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101.
Parisi Filippo Bernardini Federico Cavallaro Giuseppe Mancini Lucia Milioto Stefana Prokop David Lazzara Giuseppe 《Journal of Thermal Analysis and Calorimetry》2020,141(3):981-989
Journal of Thermal Analysis and Calorimetry - Filling a polymer with halloysite nanotubes is considered a promising strategy to generate nanocomposites with tailored physicochemical properties. We... 相似文献
102.
103.
S. Mancini A. Gatti L. Lugiato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,12(3):499-508
We study the noiseless amplification of an optical image by means of a confocal cavity containing a parametric medium. We
demonstrate, in the ideal situation, the possibility of preserving the signal-to-noise ratio while amplifying uniformly the
entire image. Some specific effects, which may degrade the performances of the scheme, are taken into account.
Received 23 March 2000 相似文献
104.
Mancini I Guella G Frostin M Hnawia E Laurent D Debitus C Pietra F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(35):8989-8994
Reported here is the first polyarsenic compound ever found in nature. Denominated arsenicin A, it was isolated along a bioassay-guided fractionation of the organic extract of the poecilosclerid sponge Echinochalina bargibanti collected from the north-eastern coast of New Caledonia. In defining an adamantine-type polyarsenic structure for this compound, deceptively simple NMR spectra were complemented by extensive mass spectral analysis. However, it was only the synthesis of a model compound that provided the basis to discriminate structure 4 from other spectrally compatible structures for arsenicin A; to this end, a comparative ab initio simulation of IR spectra for the natural and the synthetic compounds was decisive. Arsenicin A is endowed with potent bactericidal and fungicidal activities on human pathogenic strains. All this may revive pharmacological interest in arsenic compounds while prompting us to rethink the arsenic cycle in nature. 相似文献
105.
Ana M. Costero Prof. Dr. Margarita Parra Dr. Salvador Gil Dr. Raúl Gotor Pedro M. E. Mancini Prof. Dr. Ramón Martínez‐Máñez Prof. Dr. Félix Sancenón Dr. Santiago Royo 《化学:亚洲杂志》2010,5(7):1573-1585
A family of azo and stilbene derivatives ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ) are synthesized, and their chromo‐fluorogenic behavior in the presence of nerve‐agent simulants, diethylchlorophosphate (DCP), diisopropylfluorophosphate (DFP), and diethylcyanophosphate (DCNP) in acetonitrile and mixed solution of water/acetonitrile (3:1 v/v) buffered at pH 5.6 with MES, is investigated. The prepared compounds contain 2‐(2‐N,N‐dimethylaminophenyl)ethanol or 2‐[(2‐N,N‐dimethylamino)phenoxy]ethanol reactive groups, which are part of the conjugated π‐system of the dyes and are able to give acylation reactions with phosphonate substrates followed by a rapid intramolecular N‐alkylation. The nerve‐agent mimic‐triggered cyclization reaction transforms a dimethylamino group into a quaternary ammonium, inducing a change of the electronic properties of the delocalized systems that results in a hypsochromic shift of the absorption band of the dyes. Similar reactivity studies are also carried out with other “non‐toxic” organophosphorus compounds, but no changes in the UV/Vis spectra were observed. The emission behaviour of the reagents in acetonitrile and water–acetonitrile 3:1 v/v mixtures is also studied in the presence of nerve‐agent simulants and other organophosphorous derivatives. The reactivity between 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 and DCP, DCNP, or DFP in buffered water–acetonitrile 3:1 v/v solutions under pseudo first‐order kinetic conditions, using an excess of the corresponding simulant, are studied in order to determine the rate constants (k) and the half‐life times (t1/2=ln2/k) for the reaction. The detection limits in water/acetonitrile 3:1 v/v are also determined for 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 and DCP, DCNP, and DFP. Finally, the chromogenic detection of nerve agent simulants both in solution and in gas phase are tested using silica gel containing adsorbed compounds 1 , 2 , 3 , 4 , or 5 with fine results. 相似文献
106.
