Chinese Journal of Magnetic Resonance ›› 2001, Vol. 18 ›› Issue (4): 321-328.

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NMR STUDY OF DIFFUSION-CONTROLLED EXCHANGE OF HALOGENS IN THE MIXTURES OF TIN (IV) TETRAHALIDES

ZHANG Yong-hong, MAO Xi-an*   

  1. State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan Institute of Physics & Mathematics, The Chinese Academy of Sciences, Wuhan 43007 1, China
  • Received:2001-08-02 Revised:2001-09-03 Published:2001-12-05 Online:2001-12-05
  • About author:*Correspondence author
  • Supported by:

    国家自然科学基金资助项目(No.29725307).

Abstract:

The dynamics of halogen exchange in the mixtures of SnCl4 and SnBr4 at di ffer ent concentrations were studied by using 119Sn NMR spectroscopy. Th e spin lattice relaxation times (T1) and the exchange rate constants (k) were measur ed. The res ults show that the magnetization exchange rate constants in this system are prop ortional to the apparent relaxation rates. It is believed that the system is in  the slow motion limit, since the T1/T2 ratio is very large. Theories ind icate th at the spin-lattice relaxation times are proportional to the molecular reorien ta tion correlation time and the correlation time is related to diffusion. It can be concluded that halogen exchange in this system is “diffusion-related”.

Key words: Tin(IV) tetrahalides,  119Sn NMR,  Chemical exchange,  Relaxation rate,  Self-diffusion

CLC Number: