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1.
Y. Lu Y. Morioka T. Matsui T. Tanaka H. Yoshii R. I. Hall K. Ito T. Hayaishi 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1995,35(2):125-129
The mass spectra of Xe
n
+
clusters (n=2–13) were recorded using a supersonic beam and an ion time-of-flight mass analyser. The yield of Xe
2
+
, Xe
3
+
and Xe
4
+
cluster ions was measured with a resolution of 0.1 Å (1 meV) in the 1024–1113 Å (11.1–12.1 eV) region. Autoionizing Rydberg series of Xe2 converging to theC
23/2u
state of Xe
2
+
were observed in the spectrum of Xe
2
+
. The photoionization yield of Xe
3
+
and Xe
4
+
ions each displayed similar broad features that contained no fine structure corresponding to vibrational states. The broad features were assigned to autoionizing Rydberg series by analogy with the dimer ion spectrum. 相似文献
2.
S. Suzuki Y. Kojima H. Shiromaru Y. Achiba T. Wakabayashi R. Tellgmann E.E.B. Campbell I.V. Herte 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,40(1):410-413
Photoionizationlfragmentation of endohedral fullerenes was investigated by use of laser-de sorption time-offlight (LD-TOF) mass spectroscopy. The velocity distribution of the parent ion (LaC 82 + ) was found to be bimodal, as has previously been shown for laser desorbed C 60 + . The 0 fragment ions have velocity distributions corresponding predominantly to the fast parent ion distribution. The LD-TOF mass spectra taken with a relatively low laser fluence were independent of the delay time of the extraction pulse, showing only a monotonically decreasing pattern of LaC 2n + (as n decreased). However, with higher laser fluence, it was shown that the mass distributions drastically changed from the monotonically decreasing pattern to that of C 2n + and LaC 2n + with magic numbers. Based on these findings, a plausible photoionization/fragmentation mechanism is presented and discussed. 相似文献
3.
A. G. Ryabenko V. E. Muradyan S. E. Esipov N. I. Cherepanova 《Russian Chemical Bulletin》2003,52(7):1516-1521
The transformation of the mass spectra of the laser-desorbed C60 and C70 samples with a successive increase in the laser power, resulting in an increase in the degree of excitation of C60 (C70) and in the number of the particles in the laser plume, was studied. Unusual metastable clusters (C60 + C2) and (C70 + C2) are formed even at a minimum laser power and begin to dissociate after 0.5 s following a short (3 ns) laser pulse. An increase in the laser power results in the appearance of peaks of metastable clusters C62 (C72) with the statistically normal lifetime without a delay of dissociation. A further increase in the laser power produces metastable clusters C60k–2n
and C70k–2n
(k = 2, 3) formed without a lag from the dimers and trimers of C60 (C70) by the ejection of a number of C2 required for the stabilization of the C2 molecules. The peak of C70 appears simultaneously with the appearance of the (C60)2–2n
peaks upon the laser desorption of pure C60. These findings provide evidence for the growth of the excited fullerene clusters by coalescence and subsequent stabilization due to the ejection of a small fragment rather than by the implantation of C2 into the fullerene framework. This mechanism of cluster growth should be taken into consideration in modeling fullerene formation in an electric arc reactor, because the clusters formed under these conditions have a substantial excess internal energy. 相似文献
4.
Paul F. Greenwood Michael G. Strachan Gary D. Willett Michael A. Wilson 《Journal of mass spectrometry : JMS》1990,25(7):353-362
The results from the laser-ablation Fourier transform mass spectrometric examination of a variety of polyaromatic hydrocarbons (PAHs), coals and other geochemically related materials are presented. Both molecular and quasi-molecular ions have been detected from different ring-sized PAHs. A relationship between the ease of sodium-adduct ion formation and the size of the aromatic array is observed. Nevertheless, suppression of [M + Na]+ ion formation in PAHs can be achieved by the addition of coal. In addition, distributions of low-mass positive- and negative-ion carbon clusters (Cn +, 14 ? n ? 27 and Cn, ?, 4 ? n ? 30), high-mass positive-ion carbon clusters (Cn+, 60 ? n ? 260) and low relative molecular mass organic compounds (< 600 daltons) have been observed from the coals. It appears that the ease of C formation may be used as an indicator of coal rank. Irradiance conditions also influence the observed distribution of high-mass positive-ion carbon clusters. Furthermore, distributions of the high-mass positive-ion carbon clusters at different irradiances supports an earlier proposal that their formation is kinetically controlled. 相似文献
5.
