Tuning the activity of alternative Ru-based initiators for ring-opening metathesis polymerization of norbornene and norbornadiene by the substituent in 4-CH2R-piperidine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The hypotensive effect of the ruthenium complex [Ru(terpy)(bdq)NO](3+) is higher in male than in female spontaneously hypertensive rats (SHR)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mechanisms underlying the hypotensive and vasodilator effects of Ru(terpy)(bdq)NO](3+), a nitric oxide donor, differ between normotensive and spontaneously hypertensive rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de catalisadores sem platina: estudos comparativos da oxidação de metanol em 'PD''RU'/'C' e 'PT''RU'/'C' em meio alcalino

Pós-graduação em Química - IQ

Antitubercular activity of Ru (II) isoniazid complexes

Despite the resistance developed by the Mycobacterium tuberculosis (MTb) strains, isoniazid (INK) has been recognized as one of the best drug for treatment of Tuberculosis (Tb). The coordination of INH to ruthenium metal centers was investigated as a strategy to enhance the activity of this drug against the sensitive and resistant strains of MTb. The complexes trans-[Ru(NH3)(4)(L)(INH)](2+) (L = SO2 or NH3) were isolated and their chemical and antituberculosis properties studied. The minimal inhibitory concentration (MIC) data show that [Ru(NH3)(5)(INH)](2+) was active in both resistant and sensitive strains, whereas free INK (non-coordinated) showed to be active only against the sensitive strain. The coordination of INH to the metal center in both [Ru(NH3)(5)(INH)](2+) and trans-[Ru(NH3)(4)(SO2)(INH)](2+) complexes led to a shift in the INH oxidation potential to less positive values compared to free INH. Despite, the ease of oxidation of INH did not lead to an increase in the in vitro INH activity against MTb, it might have provided sensitivity toward resistant strains. Furthermore, ruthenium complexes with chemical structures analogous to those described above were synthesized using the oxidation products of INK as ligands (namely, isonicotinic acid and isonicotinamide). These last compounds were not active against any strains of MTb. Moreover, according to DFT calculations the formation of the acyl radical, a proposed intermediate in the INH oxidation, is favored in the [Ru(NH3)(5)(INH)](2+) complex by 50.7 kcal mol(-1) with respect to the free INH. This result suggests that the stabilization of the acyl radical promoted by the metal center would be a more important feature than the oxidation potential of the INH for the antituberculosis activity against resistant strains. (C) 2015 Elsevier B.V. All rights reserved.

Observation of vinylidene emission in mixed phosphine/diimine complexes of Ru(II) at room temperature in solution

The mixed ruthenium(II) complexes trans-[RuCl(2)(PPh(3))(2)(bipy)] (1), trans-[RuCl(2)(PPh(3))(2)(Me(2)bipy)](2), cis-[RuCl(2)(dcype)(bipy)](3), cis-[RuCl(2)(dcype)(Me(2)bipy)](4) (PPh(3) = triphenylphosphine, dcype = 1,2-bis(dicyclohexylphosphino)ethane, bipy = 2,2'-bipyridine, Me(2)bipy = 4,4'-dimethyl-2,2'-bipyridine) were used as precursors to synthesize the associated vinylidene complexes. The complexes [RuCl(=C=CHPh)(PPh(3))(2)(bipy)]PF(6) (5), [RuCl(=C=CHPh)(PPh(3))(2)(Me(2)bipy)]PF(6) (6), [RuCl(=C=CHPh)(dcype)(bipy)]PF(6) (7), [RuCl(=C=CHPh)(dcype)(bipy)]PF(6) (8) were characterized and their spectral, electrochemical, photochemical and photophysical properties were examined. The emission assigned to the pi-pi* excited state from the vinylidene ligand is irradiation wavelength (340, 400, 430 nm) and solvent (CH(2)Cl(2), CH(3)CN, EtOH/MeOH) dependent. The cyclic voltammograms of (6) and (7) show a reversible metal oxidation peak and two successive ligand reductions in the +1.5-(-0.64) V range. The reduction of the vinylidene leads to the formation of the acetylide complex, but due the hydrogen abstraction the process is irreversible. The studies described here suggest that for practical applications such as functional materials, nonlinear optics, building blocks and supramolecular photochemistry. (C) 2011 Elsevier B.V. All rights reserved.

Tailored norbornene-based copolymer with systematic variation of norbornadiene as a crosslinker obtained via ROMP with alternative amine Ru catalysts

Copolymers of norbornene (NBE) with norbomadiene (NBD) were obtained via ROMP with [RuCl2(PPh3)(2)(L)] type complexes as initiators (1 for L = piperidine and 2 for L = 3,5-Me(2)piperidine). The reactions were performed using a fixed quantity of NBE (5000 equivalents/[Ru]) for different concentrations of NBD (500, 1000, 1500 and 2000 equivalents/ [Ru]) in CHCl3, initiated with ethyl diazoacetate at room temperature. The presence of NBD in the NBE chains was characterized by H-1 and C-13 NMR. Whereas the copolymer microstructure was influenced neither by the NBD quantity nor by the initiator type, the N-n and PDI values were improved when increasing the NBD quantity in the medium. When raising the NBD amount, DMA results indicated increased cross-linking with increasing T-g and E ' storage modulus, as well as the fact that SEM micrographs indicated decreased pore sizes in the porous isolated copolymers. (C) 2011 Elsevier Ltd. All rights reserved.

