研究者詳細 - 中嶋　敦

論文 - 中嶋　敦

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Electronic shell structure of indium-sodium (In_nNa_m) bimetallic clusters examined by their ionization potentials and mass distributions

A. Nakajima, K. Hoshino, T. Sugioka, T. Naganuma, T. Taguwa, Y. Yamada, K. Watanabe, K. Kaya

Journal of Physical Chemistry （American Chemical Society） 97 （ 1 ） 86 - 90 1993年01月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00223654

Indium-sodium (InnNam) bimetallic clusters were produced by two independent laser vaporization methods. Ionization potentials (IPs) of the InnNam clusters were measured up to m = 2 using a tunable ultraviolet laser combined with a time-of-flight (TOF) mass spectrometer. At small sizes (n = 3-15), the ionization potentials decrease by 0.1-0.8 eV with the addition of Na atom(s), whereas the IPs of larger Inn (15 ≤ n ≤ 27) clusters do not decrease with Na addition. Moreover, IPs of In7Na1 and In13Na1 clusters are higher than those of In7 and In13, and the IP increments can be explained by electronic shell closings of the 1p (8e) and 2p shell (40 e), where In atoms in the clusters are monovalent and trivalent, respectively. The electronic shell structure was also examined by a magic number in mass distributions of InnNam- cluster anions; the In12Na3- cluster can be observed as magic numbers, corresponding to the 2p shell closing. In contrast, no electronic shell structure is observed in pure Inn clusters around n = 13. These results indicate that Na atom addition can induce s/p hybridization in the Inn clusters. We also present mass distributions of aluminum-sodium cluster anions, AlnNam-, whose feature can be understood by the electronic shell model. © 1993 American Chemical Society.

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Electronic spectra of p-dicyanobenzene (p-DCNB), p-DCNB-H₂O complex, and p-DCNB dimer in a supersonic jet

K. Fujita, T. Fujiwara, K. Matsunaga, F. Ono, A. Nakajima, H. Watanabe, T. Koguchi, I. Suzuka, H. Matsuzawa, S. Iwata, K. Kaya

Journal of Physical Chemistry （American Chemical Society） 96 （ 26 ） 10693 - 10697 1992年12月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 00223654

S1-S0 electronic spectra of jet-cooled p-dicyanobenzene (p-DCNB), its H2O complex, and the dimer ((p-DCNB)2) were recorded using laser-induced fluorescence and two-color multiphoton ionization methods. Several vibrational bands in S1 of the monomer were assigned to the corresponding vibrational modes in the ground S0 state. Geometric structures of p-DCNB-H2O and (p-DCNB)2 were determined by the analyses of rotational envelopes of the vibronic bands of these complexes. © 1992 American Chemical Society.

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Ionization potentials of cobalt-sodium bimetallic clusters (Co_nNa_m)

K. Hoshino, T. Naganuma, Y. Yamada, K. Watanabe, A. Nakajima, K. Kaya

The Journal of Chemical Physics （American Institute of Physics） 97 （ 5 ） 3803 - 3807 1992年09月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 00219606

Cobalt-sodium bimetallic clusters (ConNam, n = 3-48) were produced by a two independent laser-vaporization method. Ionization potentials of the ConNam clusters were measured up to m = 3 using a tunable ultraviolet laser combined with a time-of-flight (TOF) mass spectrometer. In general, the ionization potentials decrease monotonically with the number of sodium atoms, and the ionization potentials of Co nNam+1 decrease by 0.2-0.8 eV compared to those of the corresponding ConNam cluster. However, the amount of IP decrement by the Na doping is relatively large at n ≤ 17 whereas it is small and constant at n ≥ 18. This feature can be explained by a geometric rearrangement; at small n, the Na doping induces a large geometric rearrangement of the cluster, but at large n, the geometric change is small. Reactivity of ConNam cluster toward H2 was also measured and the effect of the Na doping was studied. The reactivity also suggests the geometric change induced by the Na doping. Moreover, we examined the anticorrelation between IP and reactivity of the ConNam clusters, and no anticorrelation between them could be revealed. © 1992 American Institute of Physics.