Lucia Ambrosio M. Carla Aragoni Dr. Massimiliano Arca Dr. Francesco A. Devillanova Prof. Michael B. Hursthouse Prof. Dr. Susanne L. Huth Dr. Francesco Isaia Prof. Vito Lippolis Prof. Dr. Annalisa Mancini Dr. Anna Pintus Dr. 《化学:亚洲杂志》2010,5(6):1395-1406
The tetrabutylammonium (TBA+) salts of square‐planar monoanionic gold complexes of the unsymmetrically substituted Ar,H‐edt2? 1,2‐dithiolene ligands (Ar,H‐edt2?=arylethylene‐1,2‐dithiolato; Ar=phenyl ( 1 ?), 2‐naphthyl ( 2 ?), and 1‐pyrenyl ( 3 ?)) were synthesized and characterized by spectroscopic and electrochemical methods and the corresponding neutral species ( 1 , 2 , and 3 , respectively) were obtained in CH2Cl2 solution at room temperature by diiodine oxidation. The single‐crystal X‐ray diffraction structural data collected for (TBA+)( 2 ?), supported by DFT theoretical calculations, are consistent with the ene‐1,2‐dithiolate form of the ligand and the AuIII oxidation state. All complexes feature intense near‐IR absorptions (at about 1.5 μm) in their neutral states and Vis‐emitting properties in the 400–550 nm range, the energy of which is controlled by the charge of the complex in the case of the 3 ?/ 3 couple. The spectroscopic and electrochemical features of 1 x? and 2 x? (x=0, 1), both in their cis and trans conformations, were investigated by means of DFT and time‐dependent (TD) DFT calculations. 相似文献
107.
De Martino L Formisano C Mancini E De Feo V Piozzi F Rigano D Senatore F 《Natural product communications》2010,5(12):1969-1976
The essential oils of four Teucrium species were studied and 131 components, in all, were identified. All oils were rich in sesquiterpenes (50.0-61.9%). Caryophyllene and caryophyllene oxide were the main components of Teucrium arduini; germacrene D, delta-cadinene and gamma-cadinene predominated in Teucrium maghrebinum. Carvacrol and caryophyllene predominated in Teucrium polium ssp. capitatum, while carvacrol, caryophyllene oxide and caryophyllene were the most abundant components in Teucrium montbretii ssp. heliotropiifolium. The germination of radish and garden cress was less sensitive to the four essential oils. The radicle elongation, above all, of radish was significantly inhibited by all oils, in particular by the essential oil of T. arduini, at the highest doses tested. Among the main components of the oils, monoterpenes resulted the more active compounds. 相似文献
108.
109.
Ines Mancini Graziano Guella Marino Cavazza Francesco Pietra 《Helvetica chimica acta》1990,73(3):652-658
The 1,4-addition of vinylmagnesium bromide/CuBr-SMe2 to (+)-(4s)-cryptone ((+)- 6 ) in THF in the presence of Me3SiCI gives the silylenol ether 7 which partly undergoes hydrolysis to ketone 8 on aqueous workup; residual 7 is hydrolyzed with pyridinium p-toluenesulfonate (PyTsOH) to give 8 which is protected in situ with ethylene glycol and then ozonolized to give aldehyde (? )- 10. The latter, on addition of 3-lithiofuran followed by dehydration and deprotection with Py TsOH, gives the unnatural (4S)-enantiomer (+)- 2 of noroxopenlanfuran. All processes, except 11 → (+)- 2 , are of good yield. On the basis of previous chemical transformations, this also establishes the (4R)-configuration for penlanfuran ((?)- 1 ) and other sesquiterpenoids of the sponge Dysidea fragilis from the North-Brittany sea. Non viable routes to (±)-noroxoperlanfuran ((±)-2) are also discussed. 相似文献
110.
Graziano Guella Giuseppe Chiasera Ines Mancini Francesco Pietra 《Helvetica chimica acta》1991,74(4):774-786
Temperature-dependent 1H- and 13C-NMR spectra reveal that polyhalogenated marine β-chamigrenes or synthetic derivatives thereof which are trans-diequatorially, substituted at C(8) and C(9), such as rogiolol ((?)- 2 ), obtusol ((+)- 3 ), and their acetates (+)- 1 and (?)- 4 , undergo slow ring- A chair-chair inversion. Conformational equilibria and kinetics are investigated with the aid of synthetic model compounds and molecular-mechanics calculations. Thus, steric repulsions between Brax–C(2) and Heq–C(7) are seen to disfavour thermodynamically conformers 1b , 2b , 3b , and 4b , which can only be detected through cross-saturation transfer, while additional steric repulsions between Meax–C(1) and OHax–C(3) make conformer 8b of obtusol epimer so scarcely populated that it can not be detected. In agreement, with (+)- 9 and (+)- 10 , which have a trigonal C(2), two conformers can be directly observed by NMR. The kinetic barriers, which are seen to arise mainly from steric repulsions between Hax–C(14) and the axial H or halogen atoms at C(8) and C(10), are calculated and discussed with respect to well documented exocycliemethylidene-substituted cyclohexane(ene) systems. This helps to rationalize why in rogiolol acetate ((+)- 1 ) ring B is unusually inert towards Zn/Et2O/AcOH which causes bromohydrine-group elimination from ring A. 相似文献