The nature of Ru-NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes-a computational study

Ruthenium complexes including nitrosyl or nitrite complexes are particularly interesting because they can not only scavenge but also release nitric oxide in a controlled manner, regulating the NO-level in vivo. The judicious choice of ligands attached to the [RuNO] core has been shown to be a suitable strategy to modulate NO reactivity in these complexes. In order to understand the influence of different equatorial ligands on the electronic structure of the Ru-NO chemical bonding, and thus on the reactivity of the coordinated NO, we propose an investigation of the nature of the Ru-NO chemical bond by means of energy decomposition analysis (EDA), considering tetraamine and tetraazamacrocycles as equatorial ligands, prior to and after the reduction of the {RuNO}(6) moiety by one electron. This investigation provides a deep insight into the Ru-NO bonding situation, which is fundamental in designing new ruthenium nitrosyl complexes with potential biological applications.

Hypotensive and vasorelaxing effects of the new NO-donor [Ru(terpy)(bdq)NO+](3+) in spontaneously hypertensive rats

Drugs that release nitric oxide (NO) usually have limitations due to their harmful effects. Sodium nitroprusside (SNP) induces a rapid hypotension that leads to reflex tachycardia, which could be an undesirable effect in patients with heart disease, a common feature of hypertension. The nitrosyl ruthenium complex [Ru(terpy)(bdq)NO+](3+) (TERPY) is a NO donor that is less potent than SNP in denuded aortic rings. This study evaluated the hypotension and vasorelaxation induced by this NO donor in Wistar (W) and spontaneously hypertensive rats (SHR) and compared to the results obtained with SNP. Differently from the hypotension induced by SNP, the action of TERPY was slow, long lasting and it did not lead to reflex tachycardia in both groups. The hypotension induced by the NO-donors was more potent in SHR than in W. TERPY induced relaxation with similar efficacy to SNP, although its potency is lower in both strains. The relaxation induced by TERPY is similar in W and SHR, but SNP is more potent and efficient in SHR. The relaxation induced by TERPY is partially dependent on guanylate cyclase in SHR aorta. The NO released from the NO donors measured with DAF-2 DA by confocal microscopy shows that TERPY releases similar amounts of NO in W and SHR, while SNP releases more NO in SHR aortic rings. (c) 2012 Elsevier Inc. All rights reserved.

Synthesis and characterization of [Ru(eta(6)-C10H14)(dppf)X][PF6] (X = Cl, Br, I, SnF3) compounds: The X-ray structure of [Ru(eta(6)-C10H14)(dppf)Cl][SnCl3]center dot 0.45CH(2)Cl(2)

The arene-ruthenium complex [Ru(eta(6)-C10H14)(dppf)Cl]PF6 (1) was used as a precursor for the syntheses of the [Ru(eta(6)-C10H14)(dppf)Br]PF6 (2), [Ru(eta(6)-C10H14)(dppf)I]PF6 (3). [Ru(eta(6)-C10H14)(dppf)SnF3]PF6 (4) and [Ru(eta(6)-C10H14)(dppf)Cl][SnCl3]center dot 0.45CH(2)Cl(2) (5) complexes by its reactions with KBr, Kl, SnF2 and SnCl2. respectively. All of the compounds were characterized by NMR, IR, Fe-57 and Sn-119-Mossbauer spectroscopy, and cyclic voltammetry. The single-crystal X-ray structure analysis of the [Ru(eta(6)-C10H14)(dppf)Cl] [SnCl3]center dot 0.45CH(2)Cl(2) complex revealed the expected piano-stool geometry. Cyclic voltammograms of the complexes showed only one quasi-reversible electrochemical process, involving the oxidation of Fe(II) and Ru(II) at the same potential, which was confirmed by exhaustive electrolysis experiments. Fe-57-Mossbauer parameters obtained for the complexes (1-5) were fitted with one doublet corresponding to a site of one iron(II). The Sn-119-Mossbauer parameters of the complex (4) indicate that tin is tetra covalent. (c) 2012 Elsevier Ltd. All rights reserved.