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Magic Numbers of Bimetallic Cluster Ions Consisted of Group-Ⅲ Metals: the Icosahedron Structure of 13 Atoms Clusters

A. Nakajima, T. Sugioka, T, Kishi, K. Kaya

Physics and Chemistry of Finite Systems: From Clusters to Crystals （Kluwer Academic Publishers） 1 99 - 104 1992年09月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り

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Electronic Structure and Reactivity of Bimetallic Clusters Containing Sodium Atoms

K. Kaya, A. Nakajima, T. Naganuma, K. Hoshino

Physics and Chemistry of Finite Systems: From Clusters to Crystals （Kluwer Academic Publishers） 1 229 - 234 1992年09月

研究論文（学術雑誌）, 共著, 査読有り

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Polarized laser induced fluorescence of BaO (X ¹Σ⁺) produced in a crossed-beam reaction of Ba+SO₂

A. Nakajima, T. Munakata, T. Nagata, T. Kondow, T. Kasuya

The Journal of Chemical Physics （American Institute of Physics） 97 （ 2 ） 991 - 996 1992年07月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00219606

Rotational alignment of the product BaO in the crossed-beam reaction Ba+SO2 → BaO+SO was studied as a function of collision energy. The collision energy was varied from 3.0 to 8.0 kcal/mol by changing the stagnation condition of the supersonic SO2 beam. The rotational alignment was probed by means of the polarized laser-induced fluorescence (PLIF) of the product. The distribution of the rotational vector was isotropic at the collision energy of 3.0 kcal/mol, but anisotropic at a higher collision energy, with the most probable alignment being perpendicular to the relative velocity vector. These results indicate that the reaction proceeds via a long-lived complex at a low collision energy, whereas at a higher collision energy, the lifetime of the complex is short enough to couple the rotational angular momentum to the total angular momentum. © 1992 American Institute of Physics.

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Mass distributions of negative cluster ions of sodium oxide

A. Nakajima,T. Sugioka, K. Hoshino, K. Kaya

Chemical Physics Letters （Elsevier Science BV） 189 （ 4-5 ） 455 - 459 1992年02月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 0009-2614

Negative cluster ions of sodium oxide, NanO−m (m = 1 and 2), were generated by laser vaporization of a sodium rod, and their mass distribution was measured. In the mass spectra, a number of intense peaks compared to neighbors were observed; in NanO−1, the “magic numbers” were observed at n = 9, 21, 27, 35, 41, and 59, and in NanO−2, they were observed at n = 11, 17, 23, 29, 37, 43, and 61. Compared with the magic numbers predicted by the jellium shell model, two and four sodium atoms are increased for the magic numbers by adding one and two oxygen atom(s), respectively. Therefore, it is concluded that (1) no valence electrons of oxygen atoms contribute to form the electronic shells of clusters, and that (2) two sodium atoms in the NanO−m clusters are bound by one oxygen atom, forming an Na2O unit as a spectator. © 1992, All rights reserved.

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Electronic and geometric structures of aluminum-boron negative cluster ions (Al_nB_m^-)

A. Nakajima, T. Kishi, T. Sugioka, K. Kaya

Chemical Physics Letters （Elsevier Science BV） 187 （ 3 ） 239 - 244 1991年12月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00092614

Aluminum-boron negative cluster ions (AlnB-m, n=5-30, m=1-3) were generated by two independent laser-vaporization sources. The mass distribution of AlnB-2 exhibits one peak at n=12 and one step between n=22 and 23 as magic numbers, whereas that of AlnB-2 exhibits only one step between n=21 and 22. The loss of the magic number of Al11B-2 can be explained by the geometric structures: Al12B-1 is stabilized by both an electronic shell closing of the 2p shell and a close-packing structure of icosahedron. In contrast, Al11B-2 can satisfy the electronic shell closing by cannot take the stable geometric structure because the diameters of Al and B atoms differ largely. The structure of Al12B-1 can be an icosahedron with a B atom located at the center. © 1991.

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Ionization potentials of aluminum-sodium bimetallic clusters (Al_nNa_m)

A. Nakajima, K. Hoshino, T. Naganuma, Y. Sone, K. Kaya

The Journal of Chemical Physics （American Institute of Physics） 95 （ 10 ） 7061 - 7066 1991年11月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00219606

Aluminum-sodium bimetallic clusters (AlnNam, n = 2-26) were produced by two independent laser vaporization methods. To investigate the electronic structures, ionization potentials of the Al nNam clusters were measured up to m = 3 using a tunable ultraviolet laser combined with time-of-flight (TOF) mass spectrometer. In general, the ionization potentials monotonically decrease with the number of sodium atoms, and the ionization potentials of AlnNa1 generally decrease by 0.2-0.6 eV compared to those of the corresponding Al n cluster. In contrast, the ionization potentials of Al 13Na1 and Al23Na1 are higher than (or equal to) those of Al13 and Al23. The anomalous change in the ionization potentials of Al13Na1 and Al 23Na1 can be explained by the electronic shell model: By the addition of one sodium atom to the bare aluminum clusters, the total number of their valence electrons strictly satisfies the shell closing of 2p and 3s shells, respectively, and therefore, the clusters can be stabilized electronically. © 1991 American Institute of Physics.

