Coordination Modes of Aminodiphosphane Ligands to the Cuboidal Mo3S4 Cluster Unit

[EN] Molecular molybdenum cluster sulphides are an unexpensive alternative to noble metal based homogenous catalysts. In this paper, we present the synthesis of the first PNP Mo3S4 derivative as well as the crystal structure of the isomer which contains the ligand bound in a bidentate fashion. The potential of this new complex as precursor for heterobimetallic systems is also analyzed.Our results indicated that Mo3S4 cluster cores can be functionalized with aminodiphosphine groups acting as bidentate or tridentate ligands.The financial support of the Spanish Ministerio de Economía y Competitividad (Grant CTQ2015-65207), Universitat Jaume I (Research Project P1·1B2013-19) and Generalitat Valenciana (Prometeo/2014/022) is gratefully acknowledged. The authors also thank the Servei Central d Instrumentació Científica (SCIC) of the University Jaume I for providing us with the mass spectrometry, NMR, elemental analysis and X-ray facilities. C.A. thanks the Spanish Ministerio de Economía y Competitividad for a predoctoral fellowship (FPI).Alfonso, C.; Feliz Rodriguez, M.; Llusar, R. (2017). Coordination Modes of Aminodiphosphane Ligands to the Cuboidal Mo3S4 Cluster Unit. Current Inorganic Chemistry. 7(2):106-110. https://doi.org/10.2174/1877944107666171025162409S1061107

Pérmico continental en España

[ES] Los conocimientos que hasta el momento se poseen, indican que en España el Pérmico está representado por el «Autuniense» (Rotliegendes Inferior) en facies grises características y por formaciones rojas que son atribuidas al «Saxoniense» (Rotliegendes Superior). El Pérmico Superior sólo ha sido citado en muy escasos puntos. En general, está constituido por series detríticas, cuyo tamaño va desde la arcilla, hasta conglomerados de gruesos bloques. Frecuentemente se intercalan rocas volcánicas de diversos tipos. Su potencia es muy variable, pudiendo llegar a alcanzar espesores de más de 2.000 m. Su deposición se realiza en cuencas continentales condicionadas normalmente por la tectónica tardihercinica. Todas sus características, así como los problemas que plantea su cronoestratigrafia son muy similares a los del Pérmico de Europa Occidental.[FR] Les connaissances aujourd’hui acquisses indiquent quen Espagne, le Permien est répresente par «l’Autunien» (Rotliegendes Infericur) en facies gris characteritiques et par des formations rouges atribuées au «Saxonien» (Rotliegendes Superieur). Le Permien Supericur a été identifle seulement dans quelques points. En general, les séries sont constituées par des seditnents détritiques, des les argiles juqua les conglomerats; frequentment on trouve des passées volcaniques de type divers. Sa puissance est tres variable, jusqua 2.000 metres maximum; sa deposition prend lieu dans bassins continentaux controlés normalement par la tectonique tardihercynienne. Ses characteritiques et ses problemes sont tres similaires a ceux du Permien de lEurope Occidentale.[EN] The present data show that the Spanish Permian is represented by the «Autunian» (Lower Rotliegendes) in a typical grey facies and redbeds similar to the «Saxonian» (Upper Rotliegendes). The Upper Permian has been found only in a very few points. In general it is made of detrital series, from clays to conglomerates; some volcaníc levels are found. Tickness is very variable, up to 2.000 meters. Sedimentation takes place in continental basins, tectonically con troled 1w the tardihercynian pbases. Their caracteristics and problenis are similar to the ones of Western European Permian.Peer reviewe

C3-symmetry Mo3S4 aminophosphino clusters combining three sources of stereogenicity: stereocontrol directed by hydrogen bond interactions and ligand configuration

A diastereoselective synthesis of proline containing aminophosphino cubane-type Mo3S4 clusters, (P)-[Mo3S4Cl3((1S,2R)-PPro)3]Cl ((P)-[Mo-(SN,RC)]Cl) and (P)-[Mo3S4Cl3((1S,2S)-PPro)3]Cl ((P)-[Mo-(SN,SC)] Cl), has been achieved in high yields by reacting the corresponding enantiomerically pure PPro ((R)- and (S)-2-[(diphenylphosphino)methyl]pyrrolidine) ligands with the Mo3S4Cl4(PPh3)3(H2O)2 complex. Circular dichroism, nuclear magnetic resonance and X-ray techniques confirm that the (P)-[Mo-(SN,RC)]Cl and (P)-[Mo-(SN,SC)]Cl cluster cations are diastereoisomers which combine three sources of stereogenicity provided by the cluster framework, one carbon atom of the aminophosphine ligand and the nitrogen stereogenic center. The higher stability of the (P)-[Mo-(SN,SC)]+ cation is due to stabilizing vicinal Cl⋯HN interactions as well as due to the cis-fused conformation of the bicyclic system formed upon coordination of the aminophosphine ligand.The financial support of the Spanish Ministerio de Economía y Competitividad (Grant CTQ2011-23157 and CTQ2015-65207-P), Universitat Jaume I (Research Project P1·1B2013-19) and Generalitat Valenciana (PROMETEOII/2014/022) is gratefully acknowledged. The authors also thank the Servei Central d’Instrumentació Científica (SCIC) of the University Jaume I for providing us with the mass spectrometry, NMR and X-ray facilities. C. A. thanks the Spanish Ministerio de Economía y Competitividad for a predoctoral fellowship (FPI)

