Fluxional Behaviour of Phosphole and Phosphine Ligands on Triosmium Clusters

International audienceThe unsaturated cluster [Os3(μ-H)2(CO)10] reacts with a variety of π-conjugated phosphole ligands: 2,5-bis(2-thienyl)-1-phenylphosphole, 2,5-bis(2-pyridyl)-1-phenylphosphole, and 1,2,5-triphenylphosphole, to give the monosubstituted [Os3(μ-H)(H)(CO)10(P)] and [Os3(μ-H)2(CO)9(P)] derivatives. Variable-temperature 1H NMR studies for the decacarbonyltriosmium complexes show that the hydride ligands undergo fluxional behavior and its decarbonylation gave the nonacarbonyl unsaturated species with equivalent hydrides. An X-ray crystallographic analysis of [Os3(μ-H)2(CO)9(P)] (2b) (P = 1,2,5-triphenylphosphole) is reported. From 2,5-bis(2-pyridyl)-1-phenylphosphole four isomers are obtained, the 1H NMR spectrum at low temperature indicates that the phosphole ligand may occupy pseudoaxial and equatorial sites at one of the osmium atoms bearing the bridging hydride. The reaction of [Os3(CO)10(CH3CN)2] with cyanoethyldiphenylphosphine affords mono- and bis(phosphine)-substituted clusters. The X-ray crystal structure of the monosubstituted [Os3(CO)11(η1-PC15H14N)] (3) derivative is discussed. The dynamic behavior observed for [Os3(CO)10(η1-PC15H14N)2] (4) is studied by variable-temperature 1H and 31P{1H} NMR spectroscopy. The latter studies show a mixture of two geometric isomers, which are in dynamic equilibrium at room temperature where the 1,2-trans–trans isomer (4a) is favored, whose molecular structure has been determined by X-ray crystallography

Fosfoles en la química de coordinación

Los fosfoles exhiben una gran versatilidad como ligandos en la química de coordinación. Su estructura y propiedades ha permitido la obtención de una diversidad de complejos interesantes, algunos presentando estructuras y números de coordinación inusuales, tal que pueden ofrecer actividad catalítica o poseer propiedades electrónicas que pueden ser aprovechadas en la electrónica o en la óptica no lineal. Debido a la importancia que presentan los fosfoles, este trabajo se enfoca en su reactividad frente a diferentes complejos mononucleares o agregados metálicos, y sus posibles aplicaciones en las áreas de la catálisis, electroquímica y fotoquí[email protected] exhibit great versatility as ligands in coordination chemistry. Their structure and properties has allowed obtaining a variety of interesting complexes, some of them with unusual structures and coordination numbers, such that can offer catalytic activity or possess electronic properties which can be exploited in electronic or nonlinear optics. Due to the importance presented by phospholes this work focuses on their reactivity with different mononuclear complexes or metallic clusters, and their possible applications in the field of catalysis, electrochemistry and photochemistry

Synthesis, Characterization and Photophysical Properties of a New 2,5-Di(aryl)phosphole Derivative and Their Trigonal Copper-Phosphole Complexes

A new phosphole derivative 2,5-di(2-quinolyl)-1-phenylphosphole (1) was synthesized by using the Fagan-Nugent method. Phosphole was obtained as an air stable solid in high yield (73%). Additionally, two new copper phosphole complexes [CuX(Phosphole)2] (X = Cl (2a), I (2b), Phosphole = 1) have been synthesized by reaction of CuX (X = Cl, I) and phosphole derivative (1). All compound were characterized by NMR, ESI-MS, UV–Vis and fluorescence spectroscopy. The photophysical properties of all compounds were analyzed, UV-Vis spectra of the complexes 2a-b shown π–π* transitions with shift very similar to the found in the free phosphole due to that their symmetrical structures inhibits efficient ILCT. We have found that the compounds 1, 2a-b exhibited fluorescence between 460 and 583 nm with quantum yields of Φf = 0.04 – 0.11. The emission energy of 2b is higher than 2a, suggesting that λmax is affected by the ligand-field strength of the halogen ions in the complexes (I- - ).</div

High variety of coordination modes of π-conjugated phospholes in dinuclear rhenium carbonyls. Fluxional behavior of σ,π-complexes

International audienceA variety of dirhenium carbonyl complexes containing π-conjugated phosphole derivatives were obtained from reaction of [Re2(CO)8(CH3CN)2] with each of the following phospholes: 2,5-bis(2-thienyl)-1-phenylphosphole (btpp), 2,5-bis(2-pyridyl)-1-phenylphosphole (bpypp) and 1,2,5-triphenylphosphole (tpp). The π-conjugated phospholes were found to behave as two-, four- or six-electron donor ligands via σ or σ-π interactions with the metal centers, presenting bridging or chelating coordination modes as determined by spectroscopic methods and single crystal X-ray diffraction analysis. Metal-metal bond cleavage was evidenced when btpp was used, leading to a mono-substituted mononuclear complex. Variable-temperature 1H NMR studies for σ,π-complexes showed a fluxional behavior due to the restricted rotation around the P–C and C–C bonds of the 1,2,5-trisubstituted phosphole ring

¿De qué manera los espacios arquitectónicos educativos de la Institución Educativa Francisco Luis Hernández favorecen y/o limitan el acceso y desplazamiento de los niños y niñas con discapacidades físicas?

