Acta Phys. -Chim. Sin. ›› 1985, Vol. 1 ›› Issue (05): 460-463.doi: 10.3866/PKU.WHXB19850510

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STUDIES ON TRANSITION-METAL PERHALOPHENYL COMPOUNDS
Ⅸ. KINETICS AND MECHANISM OF SUBSTITUTION REACTIONS OF CHLORO-BIS (DIPHENYLMETHYLPHOSPHINE) (PENTACHLOROPHENYL)-NICKEL(Ⅱ) WITH PYRIDINE AND SUBSTITUTED PYRIDINE

Zhang Qiyan; Li Yuejin; Chen Jinchang; Chen Rongti; Zhang Zhengzhi; Wang Xukun   

  1. Department of Chemistry, Nankai University; Institute of Elemento-organic Chemistry, Nankai University
  • Received:1984-12-17 Revised:1985-02-25 Published:1985-10-15

Abstract: The kinetics of nucleophilic substitution reactions between trans-(Ph_2PMe)_2 Ni(C_6Cl_5)Cl and pyridine and various substituted pyridines in ethanol has been studied. In the presence of NH_4Cl (0.004M), the pseudo-first-order rate cons tant can be expressed by
k_(obs)=(k_1′[am]/(k_2/k_3)[Cl~-]+([am])+k_(am)′[am])
The rate constants and their corresponding activation parameters have been measu red and a reaction mechanism is proposed. The results show that the rate of sub stitution reactions is primarily governed by steric effect rather rather than the basicity of the entering group.