A comparative study of surface oxidation behaviour of amorphous and crystallized Ni36Fe32Cr14P12B6 metallic glass using Auger Electron Spectroscopy

Native oxide and in situ oxidation of amorphous Ni₃₆Fe₃₂Cr₁₄P₁₂B₆ have been investigated at room temperature using Auger Electron Spectroscopy. The Ni₃₆Fe₃₂Cr₁₄P₁₂B₆ sample has been annealed as ～ 800 K in UHV and its oxidation behaviour has been studied at room temperature. A comparison of in situ oxidized amorphous and crystallized samples has been carried out.     

New Mn(II), Co(II), Ni(II) and Cu(II) homoleptic complexes with 6-chloro-5-7-dimethyl-4oxo-4H-chromene-3-carbaldehydes and its heteroleptic complexes with quinoline-8 ol: synthesis,characterization and antimicrobial activity

Research on Chemical Intermediates - In the present study, the synthesis of ligand 6-chloro-5-7-dimethyl-4oxo-4H-chromene-3-carbaldehydes by three steps from the substituted phenol. The formed...     

A coupled analytical–FE hybrid approach for elastostatics

Meccanica - Beginning with augmentation of experimental boundary-data with numerical methods in early hybrid methods (HMs), HMs have evolved in various states of hybridization amalgamating...     

Energetics of model compounds of water oxidizing complex containing quinone cofactors

To reveal reaction mechanism of PS-II, the reaction products of photolysis may be compared with their thermolytic products. According to required molecular assemblies in manganese clusters at WOC of PS-II, we have strategically synthesized dimers (M-1, M-2), trimers (M-3A, M-3B) and tetramer (M-4) using spin carrier imino-phenol functionalized ligands viz. Lawsone Oxime (L-1) and Phthiocol Oxime (L-2) of naturally occurring quinones .These are characterized by elemental analyses, thermogravimetric analyses, differential thermal analyses, powder X-ray diffraction and infrared spectroscopy. Stabilization energies for molecular associations of ligands in various redox and stereoisomeric forms via hydrogen bondings are compared with thermal energies required for their expulsion from the coordination polymers calculated with the help of Coats and Redfern’s relation of rising temperatures. Activation energy required for establishing tetramer (M-4) and dimer (M-2) in coordination sphere by counter ion using same synthetic route is found to be comparable (~37.48±1 kJ mol^-1). Quantitized energies from TG-DTA data for valence tautomers of redox active ligands play significant role in formation of resultant model compound. viz. tetramer, dimer of dimer and trimer. The role of oxo, acetato and spin carrier ligands in model cluster compounds are proposed with respect to their expulsion energies.     

Ab initio and density functional studies on the structure and vibrational spectra of 2-hydroxy-1,4-naphthoquinone-1-oxime derivatives

Structure and vibrational frequencies of lawsoneoxime and its C₃-substituted (R=CH₃, NH₂, Cl, NO₂) derivatives in keto and nitrosophenol forms have been obtained employing the Hartree–Fock and density functional methods. Charge distributions in different conformers have been studied using the molecular electrostatic potential topography as a tool. For all these derivatives except for nitrolawsoneoxime the amphi conformer in the keto form is predicted to be of lowest energy, which can partly be attributed to hydrogen bonding through the oximino nitrogen. In the nitro derivative, however, the preference to form a six membered ring owing to O–H–O hydrogen-bonded interactions makes the anti conformer (keto) the stablest. Further one of the nitrosophenol conformers of nitrolawsoneoxime turns out to be very close in energy (0.21 kJ mol^–1 higher) to this anti conformer. The consequences of hydrogen bonding on charge distribution and vibrational spectra are discussed.