Ubicación en Biblioteca USB Medellín (San Benito): CD-2727t .-- Grupo de Investigación Interdisciplinario de Estudios Pedagógicos (GIDEP).-- Línea de Investigación: Pedagogías Críticas.-- Área: Pedagogía.-- Tema: Espacios y formaciónEl presente artículo pretende abordar dos categorías; tales como espacios arquitectónicos educativos y discapacidad física en niños y niñas, mediante las cuales se busca observar en los espacios educativos la accesibilidad, movilidad y adecuaciones a nivel de infraestructura, con el fin de brindar a los niños y niñas con dicha discapacidad, mayor facilidad en el desplazamiento por cada una de las instalaciones de los espacios escolares, realizando con normalidad sus rutinas diarias y actividades programas a nivel pedagógico

Reaction of carbonyl trinuclear clusters with 2,5-bis(2-thienyl)-1-phenyl-phosphole as a ligand: a new pathway to ruthenacyclopentadiene and cyclopentadienone ruthenium complexes

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Reactivity of dirhenium and triruthenium carbonyls toward a biphosphole ligand: M–M, P–P and C–H bonds cleavage

International audienceThe reaction of [Re2(CO)8(CH3CN)2] with bis(2-thienyl)biphosphole in refluxing n-octane affords the complex [Re(CO)3(η5-PC16H14S2)] (1) where cleavage of the Re–Re and P–P bonds occurs; its molecular structure confirms the formation of a rhenium mononuclear compound with a η5-coordinated phospholyl unit and three carbonyl groups oriented in a tripod. On the other hand, bis(2-thienyl)biphosphole reacts with [Ru3(CO)12] in refluxing cyclohexane to affording two new compounds [Ru3(CO)9(μ:η1:η5-PC16H13S2)] (2) and [Ru4(CO)13(μ:η1-PC16H14S2)2] (3). Spectroscopic data and theoretical studies of 2 suggest the formation of an open Ru3 cluster with two metal–metal bonds bridged by a (η1:η5-PC16H13S2) unit and a C-H bond activation of one of the thienyl substituents. X-ray structure of 3 reveals a novel tetranuclear ruthenium cluster containing 13 terminal carbonyl ligands and two phospholyl units coordinated as μ-phosphide

Synthesis of rhenacyclopentadienes and eta(2):eta(2)-diyne complexes from a labile dirhenium carbonyl and pi-conjugated 1,7-octadiynes: Structural and photophysical characterization

A series of dirhenium carbonyl compounds containing pi-conjugated diyne ligands and symmetrical 2,5-bis(aryl)rhenacyclopentadienes has been synthesized by reaction of [Re-2(CO)(8)(CH3CN)(2)] and 1,8bis(aryl)-1,7-octadiyne derivatives [aryl = 2-thienyl (a), 2-pyridyl (b), 2-quinolyl (c) and 9-phenanthrenyl (d)]. We found that diyne ligands undergo coordination to the labile rhenium dinuclear in bridging or chelate modes, however, the formation of metallacyclopentadiene complexes was favorably observed. All products were fully characterized by IR, NMR, ESI-MS, UV-Vis and fluorescence spectroscopy. Single-crystal structures of three new 2,5-bis(aryl) rhenacyclopentadienes [Re-2(CO)(7)(mu-eta(1):eta(1):eta(2):eta(2)-C16H14S2)] (1a), [Re-2(CO)(6)(CH3CN)(mu-eta(1):eta(1):eta(2):eta(2)-C16H14S2)] (2a) and [Re-2(CO)(6)(CH3CN)(mu-eta(1):eta(1):eta(2):eta(2)-C26H20N2)] (2c) are described. DFT calculations were used to evaluate the proposed geometries for the two eta(2):eta(2)-diyne complexes [Re-2(CO)(6)(CH3CN)(2)(mu-eta(2):eta(2)-C18H16N2)] (3b), [Re-2(CO)(6)(CH3CN)(2)(eta(2):eta(2)-C26H20N2)] (4c), and the rhenacyclopentadiene [Re-2(CO)(6)(CH3CN)(mu-eta(1):eta(1):eta(2):eta(C36H26)-C-2)] (2d). The photophysical properties of all complexes were assessed, in that they exhibited fluorescence between 408 and 599 nm with quantum yields of Phi(f) = 0.02-0.09. An exceptional fluorescence quantum yield of Phi(f) = 0.64 was found for [Re-2(CO)(6)(CH3CN)(2)(eta(2):eta(2)-C26H20N2)] (4c), which has been attributed to its rigid chelate structure. This work represents the second example of fluorescent 2,5-bis(aryl)rhenaclyclopendadienes reported up to date8813444CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP310779/2016-22013/22127-2Instituto Venezolano de Investigaciones Cientificas [1082]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESPFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2013/22127-2]; INOMAT - INCT for Science, Technology and Innovation in Functional Complex Materials [2014/50906-9]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPqNational Council for Scientific and Technological Development (CNPq) [310779/2016-2

Novel copper(I) complex of 2,5-Bis(2-pyridyl)phosphole: Synthesis, Characterization, Catalytic Activity and DFT Calculations

A copper(I) complex [CuCl{k1(P)-1a}{k2(P,N)-1a}] (1a = 2,5-bis(2-pyridyl)-1-phenylphosphole) with pseudo tetrahedral geometry was synthesized. In solution, 1a displays a hemilabile behaviour leading to a dynamic equilibrium between four and three-coordinate specie. Its catalytic potential was tested in synthesis of propargylamines and 1,2,3-triazoles via three-component reactions. Experimental results discussed on base to DFT calculations. </p