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Structure and reactivity of bimetallic Co_nV_m⁺ cluster ions

A. Nakajima, T. Kishi, T. Sugioka, Y. Sone, K. Kaya

Journal of Physical Chemistry （American Chemical Society） 95 （ 18 ） 6833 - 6835 1991年09月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00223654

The reaction of bimetallic ConVm+ cluster ions, generated by laser vaporization, toward hydrogen was investigated by using a fast-flow reactor. Compared with pure Con+ cluster ions, the reactivity of Con-1V+ cluster ions exhibits a drastic decrease at n ≥ 13 similar to that of neutral ConVm clusters. The result can be explained in terms of their geometrical structure; at n ≥ 13, the V atom is located at the center of the cluster and is surrounded by Co atoms. © 1991 American Chemical Society.

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Production of bimetallic clusters containing manganese atoms by laser-vaporization method

Y. Sone, K. Hoshino, T. Naganuma, A. Nakajima, K. Kaya

Journal of Physical Chemistry （American Chemical Society） 95 （ 18 ） 6830 - 6832 1991年09月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 0022-3654

Bimetallic clusters containing manganese atoms were generated by applying a laser-vaporization method. The bimetallic clusters composed of Ta and Mn, TanMnm, were produced and could be mixed in any ratio, whereas those composed of Co and Mn, ConMnm, could only be produced with more than four cobalt atoms; Co4 plays an important role in the production of ConMnm clusters. The difference of mass distribution between TanMnm and ConMnm can be qualitatively explained by an analogy of their phase diagrams in the bulk. © 1991 American Chemical Society.

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Reactivity of positively charged cobalt cluster ions with CH₄, N₂, H₂, C₂H₄, and C₂H₂

A. Nakajima, T. Kishi, Y. Sone, S. Nonose, K. Kaya

Zeitschrift für Physik D Atoms, Molecules and Clusters （Springer Nature） 19 （ 4 ） 385 - 387 1991年03月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 0178-7683

<p>Reactivity of positively charged cobalt cluster ions (Co_n⁺, n=2-22), produce by laser vaporization, with various gas samples (CH₄, N₂, H₂, C₂H₄, and C₂H₂) were systematically investigated by using a fast-flow reactor. The reactivity of Co_n⁺ with the various gas samples is qualitatively consistent with the adsorption rate of the gas to cobalt metal surfaces. Co_n⁺ highly reacts with C₂H₂ as characterized by the adsorption rate to metal surfaces, and it indicates no size dependence. In contrast, the reactions of Co_n⁺ with the other gas samples indicate a similar cluster size dependence; at n=4, 5, and 10-15, Co_n⁺ highly reacts. The difference can be explained by the amount of the activation energy for chemisorption reaction. Compared with neutral cobalt clusters, the size dependence is almost similar except for Co₄⁺ and Co₅⁺. The reactivity enhancement of Co₄⁺ and Co₅⁺ indicates that the cobalt cluster ions are presumed to have an active site for chemisorption at n=4 and 5, induced by the influence of positive charge.</p>

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Mass distributions of aluminum negative cluster ions and their binary cluster ions mixed with a carbon atom

A. Nakajima, T. Kishi, T. Sugioka, Y. Sone, K. Kaya

Chemical Physics Letters （Elsevier Science BV） 177 （ 3 ） 297 - 300 1991年02月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 0009-2614

The mass distributions of aluminum negative cluster ions and their binary cluster ions mixed with a carbon atom, generated by laser vaporization, were measured. In the range from n=5 to 70, the mass distribution of pure aluminum negative cluster ions, Al-n, exhibits one peak at n = 13 and one step between n=23 and 24. The mass distribution of the series of AlnC-, however, exhibits one peak at n=7 and one step between n=24 and 25. The absence of a peak in the series of AlnC- around n=13 can be explained by the electronic structure in relation to the electronic shell model, and both the peak and the step in the mass distribution of AlnC- clusters can be explained by their geometric structure. © 1991.

