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DFT computational study of the mechanism of allyl halides carbonylation catalyzed by nickel tetracarbonyl 总被引:1,自引:0,他引:1
Bottoni A Miscione GP Novoa JJ Prat-Resina X 《Journal of the American Chemical Society》2003,125(34):10412-10419
A theoretical investigation at the DFT(B3LYP) level on the carbonylation reaction of allyl bromide catalyzed by nickel tetra-carbonyl Ni(CO)(4) is discussed. The computational results show the following: (i) Three main steps characterize the catalytic cycle: (a) an oxidative addition step, (b) a carbonylation step, and (c) a reductive elimination step where the acyl product is obtained and the catalyst is regenerated. (ii) Both Ni(CO)(3) and Ni(CO)(4) complexes can behave as "active" catalytic species. (iii) The oxidative addition leads to the formation of either eta(3) or eta(1)-allyl nickel complexes, which are involved in a fast equilibrium. (iv) The carbonylation occurs much more easily on the eta(1) than on the eta(3) intermediates. 相似文献
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Pietro Aiena 《Rendiconti del Circolo Matematico di Palermo》1987,36(2):194-204
Nella prima parte di questo lavoro vengono studiate le relazioni che intercorrono tra il concetto di relativa regolarità in un'algebra non necessariamente unitaria ed alcuni ideali (radicale, zoccolo, prezoccolo) che intervengono nello sviluppo della teoria di Fredholm in algebre di Banach. Nella seconda parte del lavoro viene dimostrato che in certe algebre di BanachA complesse semiprime l'esistenza di un ideale relativamente regolare chiuso implica cheA è unitaria e di dimensione finita. 相似文献
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Pierfrancesco Bravo Calimero Ticozzi Beatrice Pelli Pietro Traldi 《Journal of heterocyclic chemistry》1988,25(2):685-688
The mass spectrometric behavior of 3-methyl-3-hydroxybenzoxocines has been studied in detail by means of linked scans and mass analyzed ion kinetic energy spectrometry. The structure of the molecular ion and the fragmentation processes are strictly related to the structure of the neutral moieties. The possible isomerization of 3-hydroxy-10-methoxy-3-methyl-3,4,5,6-tetrahydro-2H-[1]benzoxocine to 2-methyl-2-[3-(3′-methoxy-2′-hydroxy)phenyl]pentyloxirane and to 2-hydroxymethyl-9-methoxy-2-methyl-2,3,4,5-tetrahydro[1]benzoxepine is investigated. 相似文献
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Mario Giuffrida Pietro Maravigna Giorgio Montaudo Emo Chiellini 《Journal of polymer science. Part A, Polymer chemistry》1986,24(7):1643-1656
Some bipolyesters consisting of 1,2-propene glycol residue (P) and symmetric aromatic diacid residue constituted by two p-oxybenzoyl groups coupled by a terephthaloyl (HTH), phthaloyl (HOH) and isophthaloyl (HIH) group, and a nonsymmetric diacid residue constituted by a p-oxybenzoyl and a terephthaloyl group (HT), have been investigated by direct pyrolysis–mass spectrometry. The results show that intramolecular exchange reactions occurring at the pyrolysis stage cause a reorganization of the copolymer sequences. Sequential bipolyesters I–IV are ideal materials for the investigation of the extent of thermal reorganization induced in the bipolymer sequences by the pyrolytic process. 相似文献
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STO -3G minimal basis sets for first- and second-row transition metals have been formulated and applied to the calculation of equilibrium geometries for a variety of inorganic systems, metal carbonyls, and organometallic compounds. While the overall level of agreement with experiment is not as good as that previously noted for main-group compounds, most trends and many subtle features in geometries are reproduced. 相似文献
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Pietro Traldi Donata Favretto Silvia Catinella Olga Bortolini 《Journal of mass spectrometry : JMS》1993,28(7):745-751
The influence of different instrumental parameters on the mass displacements observed in an ion trap and a quadrupole mass filter was investigated. In ion trap measurements it was observed that isolated ions (obtained by both ‘apex’ and ‘two-step’ isolation methods) show the same mass displacements determined in the usual mass spectra; isobaric ions of different structure irradiated with supplementary a.c. fields are ejected at different a.c. voltages, and different cooling times do not affect the mass value. In the quadrupole mass filter, differences in mass were found among isobaric ions of different structure, although to a smaller extent than those observed in the ion trap. All the data obtained are in agreement with the hypothesis of ion–r.f. field interactions originating from the polarizability of the ion. 相似文献
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