Abstract |
CHCl3, CHCl3 : CH2Cl2(1:1) 및 CH2Cl2 용매 중에서 치환 aniline[aniline, N,N-dimethylaniline(N,N-DMA), 2,6-dimethylaniline(2,6-DMA) 및 2,4,6-trimethylaniline(2,4,6-TMA)]과 iodine간의 charge transfer complex 형성에 대하여 전도도법을 이용하여 속도론적으로 조사하였다. 초기에 일시적으로 생성된 outer charge transfer complex가 inner complex로 변환되는 과정에 있어서 치환 aniline의 electron donor 및 polar medium으로서의 작용에 대하여 고찰해 보았다. 또한 변환의 빠르기는 medium의 dielectric environment와 치환 aniline의 pKa값에 의존하였으며 2,4,6-TMA, 2,6-DMA, aniline, N,N-DMA의 순서로 증가하였다. Chloroform 용매 중에서 2.5M 농도의 치환 aniline에 대히서 얻은 △H≠값은 N,N-DMA, 3.47kcal/mol:aniline, 4.25kcal/mol:2,6-DMA, 7.79kcal/mol:2,4,6-TMA, 7.96kcal/mol:△S≠값은 모든 aniline에 있어서 -41~-55cal/mol·K의 큰 음의 값을 나타내었다. Formation of charge transfer complex between iodine and substituted aniline [aniline, N,N-dimethylaniline(N,N-DMA), 2,6-dimethylaniline(2,6-DMA), 2,4,6-trimethylaniline(2,4,6-TMA)] in CHCl3, CH2Cl2 : CHCl3 (1 : 1), and CH2Cl2 have been studied kinetically by using conductivity method. In the transformation of initially formed outer charge transfer complex to inner complex, the effects of substituted aniline as electron donor and polar medium on the reaction were investigated. The rate of transformation depend on the dielectric contribution of medium and pKa value of substituted aniline. The order of rate increasing is 2,4,6-TMA, 2,6-DMA, aniline, and N,N-DMA. The activation enthalpy △H≠ for 2.5 M-substituted aniline in CHCl3 at 25℃ is respectively N,N-DMA, 3.47 kcal/mol; aniline, 4.25 kcal/mol; 2,6-DMA, 7.79 kcal/mol and 2,4,6-TMA, 7.96 kcal/mol; and activation entropy △S≠ is large and negative value of -41 ∼ -55 cal/mol·K. |
