Prática de ensino supervisionada em ensino de Educação Musical no Ensino Básico

Este é o relato de experiências de ensino-aprendizagem realizadas no âmbito da Prática de Ensino Supervisionada, do Mestrado em Ensino da Educação Musical no Ensino Básico, ministrado na Escola Superior de Educação do Instituto Politécnico de Bragança. Estas experiências foram realizadas ao longo dos 1º, 2º e 3º ciclos do Ensino Básico, tendo como principal motivação a valorização da produção musical, nos domínios da composição e da interpretação, enquanto estratégia de acção capaz de contribuir para novas possibilidades de intervenção pedagógica ao nível da Educação Musical. Nos 1º e 2º ciclos, foram realizados projectos pedagógicos que cruzaram várias disciplinas artísticas e, no 3º ciclo, foi feita uma abordagem pedagógica orientada para o ensino instrumental, de forma a estreitar os espíritos do ensino “genérico” e do ensino vocacional da música. Destas experiências e abordagens pedagógicas decorreu uma reflexão crítica que pode conter elementos a ter em conta para uma discussão acerca das orientações do sistema de ensino da música em Portugal.This is the report of teaching and learning experiences occurred during the Supervised Teaching Practice, of the Master in Teaching Music Education in Primary Education, taught in the School of Education, Polytechnic Institute of Bragança. These experiences were carried out over the 1st, 2nd and 3rd cycles of basic education and to do so music production, in the fields of composition and interpretation, was the main motivation while strategy that can contribute to new possibilities of pedagogical intervention at the Musical Education level. In the 1st and 2nd cycles were conducted educational projects that intersected multiple artistic disciplines and, in the 3rd cycle, there was a pedagogical approach oriented for the instrumental teaching, in order to strengthen the spirit of the "generic" and the vocational systems of music education. These experiences and pedagogical approaches were subject of a critical reflection that can contain elements to consider for a discussion about the music education system on Portugal

Teaching the Cummins Complex Heterodimerization: Formation of Unorthodox Heteroleptic X3MoMoY3 Dimers with Ultralong Metal-Metal Triple Bonds

Attempts to stabilize mononuclear trigonal-planar Mo(+3) complexes by (tripodal) silanolates or alkoxides, which had recently been shown to synergize exceedingly well with high valent molybdenum or tungsten alkylidynes, afforded unsymmetrical dimolybdenum complexes of the general type [X3MoMoY3]; not only is this ligand pattern unprece-dented, but these dimers incorporate the intact Cummins complex [(tBu)(Ar)N]3Mo (Ar = 3,5-dimethylphenyl), which is famous for not engaging in metal-metal triple bonding otherwise. The remarkable ease of heterodimerization likely reflects a pronounced kinetic selectivity. The new complexes were characterized by crystallographic and spectroscopic means; they show highly deshielded 95Mo NMR signals and comprise unusually long yet robust MoMo bond

Canopy Catalysts for Alkyne Metathesis: Investigations into a Bimolecular Decomposition Pathway and the Stability of the Podand Cap

Molybdenum alkylidyne complexes with a trisilanolate podand ligand framework (“canopy catalysts”) are the arguably most selective catalysts for alkyne metathesis known to date. Among them, complex 1 a endowed with a fence of lateral methyl substituents on the silicon linkers is the most reactive, although fairly high loadings are required in certain applications. It is now shown that this catalyst decomposes readily via a bimolecular pathway that engages the Mo≡CR entities in a stoichiometric triple-bond metathesis event to furnish RC≡CR and the corresponding dinuclear complex, 8, with a Mo≡Mo core. In addition to the regular analytical techniques, $^{95}$Mo NMR was used to confirm this unusual outcome. This rapid degradation mechanism is largely avoided by increasing the size of the peripheral substituents on silicon, without unduly compromising the activity of the resulting complexes. When chemically challenged, however, canopy catalysts can open the apparently somewhat strained tripodal ligand cages; this reorganization leads to the formation of cyclo-tetrameric arrays composed of four metal alkylidyne units linked together via one silanol arm of the ligand backbone. The analogous tungsten alkylidyne complex 6, endowed with a tripodal tris-alkoxide (rather than siloxide) ligand framework, is even more susceptible to such a controlled and reversible cyclo-oligomerization. The structures of the resulting giant macrocyclic ensembles were established by single-crystal X-ray diffraction

Synthesis, Reactivity and Antimicrobial Activity of a Series of 2-Arylamino-1,3-selenazoles

A series of 2-arylamino-1,3-selenazoles was synthesized and their reactivity was studied. The 2-arylamino-1,3-selenazoles and their reaction products were characterized by various spectroscopic methods and X-ray diffraction. In addition, the antimicrobial activity of the 2-arylamino-1,3-selenazoles in a panel of seven bacteria and fungi was examined

An Anionic Dinuclear Ruthenium Dihydrogen Complex of Relevance for Alkyne gem-Hydrogenation

During an investigation into the fate of ruthenium precatalysts used for light-driven alkyne gem-hydrogenation reactions with formation of Grubbs-type ruthenium catalysts, it was found that the reaction of [(IPr)(eta(6)-cymene)RuCl2] with H-2 under UV-irradiation affords an anionic dinuclear sigma-dihydrogen complex, which is thermally surprisingly robust. Not only are anionic sigma-complexes in general exceedingly rare, but the newly formed species seems to be the first example lacking any structural attributes able to counterbalance the negative charge and, in so doing, prevent oxidative insertion of the metal centers into the ligated H-2 from occurring.ISSN:1433-7851ISSN:1521-3773ISSN:0570-083

