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61.
Boccia A Marrani AG Stranges S Zanoni R Alagia M Cossi M Iozzi MF 《The Journal of chemical physics》2008,128(15):154315
We present here the results of a synchrotron radiation-excited UV-photoemission investigation and density functional theory calculations on a structurally related series of organometallic free molecules: ethylferrocene (EtFC), vinylferrocene (VFC), and ethynylferrocene (EFC). This series exemplifies the electronic interactions operating when the C-C substituent group of an aromatic ring is bound to the substrate surface atoms, from a single C-C bond to the double and triple C-C bond pi systems which are still able to preserve substrate-molecule conjugation. A detailed assignment of the gas phase valence photoelectron spectra is discussed, providing new data on the electronic structure of EtFC and EFC and offering a partial reinterpretation of previous assignments on VFC. The broken symmetry of ferrocene caused by the monosubstitution has notable effects on the removal of the molecular orbital (MO) degeneracy which is found to be especially remarkable for the ferrocenelike e(1)' MOs. This effect is ascribed to the interaction between the aromatic cyclopentadyenyl ring and the substituent through sigma/pi hyperconjugation and pi-conjugation mechanisms depending on the nature of the hydrocarbon moiety and its conformational geometry. The vertical ionization energy values of the highest occupied MO for the alkylferrocene and ferrocene free molecules linearly correlate with the redox potential in acetonitrile for ferrocene and the corresponding hybrids obtained by covalently anchoring the free molecule on silicon. 相似文献
62.
P. Melnikov V. A. Nascimento L. Z. Zanoni Consolo 《Journal of Thermal Analysis and Calorimetry》2012,107(3):1117-1121
It is well established that gallium insertion into the hydroxiapatite matrix as practiced in orthopedics protects bone from
resorbtion and improves the biomechanical properties of the skeletal system. The research presented in this article is an
investigation into the thermal decomposition of gallium nitrate, which is part of a complex process leading to the preparation
of a hybrid matrix. It was demonstrated that after melting of the hexahydrate in its own water there occurs a simultaneous
condensation of 4 mol of initial monomer Ga(NO3)3·6H2O into a tetramer Ga4O4(NO3)4. The resulting inorganic cycle gradually loses N2O5 and, through the formation of unstable oxynitrates, is transformed into gallium oxide. The use of molecular mechanics for
comparing the potential energies of consecutive products of thermal decomposition permitted an evaluation of their stability
and an appropriate interpretation of the experimental data. 相似文献
63.
64.
Cardoso JC Grimes CA Feng X Zhang X Komarneni S Zanoni MV Bao N 《Chemical communications (Cambridge, England)》2012,48(22):2818-2820
We report on low-cost, all solution fabrication of efficient air-stable nanostructured thin film photovoltaics comprised of n-type Sb(2)S(3) chemically deposited onto TiO(2) nanowire array films, forming coaxial Sb(2)S(3)/TiO(2) nanowire hybrids vertically oriented from the SnO(2):F coated glass substrate, which are then intercalated with poly(3-hexylthiophene) (P3HT) for hole transport and enhanced light absorption. 相似文献
65.
A Russo M Migliorini L Cecchi C Cherubini M Giusti B Zanoni E Perri M Nardi G Sindona 《Journal of mass spectrometry : JMS》2012,47(9):1242-1246
Identification and assay of sugars in olive drupes during their ripening phase is evaluated by tandem mass spectrometry. Recent achievements have shown that the quality of an extra virgin olive oil can be directly correlated to the ripening degree of the drupes that is likely linked to their saccharides content. An innovation in this peculiar food chain is now proposed that considers a high throughput assessment of the carbohydrate content by a recently introduced protocol based on the gas-phase chemistry of sugar-cesium adducts by ESI-MS/MS. Copyright ? 2012 John Wiley & Sons, Ltd. 相似文献
66.
A new asymmetric approach to the hydroxylactone (+)-(3aR,4R,6aS)-4-(hydroxymethyl)-3a,4-dihydro-3H-cyclopenta[b]furan-2(6aH)-one (1), a key synthetic building block for cis-1,2-disubstituted five-membered ring derivatives (i.e., isoprostanes, jasmonates, and clavulones), has been described. A remarkable control of the absolute and relative configuration of the three stereocenters was achieved. Thus, the use of the Trost's asymmetric allylic alkylation strategy secured highly enantioenriched (R)-3-(nitromethyl)cyclopent-1-ene (13), which was smoothly converted to (R)-cyclopent-2-enecarboxylic acid (15) in excellent yield and high enantiomeric purity (>98% ee). 6-exo-trig atom-transfer radical cyclizations of ((R)-cyclopent-2-enyl)methyl 2-iodoacetate (12) produced exclusively the desired cis-fused delta-lactone (4aR,7aR)-hexahydro-5-iodocyclopenta[c]pyran-3(1H)-one (11), which was subsequently elaborated to hydroxylactone 1 through a stereocontrolled Pd(II)-mediated lactonization reaction. En route to preclavulone A, a putative elusive intermediate in the biosynthesis of clavulones, the synthetic utility of compound 1 was demonstrated. The key feature in this synthesis was the installation of the lower side chain via the Knochel organozinc sp3-sp C-C coupling protocol. 相似文献
67.
P. Melnikov I. V. Arkhangelsky V. A. Nascimento A. F. Silva L. Z. Zanoni Consolo 《Journal of Thermal Analysis and Calorimetry》2014,118(3):1537-1541
Thermal decomposition of samarium nitrate hexahydrate Sm(NO3)3·6H2O has been investigated by thermogravimetry, differential scanning calorimetry, infrared spectroscopy, and X-ray diffractometry. This is a complex process that involves slow dehydration and fast concomitant internal hydrolysis. It is markedly different from the processes described for other members of the lanthanide series. At the first stage, pyrolysis is accompanied by removal of water and nitric acid to form samarium pentahydrate Sm(NO3)3·5H2O and intermediate oxonitrates containing O–Sm–OH groups. No traces of SmONO3 were detected. It is assumed that the existence of intermediate structures with six atoms of samarium best fits the experimental results. At higher temperatures, these products undergo further degradation, lose nitrogen dioxide, water, and oxygen, and finally, after having lost lattice water, are transformed into a cubic form of samarium oxide. 相似文献
68.
Dr. Alice Boccia Dr. Fabio D'Orazi Dr. Elena Carabelli Dr. Rocco Bussolati Prof. Arturo Arduini Prof. Andrea Secchi Dr. Andrea G. Marrani Prof. Robertino Zanoni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(24):7999-8006
The assembly of gold nanoparticles (AuNPs) on a hydrogenated Si(100) surface, mediated by a series of hierarchical and reversible complexation processes, is reported. The proposed multi‐step sequence involves a redox‐active ditopic guest and suitable calix[n]arene‐based hosts, used as functional organic monolayers of the two inorganic components. Surface reactions and controlled release of AuNPs have been monitored by application of XPS, atomic force microscopy (AFM), field‐emission scanning electron microscopy (FESEM) and electrochemistry. 相似文献
69.
70.