Influence of the Diphosphine Coordinated to Molybdenum and Tungsten Triangular M3S4 Cluster Hydrides in the Catalytic Hydrodefluorination of Pentafluoropyridine

Hydrido molybdenum and tungsten(IV) cluster cations of formula [M3S4H3(dppe)3]+ (dppe = 1,2-(bis)dimethylphosphinoethane), [Mo-1]+ (M = Mo) and [W-1]+ (M = W), have been isolated by reacting their halide precursors with borohydride. Synthetic procedures have been optimized by appropriate choice of the solvent. Furthermore, [M3S4F3(dppe)3]+ fluorido cluster complexes, [Mo-2]+ (M = Mo) and [W-2]+ (M = W) have been prepared through halogen substitution reactions using an excess of cesium fluoride. The structures of [Mo-1]+ and [Mo-2]+ have been determined by single crystal X-ray diffraction experiments. These [M-1]+ hydrido and [M-2]+ fluorido clusters have been used as catalysts and precatalysts, respectively, in the catalytic hydrodefluorination (HDF) of pentafluoropyridine using HSiMe2Ph as hydrogen source. The reaction proceeds under microwave and reflux conditions to selectively afford 2,3,5,6-tetrafluoropyridine. The [W-1]+ hydrido cluster is the most efficient catalyst with turnover numbers of 124, while the [Mo-1]+ hydrido cluster reacts faster. Fluorido [Mo-2]+ and [W-2]+ complexes provide lower yields and turnover numbers. In general, the molybdenum and tungsten [M-1]+ and [M-2]+ diphosphino complexes are more efficient than their dmpe (1,2-(bis)dimethylphosphinoethano) analogues and activate pentafluoropyridine under softer conditionsThe financial support of the Spanish Ministerio de Economía y Competitividad (Grant CTQ2011-23157), Universitat Jaume I (Research Project P1·1B2013-19) and Generalitat Valenciana (ACOMP/2013/215 and Prometeo/2009/053) is gratefully acknowledged. The authors also thank the Servei Central d’Instrumentació Científica (SCIC) of the University Jaume I for providing us with the mass spectrometry, NMR and X-ray facilities. C.A. thanks the Spanish Ministerio de Economía y Competitividad for a predoctoral fellowship (FPI)

El Pérmico y el Triásico del borde sur-este del Sistema Central: día IV

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Overexpression of BvHb2, a Class 2 Non-Symbiotic Hemoglobin from Sugar Beet, Confers Drought-Induced Withering Resistance and Alters Iron Content in Tomato

Drought stress is one of the major threats to agriculture and concomitantly to food production. Tomato is one of the most important industrial crops, but its tolerance to water scarcity is very low. Traditional plant breeding has a limited margin to minimize this water requirement. In order to design novel biotechnological approaches to cope with this problem, we have screened a plant cDNA library from the halotolerant crop sugar beet (Beta vulgaris L.) for genes able to confer drought/osmotic stress tolerance to the yeast model system upon overexpression. We have identified the gene that encodes BvHb2, a class 2 non-symbiotic hemoglobin, which is present as a single copy in the sugar beet genome, expressed mainly in leaves and regulated by light and abiotic stress. We have evaluated its biotechnological potential in the model plant Arabidopsis thaliana and found that BvHb2 is able to confer drought and osmotic stress tolerance. We also generated transgenic lines of tomato (Solanum lycopersicum) overexpressing BvHb2 and found that the resulting plants are more resistant to drought-induce withering. In addition, transgenic lines overexpressing BvHb2 exhibit increased levels of iron content in leaves. Here, we show that class 2 non-symbiotic plant hemoglobins are targets to generate novel biotechnological crops tolerant to abiotic stress. The fact that these proteins are conserved in plants opens the possibility for using Non-GMO approaches, such as classical breeding, molecular breeding, or novel breeding techniques to increase drought tolerance using this protein as a target.</jats:p