N. F. Gol'dshleger A. S. Astakhova A. S. Lobach G. N. Boiko N. N. Denisov V. A. Nadtochenko O. S. Roshchupkina Yu. M. Shul'ga 《Russian Chemical Bulletin》1996,45(10):2402-2404
Heating (100 °C, toluene) or photolysis (Nd3+ : YAG laser, = 532 mil, benzonitrile) of a mixture of ethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (Hantsch ester) (1) and fullerene C60 under anaerobic conditions results in the formation of fullerene hydrogenation products and ethyl 2,6-dimethylpyridine-3,5-dicarboxylate, which is the product of dehydrogenation of1, identified by IR spectroscopy and mass spectrometry. The triplet state of C60 is quenched by the Hantsch ester.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2531–2534, October, 1996. 相似文献
6.
Crystal structure of monodisperse non-ionic surfactants having the general formula C12H25O–(CH2–CH2–O)nH (C12En),n=7,9, 10, 15, 16 and ionic derivatives, C12H25–O–(CH2–CH2–O)n–CH2COONa (C12EnC),n=3,4,5,6,7,9, 12 has been investigated by13C-CP-MAS-NMR and x-ray diffraction. A structural model, in which aliphatic and polyether segments are segregated in bilayers stacking parallel to the elongation direction of the molecules, fits the experimental data for both series. The experimental values of the repeat distance along the stacking directiond(001) are linearly dependent onn and the slope is nearly equal to twice the repeat distance of7/2 helix conformation, which is typical for crystalline polyethyleneoxide. The values ofd(001) agree very well with the values expected for the C12 segment in a planar zig-zag conformation, which is tilted with respect to the polyerther segment (7/2 helix conformation) in such a way that both the aliphatic and the polyether regions adopt the mass density of the corresponding crystalline compound. Two additional phases have been detected for C12EnC. One of them is probably characterized by the planar zig-zag conformation of the polyether chain. The meader model, previously proposed in the literature for surfactants containing polyethylene oxide segments is inconsistent with the obtained experimental data. 相似文献
7.
T. Kasprzycka-Guttman H. Wilczura A. Myslinski 《Journal of Thermal Analysis and Calorimetry》1992,38(6):1357-1364
The excess heats of mixing for binary mixtures -picoline +n-alkanes (C6 to C10) at 298.15 K were measured and a comparison was made with the Prigogine-Flory-Patterson theory and the extended real associated solution method.
Zusammenfassung Die molaren Überschubenthalpien binärer Mischungen von -Picolin mit C6C10 n-Alkanen wurden bei 298.15 K im ganzen Zusammensetzungsbereich gemessen. Die gemessenen HE Werte wurden mit denen verglichen, die mit Hilfe von Prigogine-Flory-Patterson Theorie und nach der ERAS-Methode berechnet wurden.相似文献
8.
H. J. Busscher H. M. Uyen W. J. Postma A. van Silfhout J. Arends 《Colloid and polymer science》1987,265(8):711-714
Contact angles, measured with various liquids, have been employed to calculate the surface free energies of glass after adsorption of quaternary ammonium chlorides with a variable hydrocarbon chain length 8n16. The thickness of the adsorbed layers has been determined ellipsometrically. A clear relation is observed between the measured parameters and the hydrocarbon chain lengthn, if only the extremesn=8 andn=16 are considered. Surface free energies decrease from 138 erg.cm–2 for clean glass to 101 and 64 erg.cm–2 forn=8 andn=16, respectively, at the highest concentration tested (7.5 mM). The adsorbed layer thickness of C8 amounts to approximately 50 % of the thickness observed for C16. No clear relation between the measured parameters is observed for the intermediate hydrocarbon chain lengths, which presumably reflects the many configurations possible in these adsorbed layers. It is envisaged that adsorption of C8 as well as C16 is restricted to a monolayer, which is completed at approximately 2 mM. In the case of C8 electrostatic repulsion between the polar headgroups will inhibit further adsorption, whereas in the case of C16 the van der Waals attraction from the adsorbed layer and the glass will probably not be sufficient to stimulate further adsorption. 相似文献
9.
