Search results for "TRIM"
showing 10 items of 1942 documents
Synthesis and reactivity of new mono- and dinuclear niobium and tantalum imido complexes: X-ray crystal structure of [Ta(η5-C5H4SiMe3)Cl2{NC6Me4-4-(N…
2006
Abstract The reaction of [1,4-{SiMe3(H)N}2C6Me4] (1) with 2 equivalents of LiBun followed by the addition of SiMe3Cl gave the diamine compound [1,4-{(SiMe3)2N}2C6Me4] (2). [Ta(η5-C5H4SiMe3)Cl4] reacts with 2, in a 2:1 stoichiometric ratio, to initially yield a mixture of the dinuclear, [{Ta(η5-C5H4SiMe3)Cl2}2(μ-1,4-NC6Me4N)] (3), and mononuclear, [Ta(η5-C5H4SiMe3)Cl2{ NC6Me4-4-(N(SiMe3)2)}] (4), imido complexes. 3 can be obtained exclusively by submitting the reaction mixture to repeated cycles of evacuation, to remove volatiles, followed by addition of solvent and subsequent heating. The mononuclear imido complex 4 was isolated from the reaction of [Ta(η5-C5H4SiMe3)Cl4] with 2 in a 1:1 sto…
Hindering the formation of ferrocenes: mono(cyclopentadienyl)halo iron complexes [Fe(C5R5)X] containing a sterically bulky cyclopentadienyl ligand
2001
Abstract The reaction of lithium 1,2,4-tris(trimethylsilyl)cyclopentadienide Li(Si 3 Cp) with ferrous halide FeX 2 (X=Cl, Br, I) in THF at −95 °C gives a thermally extremely sensitive compound that can be regarded as a functional equivalent for the 14-electron fragment [Fe(Si 3 Cp)X]. Experiments to trap this species with TMEDA gives thermally sensitive, colorless, paramagnetic crystals of the composition [LiFe(Si 3 Cp)Cl 2 (TMEDA) 3 ]. Trimethylphosphite gives isolable 18-electron half-sandwich complexes [Fe(Si 3 Cp){P(OMe) 3 } 2 X]. [Fe(Si 3 Cp)X] is also formed by reducing the ferric derivative [Fe(Si 3 Cp)Cl 2 ] with zinc. Analogous reactivity towards ferrous halides is observed for the…
Syntheses and properties of some exo,exo-bis(isodicyclopentadienyl)titanium low-valent complexes
2002
Abstract The paramagnetic compounds exo,exo-bis(η5-isodicyclopentadienyl)chlorotitanium(III) (3) and its analogue with trimethylsilyl-substituted isodicyclopentadienide (isodiCp) ligand (4), and the similar pair of diamagnetic exo,exo-bis(isodicyclopentadienyl)[η2-bis(trimethylsilyl)ethyne]titanium(II) complexes 5 and 6 were obtained by common reduction procedures from exo,exo-bis(isodicyclopentadienyl)titanium(IV) dichloride (1) and exo,exo-bis[η5-2-(trimethylsilyl)isodicyclopentadienyl]titanium(IV) dichloride (2), respectively. As indicated by ESR spectroscopy compound 3 is a dimer in the solid state and in frozen toluene glass but monomeric in toluene solution. Compound 4 is monomeric in…
Preparation and nonlinear optics of monodisperse oligo(1,4-phenyleneethynylene)s
2001
Oligo(1,4-phenyleneethynylene)s 1a−e, with solubilizing propoxy side chains, were prepared by use of Hagihara−Sonogashira coupling reactions. The synthetic strategy was based on a building block system and on the use of trimethylsilyl and triisopropylsilyl protecting groups that could be cleaved selectively. The extension of the conjugation with an increasing number of repeat units provokes a bathochromic shift of the long wavelength absorption and a superlinear increase of the second hyperpolarizability |γ|. The corresponding third harmonic generation (THG) measurements were performed using polystyrene matrices and variable laser wavelengths. We conclude that the conjugation length is much…
Trimetilamīna-N-Oksīda saistība ar metabolisko sindromu pacientiem ar paaugstinātu kardiovaskulāro risku
2016
Ievads. Trimetilamīna-N-oksīds (TMAO) ir jauns kardiovaskulārā riska marķieris, kura metabolisms un riska asociācijas mehānismi ir neskaidri. Ir zināms, ka TMAO līmenis ir augstāks pacientiem ar 2. tipa cukura diabētu, bet tā saistība ar metabolisko sindromu (MS) ir maz pētīta. Mērķis. Noskaidrot, vai pastāv TMAO līmeņa saistība ar MS pacientiem ar paaugstinātu kardiovaskulāro risku. Metodes. Šis ir viena centra novērojošs šķērsgriezuma pētījums, kurā tika iekļauti pacienti pēc specifiski izstrādāta pētījuma dizaina, lai optimāli izvērtētu visus TMAO līmeni ietekmējošos faktorus. Datu statistiskā apstrāde tika veikta ar SPSS programmas 20.0 versiju. Rezultāti. No kopā iekļautajiem 163 pacie…
Persistent radicals of trivalent tin and lead.
