Synthesis, Photochemical, and Redox Properties of Gold(I) and Gold(III) Pincer Complexes Incorporating a 2,2′:6′,2″-Terpyridine Ligand Framework

Reaction of [Au(C6F5)(tht)] (tht = tetrahydrothiophene) with 2,2′:6′,2″-terpyridine (terpy) leads to complex [Au(C6F5)(η1-terpy)] (1). The chemical oxidation of complex (1) with 2 equiv of [N(C6H4Br-4)3](PF6) or using electrosynthetic techniques affords the Au(III) complex [Au(C6F5)(η3-terpy)](PF6)2 (2). The X-ray diffraction study of complex 2 reveals that the terpyridine acts as tridentate chelate ligand, which leads to a slightly distorted square-planar geometry. Complex 1 displays fluorescence in the solid state at 77 K due to a metal (gold) to ligand (terpy) charge transfer transition, whereas complex 2 displays fluorescence in acetonitrile due to excimer or exciplex formation. Time-dependent density functional theory calculations match the experimental absorption spectra of the synthesized complexes. In order to further probe the frontier orbitals of both complexes and study their redox behavior, each compound was separately characterized using cyclic voltammetry. The bulk electrolysis of a solution of complex 1 was analyzed by spectroscopic methods confirming the electrochemical synthesis of complex 2

Experimental and theoretical evidence of the first Au(I)Bi(III) interaction

3 pages, 3 figures, 1 scheme.-- Published as an advance article on the web 15th Nov. 2006.Complex [Au(C6F5)2][Bi(C6H4CH2NMe2-2)2] 1 displays the first example of an interaction between Au(I) and Bi(III), the nature of which is shown to be consistent with the presence of a high ionic contribution (79%) and a dispersion type (van der Waals) interaction (21%).The D.G.I.(MEC)/FEDER (CTQ2004-05495) project is acknowledged. M. Monge thanks the MEC-UR for his contract ‘‘Ramón y Cajal’’. EC through the Socrates/Erasmus program (M. Nema) and a NATO research fellowship (C. Silvestru) are also acknowledged.Peer reviewe

Unequivocal experimental evidence of the relationship between emission energies and aurophilic interactions

In this paper we describe experimental evidence of the change in emission energy as a function of gold-gold distance. We have employed a luminescent complex exhibiting an aurophilic interaction, which is weak enough to allow its length to be modified by external pressure, but rigid enough to confer structural stability on the complex. By determining the crystal structures and emission characteristics over a range of pressures, we have identified an exponential relationship between the wavelength of the emitted light and the metal-metal distances under pressure. This result can be indirectly related to the repulsive branch of the fitted function representing the energy of the system at different gold-gold distances. The relativistic nature of gold appears to play an important role in the behaviour of this complex

Síntesis y aplicación de nuevas nanopartículas de plata biocompatibles para el control del crecimiento de bacterias lácticas y acéticas en vinos

Este libro recoge el amplio y significativo elenco de estudios (microbiología) recientemente realizados por los grupos de investigación de la red GIENOL (Grupos de investigación enológica).-- et al.Es bien conocido que la plata tiene propiedades antimicrobianas muy potentes. Actualmente, la nanoplata es el nanomaterial más utilizado, representando aproximadamente la cuarta parte de todos los nanomateriales comercializados en el mercado. El presente trabajo tiene por objetivo explorar la potencial utilización de nuevas nanopartículas de plata como agentes antimicrobianos en enología, como una alternativa al empleo de los sulfitos. En primer lugar, se ha llevado a cabo la síntesis y caracterización de dos materiales de plata: PEG‐Ag NPs 1, nanopartículas sólidas soportadas sobre polietilenglicol, y GSH‐Ag NPs 2, nanopartículas en solución soportadas sobre glutatión. A continuación, se ha evaluado su actividad antimicrobiana frente a un total de 11 especies, que incluyen bacterias lácticas y bacterias acéticas. Se han establecido los parámetros de inhibición bacteriana, comprobándose que los nanomateriales con recubrimientos a base de ambos polímeros solubles (polietilenglicol y glutatión), son capaces de inhibir el crecimiento de ambos tipos de bacterias, y en concreto, el efecto inhibidor sobre las bacterias acéticas, fue superior al del metabisulfito potásico. También se ha estudiado el mecanismo de acción antimicrobiano de las nanopartículas de plata, en el que parece que están implicados cambios en la membrana plasmática de la célula bacteriana con pérdida de la viabilidad celular y de las funciones vitales de la célula.Los autores agradecen la financiación recibida del Ministerio de Economía y Competitividad (MINECO) a través de los proyectos PRI‐PIBAR‐2011‐1358 y AGL2012‐40172‐C02‐01.Peer Reviewe

