Photolabile (µ-peroxo)(µ-hydroxo)bis[bis(bipyridyl)-cobalt-based caged oxygen compounds have been synthesized and characterized by optical absorbance spectroscopy, X-ray crystallography. and the quantum yield and redox stability were investigated. Furthermore, conditions were established where redox incompatibilities encountered between caged oxygen compounds and oxygen-dependant cytochrome c oxidase (CcO) could be circumvented.
View Article and Find Full Text PDFA selective [4 + 2] cycloaddition reaction of thiazolo-2-pyridones with arynes has been demonstrated. The developed protocol allows rapid access to highly functionalized, structurally complex thiazolo-fused bridged isoquinolones in high yields, which are susceptible to further late-stage functionalization.
View Article and Find Full Text PDFA number of transition metal hydrides reveal intriguing temperature-dependent in their deuterated derivatives and possibly the temperature dependent hydrogen-hydrogen distance ((H-H)) as well. Previously, theoretical studies rationalized and (H-H) changes in such compounds through a "temperature-elastic" structure model with a significant population of vibrational states in an anharmonic potential. Based on the first variable temperature neutron diffraction study of a relevant complex, (-H-POCOP)IrH, observation of its elusive counterpart with longer (H-H), crystallized as an adduct with CFI, and thorough spectroscopic and computational study, we argue that the model involving isomeric species in solution at least in some cases is more relevant.
View Article and Find Full Text PDFPurpose: People who stutter (PWS) are vulnerable to the development of various psychopathological symptoms, although prevalence data are mixed and less clarity exists about factors that potentially influence their occurrence. The current study sought to shed light on the prevalence of self-reported psychopathology in PWS and aimed to identify relationships between affective, behavioral, and cognitive (ABC) experiences of stuttering and psychological distress (PD).
Method: Forty-four PWS were administered the Behavior Assessment Battery (BAB) for Adults who Stutter and the Brief Symptom Inventory-18.
Four new pentadentate N5-donor ligands, [-(1-methyl-2-imidazolyl)methyl--(2-pyridyl)-methyl--(bis-2-pyridylmethyl)-amine] (), [-bis(1-methyl-2-imidazolyl)methyl--(bis-2-pyridylmethyl)amine] (), (-(isoquinolin-3-ylmethyl)-1,1-di(pyridin-2-yl)--(pyridin-2-ylmethyl)methanamine (), and ,-bis(isoquinolin-3-ylmethyl)-1,1-di(pyridin-2-yl)methanamine (), have been synthesized based on the N4Py ligand framework, where one or two pyridyl arms of the N4Py parent are replaced by (-methyl)imidazolyl or -(isoquinolin-3-ylmethyl) moieties. Using these four pentadentate ligands, the mononuclear complexes [Fe(CHCN)()] (), [Fe(CHCN)()] (), [Fe(CHCN)()] (), and [Fe(CHCN)()] () have been synthesized and characterized. The half-wave potentials () of the complexes become more positive in the order: < < ≤ ≤ [Fe(N4Py)(CHCN)].
View Article and Find Full Text PDFPurpose: Miniature linguistic systems (also known as matrix training) is a method of organizing learning targets to achieve generative learning or recombinative generalization. This systematic review is aimed at determining whether matrix training is effective for individuals with autism spectrum disorder (ASD) in terms of improving recombinative generalization for instruction-following, expressive language, play skills, and literacy skills.
Method: A systematic review methodology was employed to limit bias in the various review stages.
Herein we report an efficient hydrosilylation strategy to selectively defunctionalize biomass-derived levulinic acid into value-added chemicals such as pentane-1,4-diol, pentan-2-ol, 2-MTHF and C hydrocarbons by using cost-effective silanes and the commercially available catalyst B(C F ) at room temperature. All reactions work well in chlorinated solvents but, as a greener alternative, most reactions can be run in toluene or solvent-less.
View Article and Find Full Text PDFCoal combustion greatly contributes to global emissions of toxic gases into the atmosphere, with sulfur emissions as one of the prominent pollutants in addition to carbon dioxide. Nevertheless, Botswana utilizes Morupule's sub-bituminous coal with average sulfur and ash contents, as determined in this study being 1.9 and 24.