Difusión de la ciencia en población vulnerable desde la UCC de la Universidad de Zaragoza: niños hospitalizados, jóvenes en riesgo de exclusión y adultos en centros penitenciarios

Captar el interés del público general por la ciencia puede ser complejo pero no imposible. Hacerlo con públicos desfavorecidos o alejados de los canales habituales de divulgación científica puede ser bastante más difícil pero resulta un reto fascinante. Con investigadores cada vez más comprometidos con la tarea de divulgar y convencidos de su utilidad social, desde la UCC de la Universidad de Zaragoza se han dado pasos decisivos para acercar la ciencia a la ciudadanía. Esto ha ocurrido con el taller de producción del documental científico, iniciado en 2010, de donde surgió “Ciencia de cine” Así, bajo la fórmula de cine fórum, la institución lleva ciencia a cualquier ámbito: centros cívicos, bares, facultades, institutos de Secundaria y colegios de Primaria --también del medio rural--, gracias al debate directo con los 175 científicos autores de 35 minidocumentales. El formato de cine fórum científico resulta idóneo para realizar una difusión de la ciencia muy efectiva y cercana gracias a su flexibilidad para aplicarse en lugares y con espectadores muy diferentes. Tras visionar un minidocumental, el investigador profundiza con la audiencia en los temas planteados, complementando con otras actividades (e.g., experimentos, juegos, debate), lo que fomenta el diálogo y la participación. Los cine fórum son talleres participativos donde la curiosidad y la fascinación de los participantes y la cercanía de los investigadores potencian el aprendizaje a través de metodologías activas. Como ejemplo de esta adaptabilidad se presentan tres experiencias en contextos inusuales y muy diferentes: los centros penitenciarios de Zuera y Daroca, con un público heterogéneo (e.g., edad, formación académica), el Aula del Hospital Infantil del Hospital Universitario Miguel Servet de Zaragoza, para niños de edades entre 4 a 16 años, con notables diferencias de desarrollo madurativo, de conocimientos previos o intereses y cuyos problemas de salud afectan a su capacidad de concentración y aprendizaje, y finalmente jóvenes en riesgo de exclusión con el proyecto “CienciAlternativa” mediante un convenio de colaboración con los ocho centros sociolaborales de la Fundación Adunare

Paestum dietary habits during the Imperial period: archaeological records and stable isotope measurement

In historical contexts, analyses of carbon and nitrogen stable isotopes can be useful to answer different question on dietary behavior and to crosscheck information, drawn from texts and classical archaeological investigations. In this study the Isotope Ratio Mass Spectrometry (IRMS) facility installed at the IRMS-SUN Laboratory of the Second University of Naples is presented. Moreover, results coming from application of stable isotope analyses to bone collagen extracted from human remains of the necropolis of "Porta Sirena" in Paestum will be discussed. Finally, a combined analyses of archaeological and historical record and stable isotope measurements permits to expand our knowledge on diet in Roman Paestum.</p

Selective Dehydrogenation of Formic Acid Catalyzed by Air-Stable Cuboidal PN Molybdenum Sulfide Clusters

Formic acid is considered as a promising hydrogen storage material in the context of a green hydrogen economy. In this work, we present a series of aminophosphino and imidazolylamino Mo3S4 cuboidal clusters which are active and selective for formic acid dehydrogenation (FAD). Best results are obtained with the new [Mo3S4Cl3(ediprp)3](BPh4) (4(BPh4)) (ediprp=(2-(diisopropylphosphino)ethylamine)) cluster, which is prepared through a simple ligand exchange process from the Mo3S4Cl4(PPh3)3(H2O)2 precursor. Under the conditions investigated, complex 4+ showed significantly improved performance (TOF=4048 h−1 and 3743 h−1 at 120 °C in propylene carbonate using N,N-dimethyloctylamine as base after 10 min and 15 min, respectively) compared to the other reported molybdenum compounds. Mechanistic investigations based on stoichiometric and catalytic experiments show that cluster 4+ reacts with formic acid in the presence of a base to form formate substituted species [Mo3S4Cl3-x(OCOH)x(ediprp)3]+ (x=1–3) from which the catalytic cycle starts. Subsequently, formate decarboxylation of the partially substituted [Mo3S4Cl3-x(OCOH)x(ediprp)3]+ (x=1, 2, 3) catalyst through a β-hydride transfer to the metal generates the trinuclear Mo3S4 cluster hydride. Dehydrogenation takes place through protonation by HCOOH to form Mo−H⋅⋅⋅HCOOH dihydrogen adducts, with regeneration of the Mo3S4 formate cluster. This proposal has been validated by DFT calculations.Funding for open access charge: CRUE-Universitat Jaume