Synthesis, properties, and some rhodium, iridium, and platinum complexes of a series of bulky m-terphenylphosphine ligands

A series of sterically demanding aryl phosphine ligands (L) bearing terphenyl substituents, PR2Ar′ (R = hydrocarbyl, Ar′ = 2,6-diarylphenyl radical) has been prepared and characterized. The stability of these ligands towards oxidation in the air has been tested, and theoretical and experimental studies aimed to provide information on their electronic and steric properties have been performed. Treatment of the metal dimers [MCl(COD)]2(M = Rh, Ir; COD = 1,5-cyclooctadiene) with ligands PMe2ArXyl2(L1) and PMe2ArDipp2(L5), in a 1:1 metal:ligand ratio, afforded the expected square-planar 16-electron complexes [MCl(COD)(PMe2ArXyl2)] and [MCl(COD)(PMe2ArDipp2)], respectively. These compounds were readily converted into the corresponding dicarbonyl derivatives, [MCl(CO)2(PMe2ArXyl2)] and [MCl(CO)2(PMe2ArDipp2)], respectively. While the expected κ1-P coordination mode of the PR2Ar′ ligands is found for these rhodium and iridium species, the mononuclear Pt(II) derivative obtained by reaction of PtCl2with PMe2ArDipp2has composition [PtCl2(PMe2ArDipp2)], and exhibits a bidentate κ1-P, η1-arene coordination mode involving one of the ipso carbon atoms of a flanking terphenyl aryl ring. The corresponding carbonyl compound [PtCl2(CO)(PMe2ArDipp2)], was generated under a CO atmosphere and exhibits κ1-P coordination mode.Ministerio de Ciencia CTQ2013-42501-P, CTQ2014-51912-REDC, CTQ-2014-52769-C3-3-RJunta de Andalucía FQM-119 P09-FQM-4832, FQM-2126European Union 26722

Synthesis, Structure and Nickel Carbonyl Complexes of Dialkylterphenyl Phosphines

The experimental and computational characterization of a series of dialkylterphenyl phosphines, PR2Ar′ is described. The new P‐donors comprise five compounds of general formula PR2Arurn:x-wiley:09476539:media:chem201803598:chem201803598-math-0001 (R=Me, Et, iPr, c‐C5H9 and c‐C6H11); Arurn:x-wiley:09476539:media:chem201803598:chem201803598-math-0002 = 2,6‐C6H3‐(3,5‐C6H3‐(CMe3)2)2), and another five PR2Ar′ phosphines containing the bulky alkyl groups iPr, c‐C5H9 or c‐C6H11, in combination with Ar′=Arurn:x-wiley:09476539:media:chem201803598:chem201803598-math-0003 , Arurn:x-wiley:09476539:media:chem201803598:chem201803598-math-0004 , or Arurn:x-wiley:09476539:media:chem201803598:chem201803598-math-0005 (L1–L10). Steric and electronic parameters have been determined computationally and from IR and X‐ray data obtained for the phosphines and for some derivatives, including tricarbonyl and dicarbonyl nickel complexes, Ni(CO)3(PR2Ar′) and Ni(CO)2(PR2Ar′). In the solid state, the free phosphines PR2Ar′ adopt one of the three possible structures formally related by rotation around the Cipso−P bond. Details on their relative energies and on the influence of the free phosphine structure on its coordination chemistry towards Ni(CO)n (n = 2, 3) fragments has been obtained by experimental and computational methods.Ministerio de Economía y Competitividad CTQ2013-42501-P, CTQ2016-75193-P, CTQ2017-82893-C2-2-

Risk Factors for COVID-19 in Inflammatory Bowel Disease: A National, ENEIDA-Based Case–Control Study (COVID-19-EII)

(1) Scant information is available concerning the characteristics that may favour the acquisition of COVID-19 in patients with inflammatory bowel disease (IBD). Therefore, the aim of this study was to assess these differences between infected and noninfected patients with IBD. (2) This nationwide case-control study evaluated patients with inflammatory bowel disease with COVID-19 (cases) and without COVID-19 (controls) during the period March-July 2020 included in the ENEIDA of GETECCU. (3) A total of 496 cases and 964 controls from 73 Spanish centres were included. No differences were found in the basal characteristics between cases and controls. Cases had higher comorbidity Charlson scores (24% vs. 19%; p = 0.02) and occupational risk (28% vs. 10.5%; p < 0.0001) more frequently than did controls. Lockdown was the only protective measure against COVID-19 (50% vs. 70%; p < 0.0001). No differences were found in the use of systemic steroids, immunosuppressants or biologics between cases and controls. Cases were more often treated with 5-aminosalicylates (42% vs. 34%; p = 0.003). Having a moderate Charlson score (OR: 2.7; 95%CI: 1.3-5.9), occupational risk (OR: 2.9; 95%CI: 1.8-4.4) and the use of 5-aminosalicylates (OR: 1.7; 95%CI: 1.2-2.5) were factors for COVID-19. The strict lockdown was the only protective factor (OR: 0.1; 95%CI: 0.09-0.2). (4) Comorbidities and occupational exposure are the most relevant factors for COVID-19 in patients with IBD. The risk of COVID-19 seems not to be increased by immunosuppressants or biologics, with a potential effect of 5-aminosalicylates, which should be investigated further and interpreted with caution

A dicoordinate gold(I)–ethylene complex

The use of the exceptionally bulky tris-2-(4,40-di-tert-butylbiphenylyl) phosphine ligand allows the isolation and complete characterization of the first dicoordinate gold(I)–ethylene adduct, filling a missing fundamental piece on the organometallic chemistry of gold. Besides, the bonding situation of this species has been investigated by means of state-of-the-art Density Functional Theory (DFT) calculations indicating that p-backdonation plays a minor role compared with tricoordinate analoguesPeer reviewe

