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111.
Aldo Arrais Eliano Diana Domenica Marabello Giuliana Gervasio Pier Luigi Stanghellini 《Journal of organometallic chemistry》2011,696(11-12):2299-2305
The synthesis of organometal complexes from chromium hexacarbonyl with 1-methyl-naphthalene ligand is reported. Two arene-chromium-tricarbonyl isomers are formed at competitive yields, featured with the metal fragment coordinated to both the methylated and the benzenic aromatic ring. A single-crystal X-ray diffraction measurement has been performed on the [(η6-5,6,7,8,9,10-C11H10)Cr(CO)3] isomer, which presents the metal carbonyl moiety attached to the benzenic arene ligand. The products of reaction have been studied by UV–VIS–NIR, fluorescence and 1H NMR spectroscopies. A detailed vibrational characterisation by mean of experimental FT-IR and Raman spectroscopy and DFT calculations is reported. The electron ligand donation to the metal carbonyl system, determined by FT-IR spectroscopy, has been related to the actual decrease of resonance energy of the aromatic hydrocarbon in the complex and compared with other chromium tricarbonyl complexes of different polycyclic aromatic hydrocarbons provided with the naphthalenic moiety. 相似文献
112.
Giorgetti M Guadagnini L Tonelli D Minicucci M Aquilanti G 《Physical chemistry chemical physics : PCCP》2012,14(16):5527-5537
A deep structural investigation predominantly by X-ray spectroscopic techniques is conducted on films of copper hexacyanoferrate (CuHCF) deposited under different conditions, aimed at establishing structure-properties relationships. We show that the potentiodynamic electrosynthesis of CuHCF on carbon-based surfaces produces a highly disordered material, with a variable amount of Prussian Blue (PB). The subsequent Cu(2+) intercalation induces the partial conversion of PB into CuHCF, which explains the improved electrocatalytic properties after the intercalation process. Both Cu and Fe K-edge data have been recorded. For the sample with the lower amount of PB, we could perform a multiple edge data analysis to determine the local atomic environment around both metal centres using the same set of structural parameters. The presence of high multiplicity Cu-N-C-Fe linear chains has allowed us to determine accurately the local environment of Fe while fitting the Cu K-edge data only. Using this approach we have retrieved structural information around Fe for those samples in which the concomitant presence of PB would have made impossible the analysis of the Fe K-edge. The Fe-C, C-N and Cu-N bond distances have been found in agreement with those of the bulk structures, but higher values of [Fe(CN)(6)] vacancies for the building blocks have been evidenced, reaching a value of ~45% in one sample. XANES, Raman and SEM data agree with the model proposed for each studied electrode. 相似文献
113.
Paolo Ciambelli Maria Sarno Giuliana Gorrasi Diana Sannino Mariarosaria Tortora 《Journal of Macromolecular Science: Physics》2013,52(5):779-795
Nanocomposite materials were prepared by incorporating multiwall carbon nanotubes (MWNTs), obtained by acetylene catalytic chemical vapor deposition (CCVD) on Co/Fe‐modified MgO, within poly(vinyl alcohol) (PVA). Before incorporation, nanotubes were oxidized to obtain better compatibilization with the polymer. It has been found that the addition of COOH‐functionalized and purified MWNTs improves the mechanical response, increases the glass transition temperature, and delays the thermal oxidation of PVA. Furthermore, the PVA crystallinity seems to be enhanced by the presence of nanotubes. 相似文献
114.
Romo Arago Dougu Kentsop Valeria Iobbi Giuliana Donadio Barbara Ruffoni Nunziatina De Tommasi Angela Bisio 《Molecules (Basel, Switzerland)》2021,26(17)
Salvia corrugata Vahl. is an interesting source of abietane and abeo-abietane compounds that showed antibacterial, antitumor, and cytotoxic activities. The aim of the study was to obtain transformed roots of S. corrugata and to evaluate the production of terpenoids in comparison with in vivo root production. Hairy roots were initiated from leaf explants by infection with ATCC 15834 Agrobacterium rhizogenes onto hormone-free Murashige and Skoog (MS) solid medium. Transformation was confirmed by polymerase chain reaction analysis of rolC and virC1 genes. The biomass production was obtained in hormone-free liquid MS medium using Temporary Immersion System bioreactor RITA®. The chromatographic separation of the methanolic extract of the untransformed roots afforded horminone, ferruginol, 7-O-acetylhorminone and 7-O-methylhorminone. Agastol and ferruginol were isolated and quantified from the hairy roots. The amount of these metabolites indicated that the hairy roots of S. corrugata can be considered a source of these compounds. 相似文献
115.