Synthesis, Isolation and Characterization of Two Cationic Organo-bismuth(II) Pincer Complexes Relevant in Radical Redox Chemistry

Herein, we report the synthesis, isolation and characterization of two cationic organobismuth(II) compounds bearing N,C,N pincer frameworks, which are crucial intermediates in bismuth radical processes. X-ray crystallography uncovered a monomeric Bi(II) structure, while SQUID magnetometry in combination with NMR and EPR spectroscopy provide evidence for a para-magnetic S = 1/2 state. High resolution multifrequency EPR at X, Q, and W-band enable the precise assignment of the full g- and 209Bi A-tensors. Experimental data and DFT calculations reveal both complexes are metal-centered radicals with little delocalization onto the ligands

"Canopy Catalysts" for Alkyne Metathesis: Molybdenum Alkylidyne Complexes with a Tripodal Ligand Framework

A new family of structurally well-defined molybdenum alkylidyne catalysts for alkyne metathesis, which is distinguished by a tripodal trisilanolate ligand architecture, is presented. Complexes of type 1 combine the virtues of previous generations of silanolate-based catalysts with a significantly improved functional group tolerance. They are easy to prepare on scale; the modularity of the ligand synthesis allows the steric and electronic properties to be fine-tuned and hence the application profile of the catalysts to be optimized. This opportunity is manifested in the development of catalyst 1f, which is as reactive as the best ancestors but exhibits an unrivaled scope. The new catalysts work well in the presence of unprotected alcohols and various other protic groups. The chelate effect entails even a certain stability toward water, which marks a big leap forward in metal alkylidyne chemistry in general. At the same time, they tolerate many donor sites, including basic nitrogen and numerous heterocycles. This aspect is substantiated by applications to polyfunctional (natural) products. A combined spectroscopic, crystallographic, and computational study provides insights into structure and electronic character of complexes of type 1. Particularly informative are a density functional theory (DFT)-based chemical shift tensor analysis of the alkylidyne carbon atom and 95Mo NMR spectroscopy; this analytical tool had been rarely used in organometallic chemistry before but turns out to be a sensitive probe that deserves more attention. The data show that the podand ligands render a Mo-alkylidyne a priori more electrophilic than analogous monodentate triarylsilanols; proper ligand tuning, however, allows the Lewis acidity as well as the steric demand about the central atom to be adjusted to the point that excellent performance of the catalyst is ensured.ISSN:0002-7863ISSN:1520-512

Radical Activation of Ammonia and Water at Bismuth(II)

The development of unconventional strategies for the activation of ammonia (NH3) and water (H2O) is of capital importance for the advancement of sustainable chemical strategies. Herein we provide the synthesis and characterization of a Radical Equilibrium Com-plex based on bismuth featuring an extremely weak Bi‒O bond, that permits the in situ generation of reactive Bi(II) species. The en-suing organobismuth(II) engages with various ammines and alcohols and exerts an unprecedented effect onto the X‒H, leading to low BDFEX-H. As a result, radical activation of various N‒H and O‒H bonds—including ammonia and water—occurs in seconds at room temperature, delivering well-defined Bi(III)-amido and -alkoxy complexes. Moreover, we demonstrate that the resulting Bi(III)‒N complexes engage in a unique reactivity pattern with the triad of H+, H‒ and H· sources, thus providing alternative pathways for main group chemistry

Strain-release Pentafluorosulfanylation and Tetrafluoro(aryl)sulfanylation of [1.1.1]Propellane: Reactivity and Structural Insight

We leveraged the recent increase in synthetic accessibility of SF5Cl and Ar-SF4Cl compounds to combine chemistry of the SF5 and SF4Ar groups with strain-release functionalization. By effectively adding SF5 and SF4Ar radicals across [1.1.1]propellane, we accessed structurally unique bicyclopentanes, bearing two distinct elements of bioisosterism. Upon evaluating these “hybrid isostere” motifs in the solid state, we measured exceptionally short transannular distances; in one case, the distance rivals the shortest nonbonding C···C contact reported to date. This prompted SC-XRD and DFT analyses that support the notion that a donor-acceptor interaction involving the “wing” C–C bonds is playing an important role in stabilization. Thus, these heretofore unknown structures expand the palette for highly coveted three-dimensional fluorinated building blocks and provide insight to a more general effect observed in bicyclopentanes

A “non-magnetic” triplet bismuthinidene enabled by relativity

Isolation and stabilization of main group diradical species have posed a synthetic challenge over the years due to their intrinsic high reactivity. Herein we report on a large-scale synthesis and isolation of a mono-coordinate bismuthinidene featuring a rigid and bulky ligand, which protects the Bi(I) center. The compound was characterized by its unique spectroscopic features (UV-vis and NMR), but more prominently, by its magnetic properties. Multiconfigurational quantum chemical calculations predict the ground state of the compound to be dominated by a spin-triplet. Further support for this electronic structure description was obtained through correlation of theory to experimental XRD, XAS, and UV-Vis data. However, all magnetic measurements (EPR, NMR and SQUID) point to a diamagnetic compound. This apparent discrepancy can be explained by an extremely large spin-orbit coupling (SOC) that leads to an unprecedented zero-field splitting of more than 8000 cm‒1, thus leaving a MS = 0 magnetic sublevel thermally isolated in the electronic ground state. The extremely large SOC effect is a result of the low-coordination number of the bismuth center in interplay with its heavy element nature