The Catalytic Function of Nonheme Iron (III) Complex for Hydrocarbon Oxidation

A detailed catalytic study of LFeIIICl (where L = 3-{2-[2-(3-hydroxy-1,3-diphenyl-allylideneamino)-ethylamino]-ethylimino}-1,3-diphenyl-propen-1-ol) for hydrocarbon oxidation was carried out, focusing on the role of solvent, atmospheric dioxygen, and oxidant on catalytic efficiency. The data showed that LFeIIICl catalyst was efficient in homogeneous hydrocarbon oxidations providing significant yields. Moreover, tert-BuOOH provided comparable oxidation yields with H2O2, slightly favoring the formation of alcohols and ketones versus epoxides. Dioxygen intervened in the catalytic reaction, influencing the nature of oxidation products. The polarity of solvent strongly influenced the reaction rates and the nature of oxidation products. A mechanistic model is postulated assuming that LFeIIICl functions via the formation of iron-hydroperoxo-species, followed by a radical-based mechanistic path

{N,N′-Bis[1-(2-pyrid­yl)ethyl­idene]propane-1,2-diamine-κ4 N,N′,N′′,N′′′}bis­(thio­cyanato-κN)manganese(II)

In the title compound, [Mn(NCS)2(C17H20N4)], the MnII atom is six-coordinated by the N,N′,N′′,N′′′-tetra­dentate Schiff base ligand and by two trans-N atoms from two thio­cyanate anions, forming a distorted octa­hedral geometry. The dihedral angle between the aromatic rings of the Schiff base is 9.5 (3)°

Envisioning Social Justice Education as Part of Inclusive Education

In this article, we approach the challenge of inclusive teacher education from the perspective of English language teaching (ELT). We do so by arguing for a broad(er) conception of inclusion that embraces diversity (rather than focusing on methodological challenges of learners with special educational needs) and which resonates with the Social Justice Education discourse. As one way of working towards social justice, we suggest uncovering and raising awareness of the representation of social inequities in cultural artifacts, using gender as our focal point. We present one activity that challenged student teachers to engage in inquiry-based learning concerning gender representations in their semiotic landscapes and show how this activity can serve as a puzzle piece in educating teachers for working towards social justice in their future English language classrooms. We emphasize the fact that the activity is embedded in pedagogical practices of modeling not only in the sense of teaching methodology, but in particular regarding the creation of democratic and compassionate classroom interaction that is needed for Social Justice Education and that we aim our students to introduce in their future classrooms, too. Finally, we draw some conclusions regarding ELT teacher education

Transition and Group IIB Metal Complexes With “Active Aldehyde” Derivatives of Thiamine

The Zn2+, Cd2+, Hg2+, Co2+ and Ni2+ ions produce zwitterionic type complexes with the ligands (L), 2-(α-hydroxy-benzyl)thiamine=HBT and 2-(α-hydroxy-cyclohexyl-methyl)thiamine = HCMT, of the type MLCl3. The ligands are in the S conformation, the metals are bound to N1, of the pyrimidine moiety of thiamine and the complexes have a trigonally distorted tetrahedral structure, as the crystal structure of the complex Zn(HCMT)Cl3 (orthorombic, a=14.4 b=14.1 c=17.4 β=105.6O V=3392A3 R=13.8%), the one and two dimensional 1H nmr spectra of the Zn2+, Cd2+ and Hg2+ complexes and the electronic spectra of the Co2+ and Ni2+ complexes show. A brief review of the previous techniques (structure of the Hg(HBT)Cl3 complex, IR-Raman spectra, 13C nmr in solution and solid state etc) used to characterize these complexes, is also given here and the proper conclusions drawn

{N,N′-Bis[1-(2-pyrid­yl)ethyl­idene]ethane-1,2-diamine-κ4 N,N′,N′′,N′′′}(thio­cyanato-κN)zinc(II) perchlorate

In the title compound, [Zn(NCS)(C16H18N4)]ClO4, the ZnII atom is five-coordinated by four N atoms of the Schiff base ligand N,N′-bis­[1-(2-pyrid­yl)ethyl­idene]ethane-1,2-diamine in the basal plane, and by the N atom of a thio­cyanate ligand at the apical position, forming a distorted square-pyramidal geometry. The r.m.s. deviation from a plane through the four N atoms of the Schiff base is 0.015 (3) Å, and the deviation of the Ni atom from that plane is 0.591 (2) Å. Bond lengths are comparable with those observed in similar zinc(II) complexes with Schiff bases. The two methyl­ene C atoms of the ethane-1,2-diamine bridge of the Schiff base ligand are disordered over two sites with occupancies of 0.587 (3) and 0.413 (3)

A combined experimental and theoretical investigation of oxidation catalysis by cis-[VIV(O)(Cl/F)(N4)]+ species mimicking the active center of metal-enzymes

Reaction of VIVOCl2 with the nonplanar tetradentate N4 bis-quinoline ligands yielded four oxidovanadium(IV) compounds of the general formula cis-[VIV(O)(Cl)(N4)]Cl. Sequential treatment of the two nonmethylated N4 oxidovanadium(IV) compounds with KF and NaClO4 resulted in the isolation of the species with the general formula cis-[VIV(O)(F)(N4)]ClO4. In marked contrast, the methylated N4 oxidovanadium(IV) derivatives are inert toward KF reaction due to steric hindrance, as evidenced by EPR and theoretical calculations. The oxidovanadium(IV) compounds were characterized by single-crystal X-ray structure analysis, cw EPR spectroscopy, and magnetic susceptibility. The crystallographic characterization showed that the vanadium compounds have a highly distorted octahedral coordination environment and the d(VIV–F) = 1.834(1) Å is the shortest to be reported for (oxido)(fluorido)vanadium(IV) compounds. The experimental EPR parameters of the VIVO2+ species deviate from the ones calculated by the empirical additivity relationship and can be attributed to the axial donor atom trans to the oxido group and the distorted VIV coordination environment. The vanadium compounds act as catalysts toward alkane oxidation by aqueous H2O2 with moderate ΤΟΝ up to 293 and product yields of up to 29% (based on alkane); the vanadium(IV) is oxidized to vanadium(V), and the ligands remain bound to the vanadium atom during the catalysis, as determined by 51V and 1H NMR spectroscopies. The cw X-band EPR studies proved that the mechanism of the catalytic reaction is through hydroxyl radicals. The chloride substitution reaction in the cis-[VIV(O)(Cl)(N4)]+ species by fluoride and the mechanism of the alkane oxidation were studied by DFT calculations

Analysis of turbulence and surface growth models on the estimation of soot level in ethylene non-premixed flames

Soot prediction in a combustion system has become a subject of attention, as many factors influence its accuracy. An accurate temperature prediction will likely yield better soot predictions, since the inception, growth and destruction of the soot are affected by the temperature. This paper reported the study on the influences of turbulence closure and surface growth models on the prediction of soot levels in turbulent flames. The results demonstrated that a substantial distinction was observed in terms of temperature predictions derived using the k-ε and the Reynolds stress models, for the two ethylene flames studied here amongst the four types of surface growth rate model investigated, the assumption of the soot surface growth rate proportional to the particle number density, but independent on the surface area of soot particles, ƒ(As) = ρNs , yields in closest agreement with the radial data. Without any adjustment to the constants in the surface growth term, other approaches where the surface growth directly proportional to the surface area and square root of surface area, ƒ(As) = As and ƒ(As) = √As, result in an under- prediction of soot volume fraction. These results suggest that predictions of soot volume fraction are sensitive to the modelling of surface growth

Transported probability density function : modelling of turbulent jet flames

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