Stability of the C21H9(MCp)
n
(n = 1—3; M = Fe, Ru) complexes containing the C21H9 radical, a representative bowl-shaped precursor of C60 fullerene, was estimated. The carbon skeleton of the radical comprises three pentagonal faces (pent). DFT calculations of the C21H9 radical and its complexes were carried out with full geometry optimization and the PBE exchange-correlation potential. The energies of the M—pent bonds were found to increase with an increase in n, being only slightly lower than those in the hypothetical icosahedral 125—-C60(MCp)12 complexes and classical sandwich complexes M(Cp)2. The increased stability of the C21H9(MCp)
n
complexes was explained by greater involvement of the conjugated system of the polyhedral skeleton in the interaction. 相似文献
10.
Markin A. V. Smirnova N. N. Lebedev B. V. Davydov V. A. Kashevarova L. S. Rakhmanina A. V. 《Russian Chemical Bulletin》2003,52(4):862-868
The temperature dependences of the heat capacity C
p° = f(T) were studied in an adiabatic vacuum calorimeter for the orthorhombic, tetragonal, and rhombohedral polymeric C60 phases in the 7—340 K temperature interval with an error of 0.2%. Comparative analysis of C
p° of these phases formed by stacking of one-dimensional and two types of two-dimensional polyfullerenes C60, was performed, and their fractal dimensionalities D were determined for temperatures below 50 K. The thermodynamic functions of the crystalline polymeric C60 phases were calculated in the temperature region from O 0 to 340 K: C
p°(T), H°(T) — H°(0), S°(T) — S°(0), and G°(T) — H°(0). Assuming that S°(0) = 0, the standard entropies of formation f
S° of these phases from graphite at T = 298.15 K and standard pressure were calculated. In addition, the entropies of transformation of the initial face-centered cubic phase of fullerite C60 in the crystalline polymeric C60 phases and entropies of their interconversions under the same conditions were estimated. The thermodynamic characteristics of the polymeric C60 phases were reviewed. 相似文献
11.
Sunil Desai C. S. Feigerle John C. Miller 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(Z1):183-185
Supersonic jet expansions of mixtures of nitric oxide with either nitrous oxide or carbon dioxide have been investigated over a wide range of relative concentrations. Mixed molecular cluster ions of the form (NO)
m
+
(N2O)n and (NO)
m
+
(CO2)n are detected following non-resonant two-photon ionization. Over a wide range of intermediate concentrations, the cluster ion distributions (NO)
3
+
(N2O)n and (NO)
3
+
(CO2)n with n30 are significantly more intense than clusters containing other numbers of nitric oxide molecules. The extra abundance of these species is attributed to their especially stable structures and several possible forms are discussed. An intriguing possibility involves a stable cyclic nitric oxide trimer (or ion) when combined with nitrous oxide or carbon dioxide clusters. 相似文献
12.
B. M. Bulychev R. A. Lunin V. A. Kul’bachinskii R. V. Shpanchenko V. I. Privalov 《Russian Chemical Bulletin》2004,53(8):1686-1692
One- or two-step reactions of potassium and rubidium fullerides with composition Mk C60 (M = K, Rb; k = 3—6) and K6C60 + m K mixtures (m = 1, 3) with anhydrous salts MCl3 (M = La, Pr, Nd, Sm, Gd, Tb, Yb, Lu, Y, Sc) and YbI2 in a toluene—THF medium afforded heterometallic fullerides M3–nMnC60 (n = 1—3). Among these compounds, substituted fullerides with composition M2MC60 (M = Yb, Lu, Sc) display superconducting properties with critical temperatures of 14—20 K.Published in Russian in Izvestiya Akademii Nauk.
Seriya Khimicheskaya, No. 8, pp. 1623–1628, August, 2004. 相似文献
13.