Droides submarinos, las nuevas fronteras de la exploración del océano. Premio RU Cool (Rutgers University) a la innovación tecnológica en oceanografía 2013

[ES] La Universidad de Rutgers y la Universidad de Las Palmas de Gran Canaria, a través de su Estación de Oceanografía Espacial SEAS Canarias que dirige el Dr. Antonio González Ramos, han colaborado en cinco proyectos de recogida de datos oceánicos desarrollados en el 2008 y el 2013. Estos proyectos son considerados hitos científicos al usar minisubmarinos no tripulados que han batido récords de distancia y tiempo en el agua nunca antes conseguidos. El Dr. González Ramos (Facultad de Ciencias del Mar) recibió el premio en una gala en esta universidad norteamericana, celebrada con motivo del 20 aniversario de su Instituto de Ciencias Marinas y Costeras (RU COOL). González Ramos desarrolló la herramienta Pinzon4D, un sistema de predicción que permite mostrar predicciones de las corrientes oceánicas de 0 a 1000 metros para el mismo día, así como una predicción de tres días, a través de la aplicación Google Earth. La novedad y utilidad de esta herramienta han hecho que se convierta en el protocolo del pilotaje para las dos misiones globales actuales. La herramienta Pinzon-4D se presentará como parte de la Challenger Mission en la próxima sesión plenaria de la Comisión Oceanográfica Internacional (UNESCO). El equipo de trabajo considera que el éxito de este tipo de proyectos radica en tres pilares: la innovación tecnológica, la cooperación internacional y la visibilidad de la información

Trattamento di matrici compostabili da RU mediante biostabilizzazione controllata, presso l'impianto Nuova Geovis, di Sant'Agata Bolognese

La relazione mira ad illustrare l'importanza del compostaggio, quale tecnologia per lo smaltimento dei rifiuti e recupero di risorse. Vengono descritti il processo di stabilizzazione aerobica, i meccanismi microbici e i parametri fisico-chimici che lo caratterizzano. E' evidenziata l'importanza della raccolta differenziata e della scelta delle matrici compostabili nell'ottimizzazione di questa biotecnologia spontanea per il trattamento di rifiuti e reflui organici putrescibili. E' sottolineato, inoltre, come una corretta gestione del processo permetta di valorizzare residui di varia natura trasformandoli in un buon compost, prodotto valido dal punto di vista agronomico e ambientale. Nella parte finale della relazione verrà inoltre descritto un impianto di compostaggio, presente nel territorio regionale, la Nuova Geovis di Sant'Agata Bolognese e dal punto di vista applicativo, verrà  costruito un modello, che permetta di legare l'andamento della temperatura all'andamento dell'IRD, Indice di Respirazione Dinamico, attraverso dati raccolti presso l'impianto, relativi ovviamente a Indice di Respirazione Dinamico (IRD) e temperatura. Questo anche per valutare il corretto del processo stesso.

Complessi tetrazolici di Ru(II) come fotoassorbitori per celle solari di tipo DSSC

Questo lavoro di tesi sperimentale è stato dedicato alla sintesi di alcuni nuovi complessi tetrazolici di Ru(II) e, in collaborazione con il personale dell’istituto ISTEC-CNR di Faenza, al loro impiego come fotoassorbitori per celle solari di tipo DSSC. L’idea progettuale alla base di questa attività è scaturita dalla volontà di modificare la struttura di due coloranti di riferimento (N719 e N749) sostituendo i gruppi tiocianato (SCN-) coordinati al centro metallico con leganti tetrazolici opportunamente funzionalizzati. In questo elaborato si riporta la descrizione e la discussione dettagliata della sintesi dei complessi, della loro caratterizzazione e delle performances delle celle DSSC contenenti tali complessi come fotoassorbitori.

Il concetto del "ma" e la musica di Tōru Takemitsu: traduzione di "The concept of 'ma' and the music of Takemitsu" di Jonathan L. Chenette

Lo scopo di questa tesi è di esplorare l'importanza del concetto giapponese del "ma" nella musica tradizionale, in particolare in quella del compositore Tōru Takemitsu, tramite la traduzione del saggio "The concept of 'ma' and the music of Tōru Takemitsu" (Jonathan L. Chenette, 1982) dall'inglese all'italiano. L'elaborato partirà da un'introduzione generale sul concetto del "ma" nella mentalità giapponese, per proseguire con la biografia di Tōru Takemitsu e una panoramica dei motivi che hanno portato a scegliere la traduzione del saggio di Chenette. Dopo la traduzione in sé e per sé e il commento della stessa, sarà anche fornito in appendice un glossario inglese-italiano della terminologia musicale utilizzata dall'autore all'interno del saggio.

Effect of the Addition of a Fused Donor-Acceptor Ligand on a Ru(II) Complex: Synthesis, Characterization, and Photoinduced Electron Transfer Reactions of Ru(TTF-dppz)(2)(Aqphen) (2+)

The synthesis and the photophysical properties of the complex [Ru(TTF-dppz)(2)(Aqphen)](2+) (TTF = tetrathiafulvalene, dppz = dipyrido-[3,2-a:2',3'-c]phenazine, Aqphen = anthraquinone fused to phenanthroline via a pyrazine bridge) are described. In this molecular triad excitation into the metal ligand charge transfer bands results in the creation of a long-lived charge separated state with TTF acting as electron donor and anthraquinone as terminal acceptor. The lifetime of the charge-separated state is 400 ns in dichloromethane at room temperature. A mechanism for the charge separation involving an intermediate charge-separated state is proposed based on transient absorption spectroscopy.