CAJ | 학술논문

利用时间分辨的激光闪光光解技术研究了乙腈-水混合溶液(1∶1,V/V)中2-甲基萘醌(通常称为维生素K3)的激发三重态对色氨酸、酪氨酸的光敏氧化机理.通过瞬态吸收光谱的变化可以推断维生素K3的激发三重态可以与色氨酸、酪氨酸发生电子转移反应,反应形成的维生素K3阴离子自由基的吸收峰可以直接从瞬态吸收谱图中观察到.维生素K3与色氨酸、酪氨酸的电子转移反应的速率分别为1.1×109和0.6× 109 L·mol-1 ·s-1.吉布斯自由能(△G)的计算结果表明维生素K3的激发三重态与色氨酸、酪氨酸电子转移反应在热力学上是可行的.
이용시간분변적격광섬광광해기술연구료을정-수혼합용액(1∶1,V/V)중2-갑기내곤(통상칭위유생소K3)적격발삼중태대색안산、락안산적광민양화궤리.통과순태흡수광보적변화가이추단유생소K3적격발삼중태가이여색안산、락안산발생전자전이반응,반응형성적유생소K3음리자자유기적흡수봉가이직접종순태흡수보도중관찰도.유생소K3여색안산、락안산적전자전이반응적속솔분별위1.1×109화0.6× 109 L·mol-1 ·s-1.길포사자유능(△G)적계산결과표명유생소K3적격발삼중태여색안산、락안산전자전이반응재열역학상시가행적.
Laser flash photolysis was used to study the photosensitized oxidation mechanism of vitamin K3,commonly known as 2-methyl-1,4-naphthoquinone (MQ),with tryptophan (TrpH) or tyrosine (TyrOH) in acetonitrile/water (1∶1,V/V) solution.The triplet state of MQ reacted with TrpH or TyrOH by electron transfer with the formation of a MQ anion radical,which was directly observed in the transient absorption spectrum.The rate constants of the electron transfer reactions were determined to be 1.1 ×109 and 0.6×109 L· mol-1· s-1 for TrpH and TyrOH,respectively.The free energy changes (△G) of the reactions showed that the proposed electron transfer steps are thermodynamically feasible.