H. G. M. Edwards V. Fawcett M. T. Lung 《Journal of inclusion phenomena and macrocyclic chemistry》1991,11(3):267-279
Force constants were determined for the C8, C10, C12 and C14 series ofn-alkanes C
n
H2n + 2 using an approximate SVFF calculation and observed LAM = 1 wave numbers. In this calculation the hydrogen atoms were neglected and only the carbon backbone chain and terminal atoms were considered; this was valid since only low-frequency vibrations were under consideration. Using force constant transfer, the wavenumbers of the LAM = 1 accordion modes for the analogous -Cn H2n + 1 X and ,-Cn H2nX2 species, where X = C1, Br or I were calculated. For -chloroalkanes and ,-dichloroalkanes, them = 1 accordion modes are calculated to be in the 220–130 cm–1 and 200–120 cm–1 regions, respectively. For the bromo- and iodo-analogues them = 1 accordion modes are calculated to be in the 200–100 cm–1, 150–90 cm–1 and in the 170–100, 135–80 cm–1 regions, respectively. 相似文献
14.
Formation,properties, and thermal decomposition of bisarene chromium(i) and molybdenum(i) fullerides
G. A. Domrachev Yu. A. Shevelev V. K. Cherkasov G. V. Markin G. K. Fukin S. Ya. Khorshev B. S. Kaverin V. L. Karnatchevich 《Russian Chemical Bulletin》2004,53(9):2056-2059
Fullerides [(6-Ph2)2Cr]+[C60]·–, [(6-C10H12)2Cr]+[C60]·– (C10H12 is tetralin), and [(6-PhCH3)2Mo]+[C60]·– were synthesized. The molecular structure of [(6-Ph2)2Cr]+[C60]·– was established. In this compound at 100 K, radical anions C60
–· are linked by an ordinary bond to form dimers, whereas at 293 K they are disordered and do not form dimers. The [(6-tetralin)2Cr]+[C60]·– fulleride is stable in vacuo (10–2 Torr) below 429 K, and [(6-toluene)2Mo]+[C60]·– is stable below 581 K.Based on the materials presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry (Moscow, May 30–June 4, 2004) dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1973–1976, September, 2004. 相似文献
15.
Reaction of (RNPF3)2 compounds (R=CH3, C2H5,n-C3H7,n-C4H9,i-C4H9) withN-trimethylsilyl-methylamine leads to nucleophilic substitution of one or two fluorine atoms by the methylamino group, depending on the molar amounts of the reactants. In the case ofR=CH3, two by-products are formed: in the first step a compound with coordination numbers IV, V and VI for the three phosphorus atoms in C5H17F7N5P3 and in the second step a monospiroflourodiaza-5, 5-diphosphetidine.
9. Mitteilung:Utvary, K., Kubjacek, M., Varmuza, K. Z. anorg. allg. Chem.458, 281 (1979). 相似文献
16.
N. Adolph T. Heinzel M. Weidemüller H. Figger 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1992,24(1):15-23
Rare gas hydride molecules and triatomic hydrogen molecules were produced in a Cossart-type plasma beam Penning tube specially designed for laser spectroscopic work. A cw dye laser was used to stimulate transitions from theB
2
rovibrational levels to theA
2+ levels of argonhydride (40ArH) and argondeuteride (40ArD). The transitions were detected by measuring the decrease of the spontaneous emission from the upper levels, which clearly shows the expected population inversion between the two participating electronic states. With this first laserspectroscopic work on argonhydride and argon deuteride, the classification of the lines of theB
2
A
2+ band as given by Johns 1970 could be checked and was found to be consistent*. Furthermore theQ branches of these bands for ArH and ArD could be completely resolved into their single lines and their wavelengths were measured. The latter allowed the difference between the rotational constants of theA andB electronic states to be directly determined. The method was also applied to triatomic hydrogen. D3. It should be useful for classifying more complicated bands of ArH and of KrH and XeH, which can also be produced in this tube.In later theoretical work theB
2
state was called 22
state [13] andE
2
state [12], respectively 相似文献
17.
