Konstanz 1998 – wissenschaftliches Programm

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MO: Molekülphysik

MO 7: Poster: Cluster, Stoßprozesse

MO 7.27: Poster

Dienstag, 17. März 1998, 16:00–18:00, PF

Kinematical Transformation of Ba+CH₃Br/HBr→BaBr+CH₃3/H within 0.01-3.0 eV — •Victor Wei-Keh WU¹, Ke-Li HAN², and Guo-Zhong HE² — ¹Victor Basic Research Laboratory,Bielefeld,FRG — ²SKLMRD, Dalian Institute of Chemical Physics, CAS. Dalian, 116023 P.R.China

H influences unimaginably strong that Migration contributes more predominantly than Stripping. Because an intermediate step is involved, it takes a certain time for the rearrangement (Migration) of the participating atoms as well as shift of scattering angles of BaBr into the region of 70^o-90^o. To explain the reactions with electron jump is suitable: Because the electronegativity of H (2.2) or C (2.5) is not very different from that of Br (2.7), the Ba atom (1.0) can be easily positively charged after loosing one electron to H or CH₃ of CH₃Br first during the approach, then positively charged Ba picks negatively charged Br up, after the negative charge has been transferred from H or CH₃ to Br. Transfer of the negative charge from CH₃ to Br and change of the attraction of Ba with CH₃ into with Br is more quickly than what in Ba + HBr. Fraction of Stripping of BaBr in Ba + CH₃Br is generally larger than Migration and BaBr are scattered at smaller angles ω. High v’_BaBr can be induced efficiently by the attraction between Ba and Br with different charges after electron jump, transfer of negative charge and Migration of Ba. ^*Wu acknowledges the sponsorships by VBR(75%), DFG., and SKLMRD. Ref. 1. Chem.Lett., 309, 841 (1997), 2. Bull. Chem. Soc. Jpn. (Submitted)