Konstanz 1998 – wissenschaftliches Programm

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MO: Molekülphysik

MO 12: Theorie: Dynamik

MO 12.7: Vortrag

Donnerstag, 19. März 1998, 12:30–12:45, M627

Rotational Alignments of Products BaBr from Ba+CH₃Br and Ba+HBr — •Victor Wei-Keh WU¹, Ke-Li HAN², and Guo-Zhong HE² — ¹Victor Basic Research Laboratory,Bielefeld,FRG(http://www.uni-bielefeld.de/ fkure) — ²SKLMRD, Dalian Institute of Chemical Physics, CAS. Dalian, 116023 P.R.China

The results from detailed QCT calculations for both reactions comparing available experimental data within rather broad range of E_rel show that the phenomenon of alignment in Ba+HBr is not only much more significant than Ba+CH₃Br, but also the approximation of l(Ba+HBr) ≈ j’(BaBr) is well acceptable. Comparing with the CPOAM (Constrained Product Orbital Angular Momentum) model, which is approximated for the type of H₁+H₂L→H₁H₂+L, <P₂(j’·k)> = -0.5 + Z_m²(-lnZ_m+1/3), where Z_m = <l’>/l_max, our values of alignment P₂(j’·k) = (3cos²θ-1)/2 shows: Ba+HBr is well suitable to be described with such approx. than Ba+CH₃Br. The values of P₂ for Ba+HBr approach nearly the asymptotic value -0.5. Whether the reaction mechanism runs more via Stripping or Migration at certain E_rel can be concluded according to how far is the deviation between the values from CPOAM and ours, is uncertain. This approx. is only suitable for reaction, where L is much lighter than both H₁ and H₂, and there is no or only little of internal degrees of motions in L. ^*Wu thanks the financial support by VBR (75%), DFG., and SKLMRD. Ref. 1. Bull. Chem. Soc. Jpn. (Submitted), 2. Chem. Comm. (To be submitted)