6-Methylquinolinium Dichromate를 이용한 치환 벤질 알코올류의 산화반응 속도

국문 초록 (Abstract)

H₂O 용매 하에서 6-methylquinoline 과 chromium trioxide의 반응을 통하여 6-methylquinolinium dichromate [(C10H9NH)2Cr2O7]를 합성하여, 적외선분광광도법(IR), 유도결합 플라즈마(ICP) 등으로 구조를 확인하였다. 여러 가지 용매 하에서 6-methylquinolinium dichromate를 이용하여 벤질 알코올의 산화반응을 측정한 결과 유전상수(ε) 값이 큰 용매 순서인 시클로헥센 < 클로로포름 < 아세톤 < N,N-디메틸포름아미드 용매 하에서 높은 산화반응성을 보였다. 산 촉매(H₂SO₄)를 이용한 DMF 용매 하에서 6-methylquinolinium dichromat는 벤질 알코올과 그의 유도체들(p-OCH3, m-CH3, H, m-OCH3, m-Cl, m-NO₂)을 효과적으로 산화시켰다. 그리고 전자받개 그룹들은 반응속도가 감소한 반면에 전자주개 치환체들은 반응속도를 증가시켰다. 또한 Hammett 반응상수(ρ) 값은 -0.67(303K) 이였다. 그러므로 본 실험에 서 알코올의 산화반응 과정은 속도결정단계에서 수소화 전이가 일어나는 메카니즘임을 알 수 있었다.

다국어 초록 (Multilingual Abstract)

6-Methylquinolinium dichromate[(C10H9NH)2Cr2O7] was synthesized by the reaction of 6-methylquinoline with chromium trioxide in H₂O, and characterized by IR, ICP. The oxidation of benzyl alcohol using 6-methylquinolinium dichromate in various solvents showed that the reactivity increased with the increase of the dielectric constant(ε), in the order: cyclohexene ＜ chloroform ＜ acetone ＜ N,N- dimethylformamide. In the presence of hydrochloric acid(H₂SO₄ solution), 6-methylquinolinium dichromate oxidized benzyl alcohol and its derivatives(p-OCH3, m-CH3, H, m-OCH3, m-Cl, m-NO₂) smoothly in DMF. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant(ρ) was -0.67(303K). The observed experimental data was used to rationalize the hydride ion transfer in the rate-determining step.

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