Kinetics and Mechanism of the Hydrolysis of 1-Halo-3-Phenyl-1,2-Propadienes

1-Halo-3-Phenyl-1,2-Propadiene들의 가수분해에 대한 반응속도론적 연구

  • Lee, Kang Ryul (Department of Chemistry, the Catholic Universitry of Korea) ;
  • Yoo, Hil Ra (Department of Chemistry, the Catholic Universitry of Korea) ;
  • Jung, In Chan (Department of Chemistry, Hanseo University) ;
  • Huh, Tae Sung (Department of Chemistry, the Catholic Universitry of Korea)
  • Published : 19970700

Abstract

Extended Huckel Molecular Orbital (EHMO) calculations of haloallene (1-halo-3-phenyl-1,2-propadiene) derivatives have been performed. From the MO calculation data and kinetic experimental results, the mechanism for the hydrolysis of haloallenes is proposed.; Below pH 8.0, the hydrolysis proceeds through a solvent assisted $S_N1$ mechanism involving the formation of carbonium ion Ⅱ as intermediate. However above pH 9.5, the hydrolysis proceeds through an $S_N2'$ mechanism via transition state Ⅲ.

haloallene 유도체(1-halo-3-phenyl-1,2-propadiene)에 대해 EHMO계산을 하여, 에너지적으로 안정한 haloallene 분자의 구조를 결정하였다. MO 계산 데이터와 속도론적인 실험 결과로부터 haloallene의 가수분해반응 메카니즘을 제안하였다. pH 8.0 이하에서는 중간체로 carbonium ion Ⅱ이 생성되는 용매도움 $S_N1$ 메카니즘에 의해 진행된다. 그러나 pH 9.5 이상에서는 전위상태 Ⅲ를 거치는 $S_N2'$ 메카니즘에 의해 진행된다.

Keywords

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