2008
In this report we present synthetic, crystallographic, and new electron paramagnetic resonance (EPR) spectroscopic work that shows that the synthetic route leading to the recently reported, first persistent plumbyl radical *PbEbt3 (Ebt = ethylbis(trimethylsilyl)silyl), that is, the oxidation of the related PbEbt3-anion, was easily extended to the synthesis of other persistent molecular mononuclear radicals of lead and tin. At first, various novel solvates of homoleptic potassium metallates KSnHyp3 (4a), KPbHyp3 (3a), KSnEbt3 (4b), KPbIbt3 (3c), and KSnIbt3 (4c) (Hyp = tris(trimethylsilyl)silyl, Ibt = isopropylbis(trimethylsilyl)silyl), as well as some heteroleptic metallates, such as [Li(OE…
ITALIE-TUNISIE: LE PROJET A.P.E.R.
2012
In the range of Transboundary Cooperation Italy-Tunis 2007-2012, the A.P.E.R. Project of Punic, Hellenistic and Roman domestic architecture: safeguarding and valorization, was financed by the European Community. The partnership of the project is composed byfour partners: two Italians and two Tunisians. The principal purpose of Tunisian-Italian Consortium is the material and immaterial preservation and valorization of archaeological sites of Carthage and Kerkouane in Cap Bon,Tunisia and of the Hellenistic-Roman Quarter in the Valley of the Temples in Agrigento, Sicily.
La seda valenciana: turismo de patrimonio
2018
La Comunitat Valenciana cuenta con sólidos elementos patrimoniales relacionados con la seda. Patrimonio inmaterial como las fiestas de las Fallas, patrimonio material como la Lonja de la Seda, ambas reconocidas por la UNESCO como Patrimonio Mundial, e infinidad de otros patrimonios materiales o inmateriales de alto valor se reparten a lo largo del territorio. La combinación de todos estos elementos podría permitir la definición y diseño de un producto turístico de alto valor. En los últimos años, el turismo de Patrimonio Mundial Inmaterial se está consolidando como un segmento de marca específico dentro del turismo patrimonial cuyas características es preciso analizar y valorar para poder d…
Approdi e porti turistici
2004
Se si vuole lanciare la portualità nautica del Mezzogiorno, sfruttando una risorsa turistica dalle enormi potenzialità, è inutile pensare ad un mega piano di nuove edificazioni, mentre è invece indispensabile concentrare risorse, attenzioni e progettualità sul marketing. Il vero problema del Mezzogiorno non è tanto la carenza infrastrutturale, che pure esiste e spesso si concretizza in porti e marine inadeguate ai compiti che dovrebbero e potrebbero svolgere, bensì l'incapacità di mettere in rete le risorse esistenti (molte delle quali in stato di abbandono o comunque sottoutilizzate) e di "venderle" ai potenziali utilizzatori. La nautica oggi non è più un fenomeno di élite ma un impiego de…
Agricoltura e turismo a Ustica. Tipicità, tradizioni e patrimonio culturale
2020
Negli ultimi anni abbiamo assistito a un aumento graduale e progressivo di consapevolezza e di presa di coscienza rispetto all'importanza ed al valore dell'agricoltura, con un interesse sempre maggiore da parte di molteplici categorie di persone verso i prodotti di nicchia e le tipicità locali. In questo breve articolo, partendo dalla mia attuale esperienza di ricerca sul campo sull'isola di Pantelleria, vorrei tracciare degli spunti di riflessione sui concetti di “tipicità”, “tradizioni” e “patrimonio culturale”, nell'ottica di una possibile prospettiva di ricerca da intraprendere sul territorio di Ustica. Quando parliamo di patrimonio culturale, ci riferiamo a qualcosa di estremamente vas…