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Photodissociation dynamics of NH₃, NH₂D, NHD₂, and ND₃: Rovibronic absorption analysis of the Ã-X̃ transition

A. Nakajima, K. Fuke, K. Tsukamoto, Y. Yoshida, K. Kaya

Journal of Physical Chemistry （American Chemical Society） 95 （ 2 ） 571 - 574 1991年01月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00223654

The photodissociation dynamics of Ã state ammonia molecules has been further investigated for deuterium-substituted derivatives NH2D, NHD2, and ND3 measuring the homogeneous line widths on action spectra. The line widths of the 201 vibronic band were determined to be 19, 12, and 1.3 cm-1 fwhm for NH2D, NHD2, and ND3, respectively. In consideration of our previously reported value of 26 cm-1 for NH3, the spectral line width decreases in proportion to the number of D atoms. This result shows that the dissociation rate in the Ã state is additive as for the number of H atoms, and it is explained by the fact that the zero-point energies on the potential surface of Ã state are equally shifted among deuterium-substituted ammonias. © 1991 American Chemical Society.

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Electronic spectrum of jet-cooled cyanocyclopentadienyl radical

T. Ishida, H. Abe, A. Nakajima, K. Kaya

Chemical Physics Letters （Elsevier Science BV） 170 （ 5-6 ） 425 - 429 1990年07月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 0009-2614

The D1-D0 electronic spectrum of jet-cooled cyanocyclopentadienyl (C5H4CN) radical, produced by excimer laser photolysis of 1,3-cyclopentadiene-1-carbonitrile (C5H5CN), was measured by laser-induced fluorescence (LIF). The LIF spectrum was identical to that of radicals produced by photolysis of phenyl isocyanate and o-chloroaniline, which had been assigned to phenyl nitrene. This result shows that the nascent radical product in the photolysis of o-chloroaniline and phenyl isocyanate is isomerized to C5H5CN and the final product of C5H4CN radical is derived via the second photolysis. The rotational contour of the 0-0 band of the C54CN radical, at 27143 cm-1 (368.3 nm), is also presented. The electronic transition is A-type and π electron transition, and the symmetry of both the ground and excited electronic state is 2B1 (of the C2v point group). © 1990.

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Rotational distributions of CO₂⁺ (X̃ ²Π_g) produced by electron-impact ionization of supercooled CO₂

A. Nakajima, T. Nagata, T. Kondow, K. Kuchitsu

Chemical Physics Letters （ELSEVIER SCIENCE BV） 151 （ 6 ） 511 - 515 1988年10月

研究論文（学術雑誌）, 共著, 筆頭著者, 査読有り, ISSN 00092614

Laser-induced fluorescence of CO2+ (X̃ 2Πg) produced by electron impact on CO2 in a supersonic beam was measured. An analysis of the CO2+ (Ã-X̃) spectra has revealed that the rotational distribution of CO2+ is essentially Boltzmann and that the effective rotational temperature increases uniformly with decreasing impact energy, 26± 1 K at 300 eV and 31 ± 1 K at 45 eV. This trend of rotational excitation, which is similar to that observed in the N2 + e system, is interpreted in terms of the rotational transitions in electron-impact ionization. © 1988.

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Nascent rotational distributions of N₂⁺(X ²Σ_g⁺) produced by electron-impact ionization of N₂ in a supersonic beam

T. Nagata, A. Nakajima, T. Kondow, K. Kuchitsu

The Journal of Chemical Physics （American Institute of Physics） 87 （ 11 ） 6507 - 6512 1987年12月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 00219606

Laser-induced fluorescence from nascent N2+(X 2Σg+) ions produced by electron impact on a N2 supersonic beam was observed. An analysis of the B 2Σu+-X 2Σ g+ (0,0) band shows that the rotational state distributions cannot be represented by a single Boltzmann function, higher N″ levels being overpopulated. Experimental and analytical efforts were made to minimize the influence of cascading and relaxation on the rotational distributions. The rotational energy of N2+ (X) thus estimated increases with decreasing electron energy from 2.26±0.16 meV at 300 eV to 4.24±0.27 meV at 25 eV. This trend is explained qualitatively in terms of angular momentum transfer through multipole electron-molecule interactions. © 1987 American Institute of Physics.

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Polarized laser induced fluorescence of N₂⁺（X²Σ_g⁺) produced in the electron impact ionization of N₂

T. Nagata, A. Nakajima, T. Kondow, K. Kuchitsu

Chemistry Letters （Chemical Society of Japan） 16 （ 10 ） 1911 - 1914 1987年03月

研究論文（学術雑誌）, 共著, 査読有り, ISSN 0366-7022

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中嶋 敦

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中嶋　敦

論文 - 中嶋　敦