scholarly journals Physical, Optical, and Spectroscopic Studies on MgO-BaO-B2O3 Glasses

ISRN Ceramics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Samdani ◽  
Md. Shareefuddin ◽  
G. Ramadevudu ◽  
S. Laxmi Srinivasa Rao ◽  
M. Narasimha Chary
Keyword(s):  
Optical Absorption ◽  
Urbach Energy ◽  
Glass Composition ◽  
Glass Network ◽  
Spectroscopic Studies ◽  
Band Gaps ◽  
Compositional Dependence ◽  
Paramagnetic Resonance ◽  
Optical Band Gaps ◽  
Electron Paramagnetic

The mixed alkaline effect in double alkaline borate glasses MgO-BaO-B2O3 containing small proportions of copper oxide (CuO) has been studied. The glass samples are characterized by optical absorption, electron paramagnetic resonance (EPR), and Fourier transform infrared spectroscopy (FTIR). A red shift in optical absorption peaks with increasing MgO (decreasing BaO) concentration has been observed. The values of “g” tensor and hyperfine “A” tensor have shown inflections with glass composition. The number of spins (N) and paramagnetic susceptibility (χ) also exhibited mixed alkaline effect. The broadening of glass network with increase in MgO concentration is found from the FTIR spectra. Interestingly both density and molar volume have shown decreasing trend with glass composition. The optical band gaps exhibited a nonlinear compositional dependence. As expected, the glass samples possessed higher values of optical basicity (Λ), molar electronic polarizability (αm), and Urbach energy (ΔE).

scholarly journals Spectroscopic studies on the interaction of hypocrellin A with myoglobin

2007 ◽  
Vol 21 (4) ◽  
pp. 235-243 ◽  
Author(s):  
J. H. Zhou ◽  
X. H. Wu ◽  
C. Yang ◽  
X. T. Gu ◽  
L. Zhou ◽  
...  
Keyword(s):  
Binding Sites ◽  
Spectroscopic Analysis ◽  
Spectroscopic Studies ◽  
Interaction Process ◽  
Quenching Mechanism ◽  
Visible Absorption ◽  
Paramagnetic Resonance ◽  
Hypocrellin A ◽  
Uv Visible ◽  
Electron Paramagnetic

Experimental results of UV-visible absorption spectroscopy and fluorescence spectroscopy indicate that hypocrellin A, which has been studied in photodynamic therapy, can interact with the surface of myoglobin through hydrophobic forces, and form a complex. Based on the Stern–Volmer equation, the quenching constants of the process can be calculated to be 4.81×1012L mol−1s−1(t=25°C) and 4.54×1012L mol−1s−1(t=42°C) respectively, and the binding constant is 5.53×104M−1(t=25°C), while the binding sites is 0.94 (t=25°C). In addition, Electron paramagnetic resonance and fluorescence spectroscopic analysis suggests that that the quenching mechanism of the interaction process occurs through the electron transfer between hypocrellin A and myoglobin.

Structural and spectropscopic studies of a three-dimensional hydrogen-bonded copper(II) complex: aqua[bis(pyridin-2-ylcarbonyl)amidato]cyanidocopper(II)

2015 ◽  
Vol 71 (2) ◽  
pp. 165-168 ◽  
Author(s):  
Jiang-Yun Wang
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Epr Spectrum ◽  
Cyclic Voltammetric ◽  
Paramagnetic Resonance ◽  
Irreversible Oxidation ◽  
Square Planar ◽  
Voltammetric Studies ◽  
Cyclic Voltammetric Studies ◽  
Electron Paramagnetic

The preparation and X-ray and spectroscopic studies of the title copper(II) complex, [Cu(C12H8N3O2)(CN)(H2O)], are reported. The CuIIcation is five-coordinated, forming a distorted square-planar pyramid with an Addison τ parameter of 0.14. The UV–vis spectrum shows ad–dtransition of the CuIIcentre at 638 nm, and the electron paramagnetic resonance (EPR) spectrum confirms that the CuIIcation has an axial symmetry coordination and that the unpaired electrons occupy thedx2–y2orbital. Cyclic voltammetric studies show two irreversible oxidation and reduction peaks.

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