Alain Favre Giuliana Moreno Christian Salet Francloise Vinzens 《Photochemistry and photobiology》1993,58(5):689-694
Monkey kidney cells (CV-1) grown for 4 h in the presence of 0.1 m M 4-thiouridine (s4 Urd) incorporate this photoactivable uridine analog in their RNA. A minor, 5–8%, thiolated RNA fraction can be isolated from bulk RNA by affinity chromatography. This RNA fraction contains 1.5–2.5 s4 Urd residues per 100 nucleotides and exhibits a broad chain length distribution ranging from 700 to 7000 nucleotides. It is essentially of nuclear origin and amounts to 30% of the RNA synthesized during exposure of cells to s4 Urd. Under the same s4 Urd labeling conditions, no thiolated pyrimidine residues have been detected in DNA.
Irradiation with 365 nm light (45 kJ/m2 ) of the cells immediately after s4 Urd exposure triggers long-term inhibition of DNA, RNA and protein synthesis accompanied by a linear decline (50% in 2 days) in the total cell mass of cultured cells. In contrast, exposure to s4 Urd alone results in moderate but reversible inhibitory effects. The available data suggest that s4 Urd-induced photolesions in newly synthesized RNA such as RNA-RNA cross-links as well as RNA-protein bridges are directly involved in impairment of essential cellular functions. 相似文献
Irradiation with 365 nm light (45 kJ/m
116.
Giuliana Borsa Stefania Castelletto Aldo Godone Carlo Novero Maria Luisa Rastello 《Optical Review》1997,4(4):484-489
This work presents a new technique for the measurement of second-order optical nonlinear coefficients from the absolute radiant power of the parametric fluorescence emission. It is based on calibrated detectors regarded as secondary radiometric standards. This technique makes it possible to skip a number of problems usually encountered with standard techniques based on calibrated neutral density filters and reference sources of light at much higher power levels. We infer a value for the d31 nonlinear coefficient of LiIO3 from spectral measurements of the fluorescence power integrated over all solid angles, by denning the wavelength bandwidths with interference filters. Moreover, by performing the measurements on the ultraviolet and visible emission lines of an argon ion laser in the range from 351 to 488 nm, the wavelength dependence of d31 is compared with the expected one obtained by Miller’s dispersion law. 相似文献
117.
118.
119.
Piero Zanello Giuliana OpromollaLuca PardiKeith H. Pannell Hemant K. Sharma 《Journal of organometallic chemistry》1993,450(1-2):193-196
The electrochemical behaviour of the ferrocenylacyl derivatives [FcCOER3] (E = C, Si or Ge; R = Me or Ph) is examined. One-electron oxidations to the substantially stable monocations [FcCOER3]+ occur at potentials significantly higher than that observed with ferrocene, but only minor differences hold within the series, independent of the nature of both E and R. In contrast the EPR spectra of the monocations for E = C show that the unpaired electron resides mainly on the iron, whereas for E = Si or Ge the electron density is essentially localized on the C5H4COER3 fragment. 相似文献
120.
Giuliana Palmieri 《Milan Journal of Mathematics》1995,65(1):335-356
Given a setS and a function σ:S x S→[0, +∞[ such that σ(x, x)=0, we define the generalizedp-energy of a curve γ: [a, b]→S, so that, ifS is a Hilbert space and σ(x, y)=‖x−y‖ we obtain
. Sufficient conditions for the equality of the defined energies are also given. Moreover the case in whichS is a set of measurable parts of ℝn and σr is a family of functions used in order to study the generalized minimizing motions, is discussed.
Conferenza tenuta il 30 ottobre 1995 相似文献
Conferenza tenuta il 30 ottobre 1995 相似文献