon ◽  
B. Abeles ◽  
Y. Yang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Optical Properties ◽  
Optical Absorption ◽  
Laser Deposition ◽  
Electrical And Optical Properties ◽  
Thermally Activated ◽  
Characteristic Features

AbstractThin film SrCo0.8Fe0.2O3-δ were made by pulse laser deposition. The electrical conductivity is thermally activated in the temperature 25-500 °C with an activation energy of 0.17-0.19 eV and is temperature independant from 500-800 °C. The optical absorption shows characteristic features which are interpreted qualitatively in terms of a simple band structure diagram.

scholarly journals Mathematical Modelling of Water Absorption Kinetics Using Empirical and Phenomenological Models for Millets

2019 ◽  
Vol 8 (6) ◽  
pp. 1016-1021 ◽  
Keyword(s):  
Activation Energy ◽  
Water Absorption ◽  
Pearl Millet ◽  
Rate Constant ◽  
Finger Millet ◽  
Effective Diffusivity ◽  
Process Time ◽  
Absorption Kinetics ◽  
Experimental Conditions ◽  
Sigmoidal Model

Steeping is one of the major pre-treatment which can reduce anti-nutritional factors without losing dietary fibre and polyphenols unlike in dehulling. In the current study water absorption characteristics of pearl millet and finger millet during steeping at temperature 10°C, 20°C, 30°C, 40°C and 50°C were calculated. Two empirical and one phenomenological model were used to simulate water absorption kinetics. Both the Peleg model and Omoto model were found adequately capable to predict water uptake of pearl millet and finger millet under the designed experimental conditions with regression coefficient more than 0.96. Due to comparatively high variation in grain volume during the hydration process and longer process time, sigmoidal model cannot be utilized for calculation of effective diffusivity and activation energy. Peleg’s rate constant shows an inverse relationship with steeping temperature. The activation energy was calculated by substituting effective diffusivity with reciprocal of Peleg’s rate constant in Arrhenius equation and was found 25.97 kJ/mol and 32.36 kJ/mol respectively for pearl millet and finger millet.

Synthesis, structure, and optical nonlinearity of soluble ternary cadmium copper tellurolate complex [Cd(μ-TeTol)4{Cu(PPh3)2}2] (Tol = 4-tolyl)

2015 ◽  
Vol 70 (5) ◽  
pp. 361-364 ◽  
Author(s):  
Yan-Jing Wang ◽  
Feng Hu ◽  
Ai-Quan Jia ◽  
Hua-Tian Shi ◽  
Qian-Feng Zhang
Keyword(s):  
Optical Absorption ◽  
Nonlinear Optical ◽  
Optical Nonlinearity ◽  
Heterobimetallic Complex ◽  
Nonlinear Optical Absorption ◽  
532 Nm

AbstractReaction of [Me4N]2[Cd(TeTol)4] (Tol = 4-tolyl) with two equivalents of [Cu(PPh3)2NO3] gave a new soluble tellurolate-bridged heterobimetallic complex of [Cd(μ-TeTol)4{Cu(PPh3)2}2] (1) in which two [Cu(PPh3)2]+ fragments are chelated at opposite edges of a tetrahedral [Cd(TeTol)4]2– moiety via the tellurium atoms. Complex 1 is air and optically stable. The nonlinear optical absorption (α2 = 7.4 × 10–4 cm W–1 mol–1) and refraction (n2 = 2.3 × 10–9 cm2 W–1 mol–1) were determined by z-scan techniques with 7 ns pulses at 532 nm.

Evolution of hardness and transmittance in irradiated LiF single crystals at elevated temperatures

1992 ◽  
Vol 7 (10) ◽  
pp. 2833-2839 ◽  
Author(s):  
Hung-Ye Lin ◽  
Yu-Zen Tsai ◽  
Sanboh Lee
Keyword(s):  
Activation Energy ◽  
Optical Absorption ◽  
Single Crystals ◽  
Vickers Hardness ◽  
Elevated Temperatures ◽  
Kinetic Process ◽  
Order Kinetic ◽  
First Order ◽  
Γ Rays ◽  
Two Stages

The evolution of hardness and transmittance of irradiated LiF single crystals at elevated temperatures has been investigated. The Vickers hardness is proportional to φ1/3 where φ is the dosage of γ-rays. The thermal annealing of hardness which is analyzed according to a first-order kinetic process has one stage for φ = 100 KGy and two stages for φ ≥ 250 KGy. For a given dosage, the activation energy of stage I is larger than that of stage II. The transmittance of irradiated LiF crystals is attributed to F, M, R1, and R2 centers. The transmittance decreases with increasing time at the brief durations, then oscillates, and finally increases monotonically. The region in which the transmittance increases monotonically with time is simulated by a second-order kinetic process of the color center. The activation energy of optical absorption was determined. Comparing both activation energies of hardness and optical absorption, we find that the mechanism of the kinetic process for hardness differs from that for optical absorption.

Role of Metal Phthalocyanine in Redox Complex Conductivity of Polyaniline and Aniline Black

1999 ◽  
Vol 03 (07) ◽  
pp. 679-686 ◽  
Author(s):  
FRANCIS P. XAVIER ◽  
ANTO REGIS INIGO ◽  
GEORGE J. GOLDSMITH
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Optical Absorption ◽  
Band Gap ◽  
Copper Phthalocyanine ◽  
Oxidative Polymerization ◽  
Critical Ratio ◽  
Electrical Measurements ◽  
Free Standing

Polyaniline (PA) and aniline black (AB) were prepared in powder form by the chemical method of oxidative polymerization, from which free-standing thin films were obtained by solvent evaporation using N-methyl pyrrolidinone ( NMP ). The thin films contained 2, 4, 6 or 8 wt% AB. Electrical measurements showed that the samples containing 4% AB exhibited the highest photoconductivity of the four concentrations. Thus there appears to be a critical ratio of PA to AB for maximum photoconductivity. Annealing up to 570 K has little effect on the conductivity. Upon adding a small quantity of copper phthalocyanine ( CuPc ) to the PA + AB, the electrical conductivity increased considerably and the optical absorption was extended from the UV to the near IR. The electrical conductivity mechanism is a consequence of a redox process, since AB is the oxidized state of PA and, upon illumination, there is an exchange of charge carriers. The extension of the range of optical absorption upon addition of CuPc is interpreted to suggest that CuPc photosensitizes the material and enhances the carrier transport process in the redox couple. The activation energy from the temperature-dependent conductivity and the band gap from the electrolyte electroreflectance method were determined. The activation energy for 0.4% CuPc is lowest (0.52 eV) and the corresponding band gap is determined to be 3.0 eV. This organic compound could be a good candidate for inexpensive, reliable and efficient solar energy-converting devices.

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