Reactivity of a gold(I)/platinum(0) frustrated Lewis pair with germanium and tin dihalides

This article is part of the themed collection: Inorganic chemistry of the p-block elements.The reactivity of germanium and tin dichlorides with a transition metal-only frustrated Lewis pair based on Au(I) and Pt(0) compounds bearing bulky phosphine ligands is described in this work. We have examined both the reactivity of tetrylene dihalides towards the individual components of the metallic pair, as well as under metal/metal cooperative conditions. These studies allowed us to isolate several uncommon homo- and heterometallic structures. Computational methods have been employed to investigate the bonding scheme of one of these highly-reduced metallic aggregates. In addition, we have developed a tin-promoted strategy to access heteroleptic diphosphine platinum(0) compounds.This work has been supported by the European Research Council (ERC Starting Grant, CoopCat, Project 756575). J. J. M. thanks the Universidad de Sevilla for a research grant.We acknowledge support of the publication fee by the CSIC Open Access Support Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

Sociedad naturaleza y turismo

Naturaleza y turismo parecen el pasado, pero todo es relativo ya que la naturaleza como tal no se aplica directamente en el turismo, este la transforma, la hace más amable y menos riesgosa, por ello hay quienes han planteado lo opuesto: diseñarla desde el inicio para crear un producto turístico a la medida. Sociedad naturaleza y turismo contienen una colección de ensayos presentados en el IV Seminario Internacional Nuevas Alternativas del Turismo, por un grupo de expertos en las ciencias sociales que plantean un conjunto de ideas sobre la creación y transformación de producto turístico

Anales de Edafología y Agrobiología Tomo 31 Número 3-4

Mineralogía de arcillas de sedimentos cuaternarios de la cuenca del Ebro (Zaragoza). I, por C. Rodríguez-Pascual, E. Martínez Reyes y J. García Vicente.-- Sistemas microbioquímicos constituidos por Thiobacillus thiooxidans, azufre y hierro, por A. Ortuño, A. Hernansáez y M. Parra.-- Extracción y determinación de diversas fracciones ácidas en hojas de citrus, por O. Carpena, F. Costa, S. Navarro y J. M. López.-- Suelos de Sierra Morena occidental. II. Mineralogía de las arcillas, por N. Bellinfante y G. Paneque.-- Mineralogía de tierras pardas sobre rocas graníticas de la región occidental gallega, por M. C. Villar y F. Guitián Ojea.-- Nutrición mineral en prumus. Melocotonero, por L. Egea, O. Carpena y T. Berenguer.-- Absorption and translocation of Na in oats (Avena sativa L.) and safflower (Carthamus tinctorius L.), por J. M Pozuelo and Mª R. Felipe.-- Falta de respuesta a la fertilización fosfatada en una tierra negra andaluza con bajo contenido en fósforo total, por P. de Arámbarri.-- Estudio de la acción del ácido húmico sobre la remolacha azucarera utilizando cultivo hidropónico, por Mª P. Sánchez Conde, B. C. Ortega y Mª l. Pérez Brull.-- Evoluciones y relaciones fisiológicas de bioelementos en hoja de prumus persica, por A. Ortuño, M. Parra, A. M. Hernansáez y T. Armero.-- Procesos ele humificación dinámica microbiana y catenas de suelos en la Sierra de Guadarrama, por F. Vellasco de Pedro y J. M. Lozano Calle.-- Compuestos fenólicos en suelos de brezal, por A. Ballester, J. Arines y E. Vieitez.-- Notas.-- Semana de Estudios de la Academia Pontificia de Ciencias ele la Ciudad del Vaticano, sobre: Uso de fertilizantes y su efecto en el rendimiento de la producción, con especial atención a la calidad y economía.-- Nuevos Consejeros del Patronato.-- Representante y coinvestigadores en la C. O. N. I. E.-- VI Reunión del Grupo Español ele Sedimentología.-- Laboratorio de Micromorfología del Suelos.-- II Reunión Nacional de Centros ele Investigación Ganadera del C. S. I. C..-- Congresos y reuniones internacionales.-- Resolución ele los Tribunales del concurso oposición de colaboradores científicos.-- BibliografíaPeer reviewe

Synthesis, properties, and some rhodium, iridium, and platinum complexes of a series of bulky m-terphenylphosphine ligands

A series of sterically demanding aryl phosphine ligands (L) bearing terphenyl substituents, PRAr′ (R = hydrocarbyl, Ar′ = 2,6-diarylphenyl radical) has been prepared and characterized. The stability of these ligands towards oxidation in the air has been tested, and theoretical and experimental studies aimed to provide information on their electronic and steric properties have been performed. Treatment of the metal dimers [MCl(COD)](M = Rh, Ir; COD = 1,5-cyclooctadiene) with ligands PMeAr(L1) and PMeAr(L5), in a 1:1 metal:ligand ratio, afforded the expected square-planar 16-electron complexes [MCl(COD)(PMeAr)] and [MCl(COD)(PMeAr)], respectively. These compounds were readily converted into the corresponding dicarbonyl derivatives, [MCl(CO)(PMeAr)] and [MCl(CO)(PMeAr)], respectively. While the expected κ-P coordination mode of the PRAr′ ligands is found for these rhodium and iridium species, the mononuclear Pt(II) derivative obtained by reaction of PtClwith PMeArhas composition [PtCl(PMeAr)], and exhibits a bidentate κ-P, η-arene coordination mode involving one of the ipso carbon atoms of a flanking terphenyl aryl ring. The corresponding carbonyl compound [PtCl(CO)(PMeAr)], was generated under a CO atmosphere and exhibits κ-P coordination mode.Peer Reviewe