View Article and Find Full Text PDFTo enable the large-scale use of hydrogen fuel cells for mobility applications, convenient methods for on-board hydrogen storage and release are required. A promising approach is liquid organic hydrogen carriers (LOHCs), since these are safe, available on a large scale, and compatible with existing refueling infrastructure. Usually, LOHC dehydrogenation is carried out in batch-type reactors by transition metals and their complexes and suffers from slow H release kinetics and/or inability to reach high energy density by weight, owing to low conversion or the need to dilute the reaction mixture.
View Article and Find Full Text PDFFrom the reaction of 2-hydroxy-6-methylpyridine (L) with iron(II) tetrafluoroborate, a new mononuclear iron(III) octahedral complex [FeL](BF) has been isolated. The color of the complex reversibly changed from red at room temperature to yellow-orange at the liquid nitrogen temperature. Magnetization measurements indicate that iron(III) in [FeL](BF) is in a high-spin state = 5/2, from room temperature to 1.
View Article and Find Full Text PDFA series of iron(II) complexes with the general formula [Fe()(L)] ( = 1, L = F, Cl; = 2, L = NCMe, HO) have been isolated and characterized. The X-ray crystallographic data reveals that metal-ligand bond distances vary with varying ligand field strengths of the sixth ligand. While the complexes with fluoride, chloride and water as axial ligand are high spin, the acetonitrile-coordinated complex is in a mixed spin state.
View Article and Find Full Text PDFSmart watches are discreet and wearable tools that may be repurposed to improve directive-following for individuals with autism spectrum disorder (ASD). Specifically, a mentor can transmit just-in-time (JIT) visual supports (e.g.
View Article and Find Full Text PDFNaturally occurring phyllosilicate minerals such as talc and vermiculite in conjunction with n-tetra butyl ammonium bromide (TBAB) co-catalyst were found to be efficient in the coupling of CO with epoxides to form cyclic carbonates. The reaction was carried out in a pressurized autoclave reactor at moderate pressures of 10-35 bars and temperatures of 100-150 °C. The optimized catalyst system exhibited > 90% conversion of the epoxides and > 90% selectivity for the desired cyclic carbonates, in the presence or absence of a solvent.
View Article and Find Full Text PDFThis study used a multiple baseline, single-subject research design to investigate the efficacy of an iPad-based speech-generating device (SGD). The iPad was equipped with the SPEAKall! application to function as a SGD. SGDs are a form of aided augmentative and alternative communication (AAC) allowing a user to communicate using digitized and/or synthesized speech.
View Article and Find Full Text PDFA new generation of N-heterocyclic carbene palladium(II) complexes containing vinyl groups in different positions in the backbone of the N-heterocycle have been developed. The fully characterised monomers were copolymerised with divinylbenzene to fabricate robust polymer supported NHC-Pd complexes and these polymers were applied as heterogeneous catalysts in directed C-H halogenation of arenes with a pyridine-type directing group. The catalysts demonstrated medium-high catalytic activity with up to 90 % conversion and 100 % selectivity in chlorination.
View Article and Find Full Text PDFWe report the first examples of the carbide ligand in (CyP)ClRu≡C (RuC) developing into a μ ligand toward metal centers. Conventionally, sterics exclude this coordination mode, but Fe(CO) and Co(CO) expel bridging CO ligands upon reaction with RuC to form trimetallic (CyP)ClRu═CFe(CO) (RuCFe) and (CyP)ClRu═CCo(CO) (RuCCo) complexes. Thus, the proximity offered by metal-metal associations in bimetallic carbonyl complexes allows the formation of trinuclear carbide complexes as verified by NMR, Mössbauer, and X-ray spectroscopic techniques.
