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91.
Christiane Santelli-Rouvier Maurice Santelli Jean-Pierre Zahra 《Tetrahedron letters》1985,26(9):1213-1216
(+)-2-carene heated neat with iron pentacarbonyl leads to α-phellandrene-Fe(CO)3 complex ( ~15 % ), p. cymene ( ~15 % ), (-)-(1S)-3,8,8-trimethylbicyclo (4.1.1) oct-3-ene-7-one ( ~50 % ) and (+)-(1S,7S)-3,8,8-trimethylbicyclo (4.1.1.) oct-3-ene-7-ol ( ~20 % ). 相似文献
92.
De Zorzi R Dubessy B Mulatier JC Geremia S Randaccio L Dutasta JP 《The Journal of organic chemistry》2007,72(12):4528-4531
Four tetraphosphorylated TiiiiPO cavitands 1 encapsulate the pyridinium heads of a tetrakis(N-methylpyridinium)porphyrin iodide to form a 4:1:4 (host)4/guest4+/4I- complex. The single-crystal X-ray diffraction analysis shows the arrangement of the four cavities bound to the CH3N+ groups of the porphyrin moiety and the four iodide anions nested between the phenethyl substituents of the hosts. 1H NMR investigations show that the structure is preserved in chloroform solution and underscore the effect of the counteranions. 相似文献
93.
Roger Azria Yvonnick Le Coat Jean-Pierre Ziesel Jean-Pierre Guillotin Brahim Mharzi Michel Tronc 《Chemical physics letters》1994,220(6):417-422
Absolute kinetic energy distributions and yields associated with ground state 3P and excited state 1D oxygen atoms have been obtained for O− anion electron stimulated desorption from condensed O2 in the electron energy range 6–15 eV. The observed yields are understood as resulting essentially from dissociative electron attachment reactions via the two lowest 2Σ+g O−2 resonance states through adiabatic and non-adiabatic transitions to the limits O−(2P) + O(3P) and O−(2P) + O(1D). The kinetic energy distributions show the prominent role of electron multiple collision processes and post-dissociation interactions of the O− anions in the condensed phase. 相似文献
94.
Kanibolotsky A Roquet S Cariou M Leriche P Turrin CO de Bettignies R Caminade AM Majoral JP Khodorkovsky V Gorgues A 《Organic letters》2004,6(13):2109-2112
[structure: see text] In four new dendrimers terminated by 12 electroactive tetrathiafulvalenyl substituents, the tridimensional character of the inter- and intradendrimeric charge and electron transfer, and hence of the electroconductivity, is evidenced by examination of the electronic spectra of their corresponding neutral state and cation radical, dication, and mixed-valence salts, including a closed-shell anion. 相似文献
95.
96.
The reaction of mercuric salts HgY2 or organic mercuric compounds RHHgX with long chain perfluorinated Grignard reagents RFMgBr leads to a series of new perfluoroalkyl mercury derivatives with the general formula RFHgZ (RF=C4F9, C6F13, C8F17 ; Z=RF,RH,Y with Y = I,Br,Cl, NO3,OCOCH3,OCOCF3).The synthesis of these organomercuric compounds is described, and their spectroscopic properties are reported. 相似文献
97.
Malassene R Vanquelef E Toupet L Hurvois JP Moinet C 《Organic & biomolecular chemistry》2003,1(3):547-551
The anodic cyanation of methanolic solutions of the 2-alkyl-N-phenylpiperidines 6b-d was performed in a flow cell equipped with a graphite felt anode. The reaction led to the formation of the 2-cyano-6-alkyl-N-phenylpiperidines 2b-d and proceeded with a high degree of regioselectivity. The 1H NMR spectra of the aminonitriles 2b-d showed an epimeric mixture at C-6. The major isomer has a trans configuration in which the cyano group is axial and the alkyl substituent is equatorial. Conversely, electrochemical oxidation of the 4-methyl-6-pentyl-N-phenylpiperidine 6e afforded the trisubstituted aminonitrile 2e as a single diastereomer (> 98% de). The 4-cyanobutyl side chain was incorporated in a two-step procedure to yield dinitrile 4e. This latter compound was directly converted into spiropiperidine 5e by using the Thorpe-Ziegler annulation procedure. The overall sequence (4 steps, 43%) allows the construction of the basic carbon framework of perhydrohistrionicotoxin. 相似文献
98.
The selection and quality of hops is a major determinant in beer flavour. Brewers acknowledge that distinctive characteristics of different hop varieties can be traced to the composition of their essential oils. The difficulty in characterising complex mixtures such as hop oil using 1-D chromatography is that many compounds co-elute. With the introduction of comprehensive multidimensional capillary gas chromatography (GC x GC), there is a tremendous improvement in the separation power or peak capacity. Recent work using GC x GC with flame ionisation detection has suggested that there may be over 1,000 compounds in hop oil. This work describes the use of GC x GC combined with TOFMS detection (Leco Pegasus 4D instrument) to analyse Target hop oil. The TOFMS spectral acquisition rate of 60 Hz provided sufficient spectra per peak (2-D peak base width of 0.1-0.2 s) for identification (119 components were identified with 45 previously unreported compounds). When analysing results, an advantage of GC x GC coupled to TOFMS is that 2-D chromatograms can be viewed for individual masses that are characteristic of particular functional groups. This allows the analyst to view the various homologous series of compounds although in certain cases coelution may still be present as shown by the esters with mass 75. 相似文献
99.
Alexander I. Popov Alfred J. Smetana Jean-Pierre Kintzinger Thi Thanh-Tam Nguyêen 《Helvetica chimica acta》1980,63(3):668-673
Complexation between crown ethers 12C4, 15C5, 18C6 and cryptand 222, and alkali cations Li+, Na+, K+ in various solvents were studied by 17O-NMR. spectroscopy. Small diamagnetic shifts arising from the cation electric field are observed. They increase according to the sequence K+ < Na+ < Li+. 17O-linewidth are discussed and compared to the 13C relaxation times. Linewidth modification results mainly from modifications of the effective correlation time. In general, for crown ethers, considerable line broadening occurs when the cation fits well into the cavity but line narrowing occurs when the cation is much smaller than the cavity. 相似文献
100.
Hans-Ulrich Gonzenbach Inga-Mai Tegmo-Larsson Jean-Pierre Grosclaude Kurt Schaffner 《Helvetica chimica acta》1977,60(3):1091-1123
2-Cyclopentenyl and 3-phenyl-2-cyclopentenyl methyl ketones (15–18, 30, 31) undergo a 1,3-acetyl shift on direct irradiation, and the oxa-di-π-methane rearrangement to photochemically non-interconverting endo and exo bicyclo-[2.1.0]pentyl methyl ketones on triplet sensitization. Exceptions include the 2-methyl-3-phenyl-2-cyclopentenyl methyl ketone 32 and the 1-phenyl-2-cyclo-pentenyl methyl ketone 44 which are unreactive on direct irradiation and on triplet sensitization, respectively, and the 2-phenyl-2-cyclopentenyl methyl ketones 42 and 43 which do not react under either condition. The reactive triplet of the 3-phenyl-2-cyclopentenyl methyl ketone 30 has been identified as the localized styrene π,π*-state of ET=59 kcal/mol by comparison of its phosphorescence at 77K in rigid glasses with that of 1-phenyl-cyclopentene, and by the independence of the quantum yield on sensitizer energy in the range of 61–74 kcal/mol. 相似文献