Abstract
(C4H4N2H)2Cr3O10 has been prepared by the reaction of C4H4N2 with CrO3 in water. (C4H4N2H)2Cr3O10 was identified by elemental analysis, IR, UV-Vis and TG-DTA-TMA system. The oxidation of benzyl alcohol by (C4H4N2H)2Cr3O10 in organic solvents showed that the reactivity increased with the increase of the dielectric constant. The oxidation of alcohols was examined by (C4H4N2H)2Cr3O10 in CH2Cl2. As a resuit, (C4H4N2H)2Cr3O10 was found as efficient oxidizing agent that converted benzylic alcohol, allylic alcohol, saturated primary alcohol, secondary alcohols to the corresponding aldehydes or ketones(70%~96%). The selective oxidation of alcohols was also examined by (C4H4N2H)2Cr3O10 in CH2Cl2. (C4H4N2H)2Cr3O10 was selective oxidizing agent(10%~96%) of benzylic alcohol, allylic alcohol, saturated primary alcohols in the presence of secondary ones. In the presence of DMF. solvent with acidic catalyst such as HCl. (C4H4N2H)2Cr3O10 oxidized benzyl alcohol and its derivatives. The Hammett reaction constant was -0.70(303K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.
(C4H4N2H)2Cr3O10을 제조하여, 원소분석, IR, UV-Vis, 열무게-시차열분석, TG-DTA-TMA system 등으로 착물의 구조 및 특성을 확인하였다. 여라 가지 용매에서 (C4H4N2H)2Cr3O10을 이용한 벤질 알코올의 산화 과정을 실험한 결과, 용매들의 유전상수 값이 증가함에 따라 산화반응이 증가하였다. 또한 CH2Cl2 용매 하에서 (C4H4N2H)2Cr3O10을 이용한 알코올들의 산화 과정을 실험한 결과, benzylic alcohol, allylic alcohol, saturated primary alcohol, secondary alcohol들을 알데히드 혹은 케톤(70% ~ 96%)으로 전환시키는 효율적인 산화제였다. CH2Cl2 용매 하에서 (C4H4N2H)2Cr3O10을 알코올 혼합물들의 산화 과정을 측정한 결과, secondary alcohol의 존재하에서, benzylic alcohol, allylic alcohol, saturated primary alcohol을 선택적으로 산화(10% ~ 96%) 시켰다. 산(HCl) 촉매를 첨가 후, DMF 용매 하에서, (C4H4N2H)2Cr3O10은 벤질 알코올과 그 치환체들을 효율적으로 산화시켰다. Hammett 반응상수(ρ) 계산 결과 -0.70(303K)를 나타내었다. 본 연구에서 알코올의 산화반응은 속도결정단계에서 수소화 전이가 일어났다.