A. V. Bazhenov M. Yu. Maksimuk T. N. Fursova A. P. Moravsky V. A. Nadtochenko 《Russian Chemical Bulletin》1996,45(6):1389-1393
Single Crystals of C60/TMPD and C60/TPA have been grown from a chlorobenzene solution. Optical transmission spectra of single crystals of fullerene complexes withN,N,N,N-tetramethyl-p-phenylenediamine (TMPD) and triphenylamine (TPA) are studied in the spectral range from 600 to 16000 cm–1. Splitting of the intramolecular vibration of C60 is observed at 1428 cm–1, which is likely caused by freezing of the rotation of the C60 molecules due to their interaction with amines. Single crystals of C60/TMPD differ from those of C60/TPA by a decrease in the vibration frequency at 1428 cm–1, vibrations of the C-C bonds of the TMPD molecule, and the redistribution of the forces of the oscillators of the vibrations of the C-N bonds. These peculiarities are interpreted to be the result of partial electron transfer from TMPD to C60 in the C60/TMPD single crystals. The electron transfer in the C60/TPA system is less pronounced.Translated fromIzvestiya akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1459–1464, June, 1996 相似文献
18.
Rapid coalescence was studied on liquid paraffin emulsion stabilized with a series of poly(oxyethylene) dodecyl ethers [C12H25 (EO),n=1, 2, 3, 4, 5, 6, 7, 8] and of poly(oxyethylene) nonylphenyl ethers [C9H19(EO)
n
,n=2, 4, 5, 6, 12]. The turbidity of emulsion was measured as a function of the solution pHs at constant ionic strength of 0.1 mol dm–3.As a result, it was found that the emulsions (which were formed with C12H25(EO)
n
surfactants having less than four oxyethylene groups, or with C9H19 (EO)
n
surfactants having less than six oxyethylene groups) brought about rapid coalescence in the bulk pH between 2.03.5, which corresponded to the zero point of charges for the emulsions of the present systems. According to the Tadros treatment for emulsion flocculation, the total flocculation potennual was estimated as a function of the distance relative to the number of oxyethelene groups in the surfactants. The critical coalescence energy was obtained as –343 ×10–19 J for the C12H25(EO)
n
surfactants and –2.14×10–19) J for the C9H19 (EO)
n
surfactants. Furthermore, the formation of a hole for coalescence was estimated under the simple assumption that the coalescence was caused only by the energy dissipation. 相似文献
19.
V. A. Nadtochenko N. N. Denisov I. V. Rubtsov A. P. Moravsky 《Russian Chemical Bulletin》1996,45(5):1091-1098
The kinetics of charge recombination in radical ion pairs C70
–/Am+ (Am isN, N, NN-tetramethyl-p-phenylenediamine,p-methoxy-N,N-dimethylaniline,p-methyl-N,N-di-methylaniline,N,N-diethylaniline,N,N-dimethylaniline, and triphenylamine) in chlorobenzene was studied by the picosecond laser photolysis technique. The radical ion states are the products of excitation of charge-transfer complexes between C70 and amines and are also formed by quenching of the singlet excited state of C70 by the amine. The rate constant of electron transfer in the radical ion pair decreases as the free Gibbs energy (G) of the reaction increases and reflects the Marcus-inverted region of the dependence of the rate constant on G. The C70/Am and C60/Am systems are compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1151–1158, May, 1996. 相似文献
20.
V. V. Bashilov P. V. Petrovskii V. L. Sokolov F. M. Dotgushin A. L. Yanovsky Yu. T. Struchkov 《Russian Chemical Bulletin》1996,45(5):1207-1213
A novel optically active exo-metallofullerene derivative, 2-C60Pt[(+)-DIOP] (1) (DIOP is 2,3-o,o'-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphinobutane)), is formed as a result of the cleavage of the chelate metallocycle in Pt[(+)-DIOP]2 and the substitution of the bidentate (+)-DIOP ligand with C60. Cluster 1 was also obtained by replacement of the phosphine ligands in 2-C60Pt(PPh3)2 by (+)-DIOP. Compound 1 was identified by its electronic absorption spectra,31P NMR spectra, and the elemental analysis data. A singlecrystal X-ray study of the 1 cyclooctene solvate, 2-C60Pt[(+)-DIOP] C8H14 was performed. Packing of the fullerene cores in a crystal of 1 · C8H 14 corresponds to the diamond structure subjected to the significant orthorhombic distortions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1268–1274, May, 1996. 相似文献