Supplementary data for the article: Ristić, P.; Todorović, T. R.; Blagojević, V.; Klisurić, O. R.; Marjanović, I.; Holló, B. B.; Vulić, P.; Gulea, M.; Donnard, M.; Monge, M.; Rodríguez-Castillo, M.; López-de-Luzuriaga, J. M.; Filipović, N. R. 1D and 2D Silver-Based Coordination Polymers with Thiomorpholine-4-Carbonitrile and Aromatic Polyoxoacids as Coligands: Structure, Photocatalysis, Photoluminescence, and TD-DFT Study. Crystal Growth & Design 2020, 20 (7), 4461–4478. https://doi.org/10.1021/acs.cgd.0c00287

Supplementary material for: [https://pubs.acs.org/doi/10.1021/acs.cgd.0c00287#]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4200]Related to accepted version: [https://cherry.chem.bg.ac.rs/handle/123456789/4203

Preneoplastic somatic mutations including MYD88(L265P) in lymphoplasmacytic lymphoma

Normal cell counterparts of solid and myeloid tumors accumulate mutations years before disease onset; whether this occurs in B lymphocytes before lymphoma remains uncertain. We sequenced multiple stages of the B lineage in elderly individuals and patients with lymphoplasmacytic lymphoma, a singular disease for studying lymphomagenesis because of the high prevalence of mutated MYD88. We observed similar accumulation of random mutations in B lineages from both cohorts and unexpectedly found MYD88(L265P) in normal precursor and mature B lymphocytes from patients with lymphoma. We uncovered genetic and transcriptional pathways driving malignant transformation and leveraged these to model lymphoplasmacytic lymphoma in mice, based on mutated MYD88 in B cell precursors and BCL2 overexpression. Thus, MYD88(L265P) is a preneoplastic event, which challenges the current understanding of lymphomagenesis and may have implications for early detection of B cell lymphomas

Synthesis of gold(III) complexes of 2-(diphenylthiophosphino)aniline

8 páginas, 2 figuras, 3 tablas, 1 esquema.The gold(III) complex [Au(C6F5)2(SPNH2)]CIO4 (1) containing the S,N-donor ligand 2-(diphenylthiop hosphino)aniline (S=PNH2) can be easily prepared by treatment of S=PNH2 with [Au(C6F5)2(OEt2)2]CIO4 and deprotonated with PPN(acac) to afford [Au(C6F5)2(SPNH)] (2). Complex 2 can also be obtained in a one-step reaction from SPNH2 and [Au(C6F5)2(acac)]. The electronic density in excess in 2 can be employed to incorporate a new metallic fragment to give the mixed complexes [Au(C6F5)2SPNH(MPPh3)]CIO4 (M=Au (3), Ag (4)). The crystal structures of 1 and 2 have been determined by X-ray diffraction, showing that the electronic density in excess in complex 2 is located in the Au-N-C fragment.The D.G>I.MEC/FEDER (CTQ2007-67273-C02-02) is thanked for financial support.Peer reviewe

Design of Anisotropic Plasmonic Nanostructures for Light-to-Energy Conversion Applications

The thorough control over the synthetic conditions for the preparation of metallic nanoparticles is essential to achieve the tuning of the shape, size and composition. These characteristics are intimately related to their optical, catalytic and biological properties. A straight methodology consists of the mild reduction of organometallic complexes in the presence of stabilising ligands, which also act as growth directing agents, favouring the anisotropic growth of new nanostructures. [1,2]Thus, a heterometallic gold(I)-silver(I) precursor, [Au2Ag2(C6F5)4(Et2O)2]n, in the presence of oleic acid (OA) leads to the formation of bimetallic wavy nanorods of controlled dimensions. These new nanostructures have a strong plasmonic absorption in the NIR region, arising from the longitudinal surface plasmon resonance mode, around 1500 nm. This plasmonic absorption can be tuned by controlling the nanorod length, which is modified by changing the stoichiometric ratio between the precursor and the OA growth directing agent. The obtained nanostructures have a potential interest for their use in different photocatalytic and biological applications (see Figure).On the other hand, these nanostructures have been functionalized with PEG-SH polymer or grafted on different substrates, such as the 2D semiconductor carbon nitride (C3N4) or an insulator, like silica nanoparticles. The biocompatible functionalization provides the possible application of these nanostructures in photothermal therapy, whereas the deposition on active surfaces permits their use in photocatalytic reduction reactions as well as on light-to-thermal energy applications (see Figure)

Gold-heterometal complexes. Evolution of a new class of luminescent materials.

A very promising area of research in which metallophilic attraction has become the dominating factor determining the structural patterns that give rise to luminescent materials is discussed. In addition to the intrinsic conditions that a gold complex requires to show luminescence, we show how the type and number of the ligands, the coordination environments around the metal centres, the temperature, the heterometal, the metal-metal distances, etc., increase the possibilities of electronic transitions and, hence, multiply the factors that affect the energy and number of emissions. We think that far from being a hindrance or a problem these findings actually give rise to a fascinating area of research with promising future applications, for instance, in imaging technology, vapour sensors, light emitting devices or even medicine, where the demand for optoelectronic devices is increasing every day.Peer reviewe