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951.
952.
Y. Yamada K. Katsumata Y. Ono K. Yamaguchi 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(3):419-423
Reactions of laser-evaporated iron atoms with ethylene molecules were investigated. The reaction products were trapped in a low-temperature matrix observed by Mössbauer and infrared spectroscopies. Fe(C2H4) was produced at low ethylene concentration, and Fe(C2H4)2 was obtained as the major product at higher ethylene concentration. The assignments were confirmed through molecular orbital calculations. 相似文献
953.
The permutation-inversion group developed by Longuet-Higgins is extended to a classification of the vibronic, torsional, and rotational wavefunctions of a nonrigid X2Y2 molecule by introducing a symmetry operation , which rotates the top half of the molecule by 2π and, accordingly, the molecule-fixed x axis by π. Since the energy levels of linear (D∞h) and bent (C2h, C2h, and C2) forms of X2Y2 are classified according to a set of common symmetry operations of this extended permutation-inversion group, their energy levels can be correlated, including those of nonrigid forms such as a quasilinear system or a free internal rotor. Nuclear spin weights and selection rules are derived. 相似文献
954.
955.
The representative (E)-1-alkenyldisiamylboranes and (E)-1-alkenyl-1,3,2-benzodioxaboroles readily obtainable hydroboration of 1-alkynes react with 1-alkenyl halides or 1-alkynyl halides in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium and base to give corresponding conjugated (E)-dienes or (E)-enynes with high regio- and stereospecificity in good yields, respectively. 相似文献
956.
Shuichi Iwadare Yoshikazu Shizuri Kiyoyuki Yamada Yoshimasa Hirata 《Tetrahedron letters》1974,15(13):1177-1178
Synthesis of trichotomine, a blue pigment obtained from thunb. 相似文献
957.
Yasuji Yamada Sukeji Suzuki Kazuo Iguchi Hiroyuki Kikuchi Haruo Horiai Fumio Shibayama 《Tetrahedron letters》1980,21(40):3911-3914
The relative and absolute stereochemistry of two 13-membered carbocyclic cembranolides was determined as shown in and on the basis of NMR spectral evidence. 相似文献
958.
959.
960.
We predict and observe a new class of echoes of atomic sublevel coherences induced by two impact excitations with resonant light pulses which may be either coherent or incoherent. The Zeeman-sublevel echoes in 3 2S of sodium were observed by using polarization selective detection technique under the excitation condition that the optical T2 (5 × 10-11 s) was much shorter than the pulse width (5 ns). Theoretical analysis also predicts the echoes involving coherence transfer between ground and excited states. 相似文献