View Article and Find Full Text PDFA simple method has been developed for the cross dehydrogenative coupling between two different primary alcohols using readily available RuCl(PPh) as a precatalyst through the borrowing-hydrogen approach. The present methodology is applicable to a large variety of alcohol derivatives including long chain aliphatic alcohols and heteroaryl alcohols. In addition, the methodology was applied in a straightforward protocol to synthesize commercially available fragrances such as Rosaphen and Cyclamenaldehyde in good yields.
View Article and Find Full Text PDFEvidence-based practice as a process requires the appraisal of research as a critical step. In the field of developmental disabilities, single-case experimental designs (SCEDs) figure prominently as a means for evaluating the effectiveness of non-reversible instructional interventions. Comparative SCEDs contrast two or more instructional interventions to document their relative effectiveness and efficiency.
View Article and Find Full Text PDFA series of complexes with oxathiacrown ethers appended to a [Ru(bpy)] moiety have been synthesized and characterised using H NMR, C NMR, IR, electronic absorption and emission spectroscopies, mass spectrometry and elemental analyses. The complexes exhibit strong MLCT luminescence bands in the range 608-611 nm and one reversible metal centred oxidation potential in the range 1.00-1.
View Article and Find Full Text PDFJ Phys Condens Matter
November 2017
We have studied the reaction of phenylacetylene (PA) with chloro-, bromo-, and iodobenzene on the Au(1 1 1) surface as a model system for the gold-catalysed Sonogashira cross-coupling. Both ultrahigh vacuum-based and ambient pressure x-ray photoelectron spectroscopy show that iodo- and chlorobenzene (IB and CB) undergo the cross-coupling reaction towards diphenylacetylene. Bromobenzene (BB), in contrast, does not react in the UHV experiments.
View Article and Find Full Text PDFHeterogeneous catalysts for selective oxidation of C-H bonds were synthesized by co-polymerization of new N-heterocyclic carbene-palladium(II) (NHC-Pd ) monomers with divinylbenzene. The polymer-supported NHC-Pd -catalysed undirected C-H acetoxylation of simple and methylated arenes as well as polyarenes, with similar or superior efficiency compared to their homogeneous analogues. In particular, the regioselectivity has been improved in the acetoxylation of biphenyl and naphthalene compared to the best homogeneous catalysts.
View Article and Find Full Text PDFCyclometallation of 8-methylquinoline and 2-(dimethylamino)-pyridine in an iridium-based pincer complex is described. The C-H activation of 2-(dimethylamino)pyridine is not chelation assisted, which has not been described before for Csp -H bonds in cyclometallation reactions. The mechanism of the cyclometallation of 2-(dimethylamino)pyridine was studied by DFT calculations and kinetic measurements.
View Article and Find Full Text PDFA novel electron deficient 4,6-bis(trifluoromethyl)-1,3-phenylene diphosphinite ligand 4 was developed and synthesized. Reaction of Ir precursors with ligand 4 gave chloro(hydride) pincer complex 5, which demonstrated a higher TON in alkane dehydrogenation reactions compared to similar phosphinite based pre-catalysts. The formation of cyclooctene (COE) and tert-butylethylene adducts of the 14e catalysts was also studied and the COE adduct is implicated as the resting state of the catalyst.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
April 2016
The title compound, [PdCl2(C11H9N)(C13H14N2)], represents a new class of palladium-based polymerizable monomer which could give a potentially catalytically active polymer. It was synthesized via transmetallation from the corresponding silver complex. The Pd(II) ion coordinates two Cl anions, one C atom from the N-heterocyclic carbene (NHC) ligand and one N atom from the 4-phenyl-pyridine ligand, displaying a slightly distorted square-planar geometry.
View Article and Find Full Text PDFThe hydride iridium pincer complex [(PCyP)IrH2] (PCyP=cis-1,3-bis[(di-tert-butylphosphino)methyl]cyclohexane, 1) reveals remarkably solvent-dependent hydride chemical shifts, isotope chemical shifts, JHD and T1(min), with rHH increasing upon moving to more polar medium. The only known example of such behaviour (complex [(POCOP)IrH2], POCOP=2,6-(tBu2PO)2C6H3) was explained by the coordination of a polar solvent molecule to the iridium (J. Am.
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